Need help to spec a microcontroller.

​Hello! I am looking for a bit of guidance as I have limited knowledge in programming Microcontrollers...amateur experience covers a bit of Arduino and LabVIEW (mostly). My goal is to have an LCD display (Module size +- 65 x 40 mm, with SPI or I2C Comms, Monochromatic) to display small error message/codes and other information as for example temperature, speed, Test number and Timer. I do not know what would be the best Microcontroller to use that is off the shelf, that will still be in production for years to come and is "less complicated" to learn...from what I have read, perhaps the best microcontroller might be the Atmel just don't know what model (am open to other suggestions) Also there shall be 20 push buttons connected to the microcontroller. All that the microcontroller does is read the buttons as a byte and send it to another controller and receive information from that controller to know what information to display on the LCD. It shall also inform the controller of any error that it is experiencing.  I do hope that I am providing with clear and enough information so that someone could point me in the right direction.  Thank you in advance.

Topic by Art_Rob   |  last reply

Arduino monitoring Paypal Payments

Would an Arduino Wifi Shield allow an arduino to trigger something after a paypal payment is made?

Topic by Brooklyntonia   |  last reply

Control a Magnet Fidget Spinner with Arduino and Electromagnets?

Hello! I was wondering if it would be possible to control a magnet fidget spinner with Arduino and electromagnets. Any ideas? The basic concept could be something like this:  Take a common 3 bladed fidget spinner and attach a magnet to each blade end. Build an Arduino contraption with a sensor that observes the spinning of the fidget. Add and electromagnet to Arduino. By repeatedly turning on and off the electromagnet with proper timing and observation you should be able to accelerate (or brake) the spinning of the fidget... right? 

Topic by Vesa Seppänen   |  last reply

Can You use a GPRS with a landline phone?

I have wanted to this but can't find info But what I wanted to do was to set up and Arduino with a GPRS shield but instead of it being the phone I wanted to have it hook up to an old rotary dial phone and have it work like it's plugged into the wall and the arduino/shield would be in a box but the question remains, can that be done or is it not possible?

Topic by Zuma07   |  last reply

Grounding yourself w/ a suitable ESD wristband without a PSU

So I do not own a laptop or any personal computer as I have no need for either of them (until I get deeper into electronic tinkering with an Arduino, etc). I do have an ESD wristband that I bought from a local computer store that has an alligator clip on the end. I've done a bit a research, but only getting mixed answers as to how I can ground myself without a PSU. I'd like to guarantee that I don't fry any of the beginner electronic projects that I plan on doing. How exactly am I supposed to ground myself with an ESD-wristband? I do own rubber Nike sandals (open-toe) that I don't mind wearing to help avoid frying any electronics, have a wooden surface on my workbench, but my workstation area is all on carpet. Thanks in advance!

Topic by TXVisual   |  last reply

Dir-300 as Wifi repeater

Hello, I have an AP in my house which broadcasts our wireless Internet signal throughout our house. Unfortunately there is a spot in my house where the signal is not received. I have a spare dlink dir-300 router which I installed custom firmware on (dd wrt). Can someone please help me use it as a wireless repeater. I want it to boost the signal of my other router. Dd wrt has a repeater function, but my router is an atheros chipset so it is not native on my device. P.s: I don't really want some cheap wifi booster made of tinfoil :p . Thanks in advance, Sam

Topic by Bituser   |  last reply

HP iPAQ - what can I do with it?

I've got an HP Ipaq HX2100 gathering dust - I used to use it for reading ebooks on, but now use my blackberry. I was going to put it on ebay, but it wont sell for much, so I'm looking for idea's for what I could use it for. Doesn't have wifi on it so it kinda limits the options I suppose. Any idea's? Cheers, Pha3dr0n

Topic by pha3dr0n   |  last reply

Looking for someone to help buld an Arduino linear measurement project.

I'm looking for someone to help me build an Arduino linear measurement project. I need to measure less than 6" stroke with some accurate repeatability. I'm willing to pay for the programming and any parts I might need. Email me if you are interested in working on this with any questions you have... Thanks, 

Topic by rpmlou 

What choice of motor for a robot

Hello, I'm making researches about electric motors, I know very little about them and it seems to be a vast world. I don't have any detailled project yet, but I'd like to make a small robot that would be capable to move, that implies using electric motors. Forums have many useful data about them, but what it lacks is precise user reviews: what type of motor would you use the most, and why? Is it simpler to use servomotors over DC, or brushless? Prics must be a criteria of choice, but can I found cheap motors with good performance? Thank you very much for your help

Topic by armandbon   |  last reply

Outdoor RGB LED Strip Failure

Hi all,  I've had quite a modest installation of RGB LED tape (45 meters ish, split into more manageable circuits) around the perimeter of my decking. This uses the commonly available 5050 RGB LED Strip light, the type with the epoxy covering the tape and also an outer sheath to protect it from water ingress.  I had heat shrinked the ends and also applied multiple layers of liquid electrical tape where a connection to a 4-core cable was needed. This has held up well for some time.  After about 2 years, I noticed that some of my RGB LED tape runs were sort of 'corrupting' where a small amount of moisture had got in, and shorted the RGB channels so that no matter what I feed into the tape, it always output white (or some other combinations or colours). Still, I ignored this, as it didn;t bother me too much.  These ran back to a central controller, which did the DMX control and amplification of the 12v single.  Anyway, to cut a long story short: Yesterday I smelt smoke.  I was walking around the garden and I noticed that one of the strips had caught fire, at a single point in the middle, and was burning a hole through my decking!  Again, long story cut short, I put this fire out and looked closer. The strip was so badly burnt that I can't determine what went wrong here.  I'm thinking maybe a resistor burnt out and caught fire? The tape has been running 'on' for quite some time (weeks) so this is a possibility.  Another possibility is that there could have been a short between 12v and ground, which caused heat. Now, there aren't any fuses on the 12v rail (fuse and circuit breaker protecting the 240v side) but I wouldn't have thought that this would protect me from a fire anyway!  I'm interested whether anyone else has had a similar experience or has any suggestions as to why this has happened.  I love these RGB LED strips, use them a lot in my house, but after seeing this, I'm not a little more dubious to keep using them.  I'm an electrical engineer (in the making, at University) and this has stumped me!  Thanks Joe

Topic by joearkay   |  last reply

Problem with ATtiny85 IR controlled LED

I am making a LED Light Stick with IR control to change the colour. Uploaded the schematics I made. Is there any mistake ? Do i misunderstand anything ? If yes, please forgive me, I am a complete noob and here to learn. I am going to add a 5v regulator to the Attiny85 power supply. And 380ohm resistor from pin5,6,7 to the corresponding transistor's base pins. I planned to use S8050 NPN transistor. How i calculate the things: 1. The RGB LED Strips i using is rated at 15W/metre @ 5V . Power supply i am using is 6V which is 4xAAA battery .I apply P=IV and get 2.5A/metre of current. Then I calculate current used in 60cm of LED Strips (2.5/100*60) and I get 1.5A current per 60cm. I devided the value by 3 and get 0.5A for each Red, Green and Blue pin. 2. Next step, I found the S8050 DC current gain (hFE/Beta) which is 40 and apply the formula Ic/Ib = B (Ic = 0.5A , Ib = unknown, B=40). I get the Ib of 0.0125A. Which mean i need 0.0125A of current in order to Fully-On the transistor at Ic=0.5A @ 6V. 3.To find the resistor value from Attiny85's Pin, I apply formula Ib = (Vb-Vbe)/Rb (Ib=0.0125, Vb=5 because the power supply of Attiny85 is 5v not 6v , Vbe=0.7V , Rb = Unknown) and i get value of Rb = 376ohm approximate to 380ohm. Another issue is that i didn't really know how to write the code. analogWrite seem didn't work for ATtiny85 sincce there's just 2 analog output for the controller. Or delayMicroseconds will work ? But i could'nt figure out how to write the code. I am very new to arduino. I know i should start at the basic first but i really need to get this project done. And please forgive my language. I didn't know English very well. Thanks a lot.

Topic by Sooncheng 

Project for vector calculus

Hello there, So, for my project in Vector Calculus: The suggestion is that we pick a certain "curve" within a country road. We are to log longitude, latitude and altitude while we drive this "curve" for approximately 15-20 seconds. With the data from the latitude-longitude-altitude "logger", we are to perform the various vector calculus principles we have learned in class. Instead of driving the road, I would like to attach whatever latitude-longitude-altitude logger to a boomerang, and get my curve through flight. Does anyone know which sensor I should be looking for? A bit about me: I am currently an electrical engineering technician in product development for a motor-controls company. I mostly test hardware/software, which is designed by our in-house engineers. I am very comfortable with soldering, visual inspection of PCBs, schematics, and general electrical engineering knowledge. Does anyone have a feasible idea for getting a gps unit onto a boomerang, and be ale to transmit the data to me in real-time? Thanks in advance.

Topic by PaulP292   |  last reply

How to power a brushless motor

How can i power a motor like this (with 3 pins) just to max speed? it's for a propeller clock. thanks

Topic by bfernandes1   |  last reply

500W electric scooter control and instrumentation with Arduino mega

1. Introduction DC 500W motor control with an Arduino mega to limit starting current and to vary the speed of the scooter. The battery is in 24V, 10A.h. The following table summarizes their characteristics: 2. Bibliography: Link download : sketch_escooter_feed_back_reel_V1.ino escooter_ampli_SIMULINK.mdl escooter feed back ISIS.DSN youtube  :  "study trotinette electric e-scooter 100W et 350W, wiring"  youtube;=75&list;=PLfZunVn_gcq7EOurXuWU2sRFmh6CbiUiL Article: «Study of electric scooters 100W and 500W (Arduino), Revue 3EI 2017» Pdf? Book «I realize my electric vehicle» at DUNOD 3. Open loop program To test the programming, we simulate the program in ISIS, as can be seen in the following figure. In addition, we have an LCD display to display data (duty cycle corresponding to the PWM at 32Khz, motor current, motor voltage, action on the pushbuttons, 4 push buttons are used. BP1 to manually increment the duty cycle, BP2 decrement it. BP3 set the duty cycle to 0, corresponding to the brake contact. The speed of the motor is practically proportional to the duty cycle We made our own current amplifier called a step-down chopper but it is possible to buy a shield There are many cards for Arduino to control DC motors especially of low powers and also of great powers as can be observed on the following links. But all these chopper shields measure the current internally but there is no current limitation. In order to have a current limitation, an analog current loop is required using specialized AOP or IC or a fast digital current loop. But what should be the value of the limitation current? The choice of the current value is normally for the 1-hour operation service in order to be able to carry out relatively long climbs without reaching the critical temperature of the engine. In our case, the limitation current must be Limiting motor = Power / Upper battery = 500W / 24V = 20A In addition, the power transistor of the chopper can only support 50A in our case. But in open loop, it has no current regulation, so as not to exceed the maximum current, a ramp of the duty cycle will be used. A 0.1 second interruption routine will be used to measure the voltage of the current (sample measurement, sample). This sampling time is arbitrary but does not allow to be faster than the rise time of the current because the electric time constant of the motor is L / R = 1.5 ms. Open loop operation with a 25.5s (8bit) ramp and 0.1s interrupt routine provides a good understanding of the operation of a DC motor drive. The display will only be done every 0.2s to have a stability of the digits on the screen. In addition, a digital filtering will be done on the current and the voltage on 4 values therefore on 0.4s. [b] Algo open loop [/b] Interrupt Routine All 0.1S Read voltage and current Loop loop (push button scan) If BP1 = 1 then increment PWM If BP2 = 1 then decrement PWM If BP3 = 1 then PWM = 0 Displaying variables every 0.2s Code: [Select] // include the library code: #include #include #include #define SERIAL_PORT_LOG_ENABLE 1 #define Led     13       // 13 for the yellow led on the map #define BP1     30       // 30 BP1 #define BP2     31       // 31 BP2           #define BP3     32       // 32 BP3 #define LEDV    33       // 33 led #define LEDJ    34       // 34 led #define LEDR    35       // 35 led #define relay   36       // 36 relay #define PWM10    10      //11   timer2    LiquidCrystal lcd(27, 28, 25, 24, 23, 22); // RS=12, Enable=11, D4=5, D5=4, D6= 3, D7=2, BPpoussoir=26 // Configuring variables unsigned   int UmoteurF = 0;  // variable to store the value coming from the sensor unsigned   int Umoteur = 0; unsigned   int Umoteur2 = 0; unsigned   int Umoteur3 = 0; unsigned   int Umoteur4 = 0; unsigned   int ImoteurF = 0;  unsigned   int Imoteur = 0; unsigned   int Imoteur2 = 0; unsigned   int Imoteur3 = 0; unsigned   int Imoteur4 = 0;            byte Rcy=0 ;    // 8bit duty cycle unsigned    int temps; // the setup function runs once when you press reset or power the board void setup() {   pinMode(Led, OUTPUT);   // Arduino card   pinMode(LEDV, OUTPUT);   pinMode(LEDR, OUTPUT);   pinMode(LEDJ, OUTPUT);   pinMode (PWM10,OUTPUT);     // Pin (10) output timer2   //  digitalWrite(LEDV,LOW);   Timer1.initialize(100000);         // initialize timer1, and set a 0,1 second period =>  100 000   Timer1.attachInterrupt(callback);  // attaches callback() as a timer overflow interrupt   lcd.begin(20, 4);    Serial1.begin(9600);   TCCR2B = (TCCR2B & 0b11111000) | 0x01;         //pin 10  32khz                                                   //   //   analogWriteResolution(bits) lcd.setCursor(0,1); lcd.print("Rcy"); lcd.setCursor(10,1); lcd.print("Um"); lcd.setCursor(5,1); lcd.print("Im"); lcd.setCursor(10,1); lcd.print("Um"); lcd.setCursor(20,1); // 4 lines display * 20 characters lcd.print("BP1+"); lcd.setCursor(25,1); lcd.print("BP2-"); lcd.setCursor(29,1); lcd.print("BP3=0"); } // Interruptions  tous les 0.1s void callback()  { temps++; //toogle state ledv for check   if ( digitalRead(LEDV)== 1 ) {digitalWrite(LEDV,LOW);}     else {digitalWrite(LEDV,HIGH);}     analogWrite(PWM10,Rcy);   // frequency Umoteur=analogRead(A0); Imoteur=analogRead(A1); Imoteur2=Imoteur; Imoteur3=Imoteur2; Imoteur4=Imoteur3; ImoteurF=(Imoteur4+Imoteur3+Imoteur2+Imoteur)/4 ; Umoteur2=Umoteur; Umoteur3=Umoteur2; Umoteur4=Umoteur3; UmoteurF=(Umoteur4+Umoteur3+Umoteur2+Umoteur)/4 ;   }// End routine // Loop corresponding to main function void loop() {    // BP + LED   if ((digitalRead(BP1))==1) {     lcd.setCursor(20,0);      // Column line     lcd.print("BP1");     digitalWrite(LEDR, LOW);        digitalWrite(LEDJ, LOW);     Rcy++;                        // PWM incrementation     if ( Rcy>254)  {Rcy=254;}     delay(100);               //8bits * 100ms = 25S increment 25ssecond slope     }        if ((digitalRead(BP2))==1) {     lcd.setCursor(20,0);     lcd.print("BP2");             Rcy--;      if ( Rcy<2)  {Rcy=2;}  // PWM almost at 0, engine stop         delay(100);      digitalWrite(LEDR, HIGH);     digitalWrite(LEDJ, HIGH);     }   if ((digitalRead(BP3))==1) {     lcd.setCursor(20,0);     lcd.print("BP3");      Rcy=2;               // PWM almost at 0, engine stop     } if (temps>=2)  { lcd.setCursor(0,0); lcd.print("                "); // Erase line lcd.setCursor(0,0);     lcd.print(Rcy); lcd.setCursor(5,0); ImoteurF=(ImoteurF)/20;     //resistance (5/1024)*(10/0.25ohm) si ACS712 66mV/A                            // For resistance 1ohm (ImoteurF) / 20; Simulation 5/25 lcd.print(ImoteurF); lcd.setCursor(10,0); UmoteurF=UmoteurF*10/38;                              //10/38   10/30 simula if (Umoteur>ImoteurF){UmoteurF=UmoteurF-ImoteurF;  }  //U-R*I lcd.print(UmoteurF); temps=0; }// End if time    } // End loop Since there is a limit of 9000 characters in the forum below Open loop program feature previous The interrupt routine lasts only 250 microseconds, the loop of the main program which scans the action of push buttons is 13micros and the display time of all data is 11ms. Thus, it is possible to improve the sampling period and thus the speed of the regulation of the current. The Arduino makes it possible to make the instrumentation of the scooter so to know the power, the consumption in Ah and Wh, to measure the speed, to know the consumption according to Wh / km, to measure the temperature of the engine, Have a safe operation. But for now we will see how to limit the current 4. Closed loop program, limited current control The sampling period will increase to 0.01 seconds (interrupt routine) If the current is less than the desired value, then the duty cycle can be increased or decreased to the desired value which is the setpoint. On the other hand, if the motor current is greater than the limiting value, there is a rapid decrease in the duty cycle. So as not to exceed the value of the duty cycle if it is saturated to 254 maximum and to the minimum value 6. Code: [Select] if (Imoteur<4000)                    // No current limitation at (20A * 10) * 20 = 4000   {if (consigne>Rcy)   {Rcy=Rcy+1;}   // Pwm ramp + 1 * 0.01second pure integrator    if (consigne    if ( Rcy>254)  {Rcy=254;}           // Limitation of duty cycle    analogWrite(PWM10,Rcy);   // Frequency 32kHz timer2}         } if (Imoteur>4000)  { Rcy=Rcy-5;              // No current filtering, to be faster                     if ( Rcy<6)  {Rcy=5;}       // Rcy is not signed, nor the PWM therefore Rcy minimum must not be less than 6                   analogWrite(PWM10,Rcy);   // Frequency 32kHz timer2}                        } 5. Closed Loop Program, Limited Current Control with Acceleration Handle An acceleration handle provides a 0.8V voltage when not operated and a 4.5V voltage when the handle is fully engaged. Instead of using pushbuttons to increase or decrease the speed setpoint, an acceleration handle will be used Code: [Select] Upoignee=analogRead(A3); // The relation in Upoign and the setpoint which corresponds to the duty cycle corresponds to if (Upoignee>100) { consigne=(Upoignee/2);     //0=a*200+b    et 255=a*800+b                      consigne= consigne-100;                   }                            else { consigne=0;   }               if (Upoignee<100) { consigne=0;  }     // redundancy     6. Temperature and safety program of the motor with the current measurement The outdoor temperature measurement can be easily performed by the LM35 component which charges 0.01V by degrees Celsius Code: [Select] temperature=analogRead(A2); //lm35 0.01V/°C temperature=temperature/2;       // Temperature coefficient lcd.setCursor(5,2); lcd.print("      "); lcd.setCursor(5,2); lcd.print(temperature);   // Display in ° C lcd.setCursor(9,2);      // Erasing secu display lcd.print("     ");   if (temperature>80 ) {lcd.setCursor(9,2);         // If motor external temperature is above 80 ° C                      lcd.print("secuT");                       Rcy=0;} In addition, thermal safety by measuring the motor current will be added. If the limitation current is greater than 10s then the motor will no longer be powered for 30s. A "secu" display will appear on the LCD display. This safety makes it possible to cut the motor on slope too high and when blocking the engine but it would be necessary to add the measurement of the speed in the latter case Code: [Select] if (timesecurite>=10000 ) {flagarret=1;      // If limitation current for a current of more than 10s                               timerepos=0;                               consigne=0;                               Rcy=0;                                 timesecurite=0;}       //   Then stop engine during a downtime    if (flagarret==1 ) {lcd.setCursor(9,2);         // If limiting current for a current of more than 20s                      lcd.print("secU");  }     //   Then stopping the motor for a stop time and display                                                     if (timerepos>=30000 &&  flagarret==1) {flagarret=0;                                           lcd.setCursor(9,2);      // After a rest time here of 30s                                            lcd.print("       ");   }   The display can be observed if the temperature is above 80 ° C Thermal safety by measuring the motor current (digital thermal relay) which allows to know the image of the internal temperature of the engine would be ideal. But for this, it is necessary to know well the thermal modeling of the motor. 7. Measurement of the energy capacity of the battery The energy capacity of a battery is in A.H, we will display the value in mA.H to have a high accuracy. The capacity will be in A.Second in the following equation. So to have in mA.H, it will be divided by capacity by3600. Capacity (A.s) n = I * Te + Cn-1 with Te = 0.01s and I multiplied by 10 So in the interrupt routine Code: [Select] capacity=ImoteurF+capacity ; And in the display Code: [Select] lcd.setCursor(0,3); // Display of energy capacity lcd.print("C mA.h="); capacity1=capacity/(18000);   //18000=3600*5  5=> Current measurement coefficient lcd.print(capacity1); To check a current of 10A with an adjustable resistor and after 30s, the capacity must be 83mA.H 8. Power and modeling with SIMULINK Modeling helps to understand the vehicle and its control. In addition, it is possible to compile the control part directly into the Arduino program from simulation under Simulink. But it will not be possible to simulate the instrumentation with the LCD display. In the following figure, we can observe the simulation of the programming of the chopper with the current limitation with Simulink. In the following figure, the green box shows the duty cycle control to vary the speed and the red border the current limitation. The controller of the control is here a simple integrator but it is possible to carry out a multitude of control. In the previous figure, it can be observed that the current is well limited to 25A from 2s to 9.5s. Then, the current reaches 10.8A under established speed regime at 22.5km / h. The dynamics are similar to the tests carried out. With a slope of 5%, the cyclic ratio reaches only 100% as can be seen in the following figure. The speed will reach painfully 19km / h with a current of 24A and a motor power of 580W. See article: Study of electric scooters 100W and 500W (Arduino), 9. First conclusion It is easy to control a 500W DC motor with an Arduino and some components So repair many scooters that are in DC motors. But it takes some knowledge (automatic, engine) to know how to properly manage the engine and limit its current so as not to damage it The display of the speed, the distance, the operating time to know the / km can also be realized with a menu 2. The .ino program as an attached file, But it is not possible to put an attached file in ISIS electronic labcenter? What is this forum? It would be desirable that the compiler could generate the.cof to debug in Isis and test the program line by line .... Arduino still has to make a lot of effort to be on the same level as other microcontrollers 10. speed measurement (tachometer) Velocity measurement is carried out using a hall effect sensor SS495 or A1324 which counts each revolution of the wheel. It is enough to enter the perimeter of the wheel of the scooter (130mm of radius therefore 0.816m in the case To have the speed, it is enough just to divide the number of turn of wheel on an arbitrary time of 1s to have a minimum speed of 0.81m / s therefore of 2.93 km / h. In addition, an average filter with 3 values will be used to display the speed. At 25km / h, there will be 8.5 laps. To count the turns, an external interrupt routine will be used on input INT0 21 of the mega card. To simulate the speed, a pulse on input 21 will be used with a duty cycle of 10%. Code: [Select] void INT0b21() {   Tspeed++;   // External interruption to count the number of turns } // In the set up declare the interrupt routine when the 5V edge of the magnet detection is done   attachInterrupt(digitalPinToInterrupt(21), INT0b21, RISING );  // External interruption // In loop if (temps09>=5)  {        // 1 second loop lcd.setCursor(13,2);      // Erasing speed lcd.print("kph     "); lcd.setCursor(16,2); speed1=Tspeed*2937;      //1tour*816*3.6/1s=2.937km/h speed2=speed1;           //Tspeed (rate/seconde) speed3=speed2; speedF=(speed1+speed2+speed3)/3000;   // To put in kph lcd.print(speedF,1);    // Display to the nearest tenth Tspeed=0;   // Reset counter temps09=0;  //reset time } To improve the accuracy of the velocity measurement, it is possible that the sampling time of the velocity measurement is dependent on the velocity. For example: For speeds less than 10km / h sample at 1second, but above 10km / h sample at 2 seconds. 11. Distance measurement for autonomy The distance corresponds to the total number of turns of the wheel multiplied by the perimeter of the wheel. So do not set the number of turns to 0 for each sample. On the other hand, the reset of the distance will be done when pressing the reset of the Arduino Mega. The distance display will be displayed to the nearest second. At 32km / h, it will take 2 minutes to do 1km as can be seen in the following figure: Code: [Select] void INT0b21() {   Tspeed++;   // External interruption to count speed   nbrRate++; } lcd.setCursor(13,4);      lcd.print("km      ");  // distance=(nbrRate*816)/1000;  //distance m distance=distance/1000;  //distance km lcd.setCursor(15,4);      lcd.print(distance,1);  You can observe the electrical installation with the chopper, the arduino, and the display when the program is set up 12. Synthesis The RAM space is used only at 4% and ROM space at 3%, for an Arduino mega. So we could take an arduino a little smaller. But, there are 8 Lipo cells to make the 24V power supply to power the engine via the chopper. Therefore, the voltage measurement of each element will be on the Arduino with a JST connector. This measurement makes it possible to know if a cell with an internal resistance which begins to pose a problem and to know if the balancing of each cell has indeed been carried out. It is possible to switch to 36V with 12 cells also with the arduino mega without using an external shield that multiplex 24 analog inputs on input A0 It is possible to send all data to a smartphone via Bluetooth HC06 via pins 20, 21, RX1 and TX1. But the application under android realized under JAVA Studio can not be shared on this forum. This part will not be explained. After having made the instrumentation of this scooter, a study should be carried out on the precision of the measurements, it is possible to read "Instrumentation of a low-power electrical motor vehicle" eco marathon "type Revue 3EI N ° 81, July 2015

Topic by Iutgeiisoissons 

The Bravery of Being Out of Range: A Technological Revolution

The 18th century gave us the beginning of the Industrial Revolution. Purpose-built factories for the new industries such as iron and textiles. New and improved methods of transportation, communication and production. It changed the way people lived / worked and it created / inspired a lot of what we still see and use today. This revolution had its negatives too. Jobs were lost to the industrial machines that did it better and faster, the poor and the working classes often had to endure grim living and working conditions. The black gold mined from underground, fuelled our thirst for advancement. Now in the 21st century, we are in the midst of the Technological Revolution. Ubers, drone deliveries, driverless cars and trucks, AI, Google, Facebook, Amazon Alexa, unmanned military vehicles, war by remote control and the bravery of being out of range. The drones, AI, robots and automation may not only take away our jobs, but potentially the need to leave the house or to have any real-world face to face interactions. They could re-define our lives, for better or for worse. Are you fearful? Wary? Or do you embrace the changes going on all around us?

Topic by ThirdEarthDesign   |  last reply

Wireless FM microphone real time voice/play transmitter

Hello I am looking to buy/build a small FM wireless transmitter with built in microphone (similar to karaoke but not exactly ) to transfer voice or sound  from playing  musical instrument  to earphone. It is meant only for practice purpose so does not need  high power, the distance between the microphone (the transmitter ) to earphone  is like from mouth to ear a few centimeters say about  50 cm. I am electronic junior engineer and have knowledge and experience in electronics mechanics and wave buy. Before trying to develop a new product  I was looking for a readymade shelf product. The first way I have searched the internet and reached manufacturer of Bluetooth solutions because of the plenty of Bluetooth earphone that are on the market, but quit a short time after I got some answers from the the Techs engineers  of the manufacturers that Bluetooth will not be my solution because It was not originally designed for true real time transmitting. The main problem is the latency time because there is a delay between the voice or play start until I hear it in the earphone there is improved in Bluetooth 4.1 and 4.2 that is 38 MS and may be not enough while fast playing, So as I was advised I started looking in the RF FM area. FM transmitters are long time in the market of stages and performers, there are high power grate quality transmitters that cost hundreds of dollars. Here is the summary of what I need :        I will need the smallest device (PCB) can be like FM spy bug transmitter. built in microphone (on the PCB ) , built in battery compartment (on the PCB ),built in antenna a copper loop on the PCB (no wire) Since there may be some problems like saturation of microphone or other problems with band width or  sound and sensitivity, sensitivity and control for the Microphone is important. Easy calibration of  tuning and stability , may be digital tuning is better. One option is to use the standard of radio FM 88-108 , but it possible that I can use FM VHF or UHF system that have both transmitter and receiver . If there are no ready made products thatn I can easy build a kit , or from schematic diagrams I will be thank full if you have any ideas. Nevat Ben Haim Recomp Computers

Topic by Nevat   |  last reply

Waterproofing micro USB B port on waterproof project box

Heyo, I am in need of a way to waterproof a micro usb B port (or water-resist since the port will only at most be rained on) of a microcontroller (the Adafruit HUZZAH)  in order to access the USB port (for charging and reprogramming) without having to open the case. I am open to any ideas that would keep the box watertight and not having a wire hang out of the box anywhere. I've searched for a bit on google and found nothing that will help me. If anyone has any idea or experience with this issue some advice would be greatly appreciated! Thanks!

Topic by bigjohn412   |  last reply

The RTC Routine of STM32

Good afternoon~everybody Please allow me to express my appreciation to you for taking time to read my post.I am a new hand in the electronics. And I met some troubles now.Could you give me some suggestions? Maybe my question is simple for you. The chip I used is STM32F100 and I use RTC routine from atom. But my program always shows: while (RCC_GetFlagStatus(RCC_FLAG_LSERDY) == RESET) What’s wrong? How to solve it? PS: This is data-sheet of STM32F100:  Please have a look if needed.

Topic by narne 

4-DCMotor Driver

Please help me to connect 4-DC-Motor-Driver-Module to arduino thank you

Topic by alisoud 

Any tips on disassembling bullet camera and relocating the lens module?

Hello!  I've been reading instructables for a while and now it's time to join and post a question. I've been finding nails in my driveway and want to catch who's doing this.  I've got a 4 channel security camera on it's way and have been thinking and researching ways to hide them.  Due to the 'clean' surfaces around my home, it's going to be tough to make the 2" diameter x 6" long bullet cameras blend in (so people don't vandalize/steal them).  I've spent hours searching how to camouflage cameras, so I know the 'typical' tricks. I'm thinking about making a fake gutter extension and hiding the camera in there (so it blends into my one story house), possible installing a gable vent on my garage and pointing a camera through that, or trying to mount a camera about 20' up a nearby tree.  My favorite idea is to take apart a bullet camera and move the camera lens module, which is much smaller than the whole camera housing, to a more discreet location. I've searched for a while but can't find anyone who has done this with an IP66 outdoor style camera.  I know I'm going to lose the IR LED's around the lens, and that's ok (I'll have 3 other cameras for night vision).  I think I can point the camera through a small knot hole in my privacy fence and be able to detect who has last walked by when the nails appear.  I might make a small weather proof enclosure to protect the lens module...I think I'm a good tinker-er so this isn't the problem. Has anyone hacked apart a security camera and moved the lens module (by extending the wires) to a remote location?  I know there are small cameras for sale, I know I can hide a camera in a bird house, etc...but I like to make things.  I'm just looking for advice/tips from someone who has done this.  When I search for 'hack apart a security camera' I get a bunch of 'hacking into a security system', or 'spy on your neighbors'...I don't want to do either of those.  I have great neighbors, I live in a corner house where a lot of people/kids walk...I just want to catch them.  Once I know who's doing it, I'll move the cameras to more visible locations (to deter others from doing anything else). Thanks for any help!

Topic by MountainBikeOutlaw   |  last reply

CNC auto level

I bought a 3 axis CNC machine from amazon, after putting it together with poor instructions, I had what looks to be a auto level prob wire. I am trying to figure out how and where to connect this single wire to the board? the IC in a atmega328p with Arduino loaded . I have some photos that maybe someone could tell me which pin to connect this to? thanks

Topic by DominickP4   |  last reply

Tethered wireless shooting with TP-Link router

Hi.... I've been following the instructable about wireless tethering using the TP-Link MR3040 portable router ( This is great and works very well. My problem is that the router in the instructable is now obsolete in the UK so I was wondering if anyone knows if the TP-Link MR3020 can be flashed with the same firmware? If not are there any other compatible portable routers on the market. I understand the firmware is based upon the OpenWRT firmware but that the author has added some additional scripts, if I can't find a suitable replacement router does anyone know what additional scrips have been added and if it's possible to add them to the OpenWRT 3020 firmware. Many thanks for any help.

Topic by kevdsn 

HOW TO: change USB plugs for 5 volts Jacks switch-Inputs (pics)

We have a several pair of carbon fibers pads, but what happens now all of them have a USB plugs that don;t fit with the receptive Jack Plug in 5 Volts Battery This batteries with the pads work to heat blanquet. We need help, or more than this a teacher! who tell us how to take out these USB plugs, how to join their cbables, and the how to add a plug in 5 Volts Jack. If is not clear please let me know Maria

Topic by Maria SoledadD   |  last reply

Help repair - identify part (diode)

Hi, Need help identifying this part. It is part of binary input stage, and is not working. I think it is diode, but not sure.  If You know what this part is please help. Thanks.

Topic by apofview   |  last reply


I am using a MOSFET with a remote control momentary switch to turn a 1.5v mini DIY motor, which in turn controls the movement of a tiny plastic mouth to simulate speaking.   My issue is this.....the MOSFET I have calls for DC 3v-5v powersupply.   When I use 3v, the battery drains very quickly.   I've found no such thing as a SMALL 5v battery in the U.S., so I switched to 6v and it works just fine, but I am worried I will damage the MOSFET.   Here is the spec info from the seller (we are using Version A - DC3v-DC5v).  Product Description 1. Working Voltage: A: DC3V-DC5V     B: DC3.5V-DC12V  Optional                                   2. Max Load: 1A (have better load less than 700ma)  3.  Working Frequency: 433.92MHz   Working Current / Quiescent current : 7ma/H  4. Frequency Deviation: more or less than 0.2MHz  5. Working temperature:  -20'C- +80'C  6. Receiving Sensitivity: ≥-110dBm  7. Output State: A: Input DC3V-DC5V  Output DC3V-DC5V 

Topic by croswords   |  last reply

Wind powered desktop PC, is it remotely possible?

So I was thinking up an idea this afternoon about how I could be more of a PC enthusiast, I came up with this idea: What if I could power a desktop grade PC on just the power supplied by a wind turbine (preferably that I had made myself), and batteries? My plan was to set up a (either or) BOINC Computer specifically for research, or something like a DNS/VPN server or failing that something like a NAS. Anyway, heres what I have been able to find so far in terms of wind turbines and power... It seems way over my head, especially the second link to the other question. Computer Specs that I had in mind: Intel i5 K series chip of sorts 8-16 GB of (presumably DDR3 memory) A motherboard, again, not sure exactly what but this can be chosen nearer the time, if it helps, something with around 2-4 PCI-e lanes for numerous GPUs. (This is NOT meant to be a gaming rig). A couple of GTX 760's I was having in mind, something older will do too. (This would be using the CUDA technology for accelerated processing) A Power supply that would fit the bill... 1000 watts? May be needed depending on the number of GPUs I have. I am so ignorantly unaware of how this would work.  Other things that I would need: - A wind turbine that was able to charge batteries during the day (for example) - Batteries - Some sort of converter (I think) to change whatever AC power there may be into DC. I think that is what I need,  Thanks in advance! slippers.

Topic by slippers_   |  last reply

Voltage rail identification on LCD PCB

I am testing the DC rails coming off an LCD TV PSU so i can convert the unit to run off an ATX PSU. i have managed to find (labelled on the board) 12v, 12v, NC, GND, GND, GND, ?, ?  the last two aren't  labelled. the two pins (when tested to GND) are giving me -12v, could this be right? I'm guessing by this point ill just have to use the 12v rails, GND and -12v from the ATX to get this powered?  what else could those last two pins be? 

Topic by andrewlapham2010 

sound effects modules

Hello!! I am planning several Halloween props that will benefit bigly from sound effects. For instance...I'm working on a mantel version of the demonic grandfather clock in Disney's Haunted Mansion. It would be awesome to have the sound of the ominous ticking, backed with a chime, that the "real" clock has. This could be an audio loop of just a few seconds. Some of the other parts of my scheme would be enhanced with short loops of sound effects or mood music...a minute or two at most. I don't have a background in electronics, but I can follow directions. Any advice on constructing a few, small sound effects modules? Thanks!!

Topic by Purple Chez   |  last reply

Instructables in SmartComputing

Instructables got a nice write-up in SmartComputing here: InJanuary 2008 Vol.19 Issue 1Page(s) 46-48 in print issueDIY Web SitesThink It, Learn It, Do It Instructables are step-by-step instructions that are accompanied by pictures and sometimes even video on anything and everything, from how to trigger green traffic lights to how to clean your sinuses to how to make a crossbow out of a pencil. This site is definitely all about having a good -- and sometimes mischievous -- time with all sorts of fun ideas. DIY projects from other sites can also be found here on occasion.Some of the most interesting categories are Art, Life, Offbeat, and Ride, although that by no means is the complete list. The Offbeat section is aptly named, so consider this fair warning: Some of the content there definitely meanders off the usual path.Members submit their ideas with visual aids and step-by-step instructions, and others can comment on their creations, ask questions, or make suggestions for improvements. It is free to sign up for an account; in addition to the aforementioned privileges, members can print instructions, post a question on the forum, message other members privately, and receive the weekly newsletter.Instructables also features contests, such as Launch It!, wherein contestants offer their best projectile creation. There is a new contest theme every so often, sometimes reflecting the current holiday season. Contests such as these bring out some of the wildest, most interesting designs you can find on the site.More news articles about Instructables here.

Topic by ewilhelm   |  last reply

laptop screen becomes digital picture frame

I am wondering about the possibility of turning the screen of an unused laptop (or another flat screen monitor) into a digital picture frame. I don't have a background in electronics but am pretty good with directions. Audio would be a nice bonus, but is not a necessity.   Thanks, everyone!!!

Topic by Purple Chez   |  last reply

No Replies from Authors

Dear Instructables Management, There is an all too common phenomenon of authors who publish their projects and then NEVER reply back to enquirers. I`ve sent a message to without any reply from her.  I need to understand something from her project.  So how do I solve this. In another case a person has been waiting for 10 (TEN) MONTHS and still no reply. It just seems to me that authors are looking for the limelight and then disappear.  NOT ACCEPTABLE. Regards, HendrikB7

Topic by HendrikB7   |  last reply

Cost of common DYI engineering project?

Hi there, I am inexperienced in engineering and building things in general, but I am trying to start a tech company anyway. I am currently in the process of determining the budget cost of building a prototype for various designs of ideas. So I am wondering if you can tell me how much commonly used tools and materials of a DIY mechanical/electrical engineering project might cost. If you don't know because estimates can vary, then tell me from your personal experience how much your list of tools and materials costed you on various projects that you've done. Thank you!

Topic by DIYDun 

Run AC device on DC: An idea, could it work?

I need to run an AC powered audio mixer on DC current from a battery. Yes, I could buy a power inverter, but I want to make the system the simplest I can, and I also have an old small mixer I'm not using (that I can experiment on). I'm self taught on electronics, so please tell me if there's any inaccuracies in the following lines: My idea is to find where in the circuit AC gets converted into DC, and then at that point feed the DC current from my battery. I think that point would be right after the bridge rectifier. So, in shot: Can I connect de dc output from my baterry to the end of my audio mixer bridge rectifier? Thank you!!

Topic by FrancoMolina   |  last reply

logging ESP8266 data of(BMP180+DHT22+Ublox GPS Neo 6m +hc04 ultrasonic sensor)

Hi instructables , i'm just starter in this filed i just need Sketch for logging ESP8266 data of(BMP180+DHT22+Ublox GPS Neo 6m +hc04 ultrasonic sensor) all data in separeted files  i found in Net GPS neo logging but for the authers no ..please if someone can help me i will be very thankful 

Topic by Slash09   |  last reply

Piping audio from mpg321 to PiFmRds

I was working on a little project that turns my Raspberry Pi 2 into a FM transmitter. The goal is to make it completely headless, having it start up immediately on boot, without any external computers or peripherals. Now, I have tried this following command: mpg321 --random /home/pi/music/ -  | sudo /home/pi/PiFmRds/src/pi_fm_rds -freq 95.5 -audio - The first command tells it to randomize and play the music. Then the directory it is in. Then there is the pipe, followed by the command to start PiFmRds, on the frequency of 95.5 FM. And finally, to take in audio from a pipe. But I get this: High Performance MPEG 1.0/2.0/2.5 Audio Player for Layer 1, 2, and 3. Version 0.3.2-1 (2012/03/25). Written and copyrights by Joe Drew, now maintained by Nanakos Chrysostomos and others. Uses code from various people. See 'README' for more! THIS SOFTWARE COMES WITH ABSOLUTELY NO WARRANTY! USE AT YOUR OWN RISK! Playing MPEG stream from - ... Using mbox device /dev/vcio. Allocating physical memory: size = 3403776     mem_ref = 5     bus_addr = fd812000     virt_addr = 0x768c8000 ppm corr is 0.0000, divider is 1096.4912 (1096 + 2012*2^-12) [nominal 1096.4912]. It's not showing any errors, but it doesn't tell me a whole lot. Additionally, the radio I have tuned to the frequency that I set does not play anything, though it is silent, suggesting that it is transmitting. Is there some obvious error to what I am doing, or do I need to take a different approach? Or perhaps I just need to look into the documentation of mpg321 some more?

Topic by Dashing Rainbow Dash 

Repair of Electronic choke for 4'tube light

I tried to repair two electronic chokes for 4' fluorescent tubes but cdn't succeed. If any one kindly help me by providing a step by step guide with the test voltages etc. at important points in the circuit, I will be ever grateful. The following things have been already done/checked. Physical checking of any defect/damage/burning marks etc., DC voltage after rectification is OK, Filter capacitor (DC voltage  after rectification ) is checked OK, Other electrolytic capacitors chked to be OK, one of the 13005 transistors was found defective - changed with a new one, but no result. Voltages at the transistor terminals seem to be OK.. May pls write to me directly. B.N.Bhattacharya

Topic by bnber3451   |  last reply

DESIGN tutorials!

I've been looking around, and it seems like generally instructables users are not web/graphics designers. There needs to be a section for the design tutorials!!! Anyways when my schedule frees up in the future, I'll add some flash and dreamweaver tutorials... otherwise there is a major lacking of web DIY instructables! what you guys think? Dont you guys wanna learn how to DIY (design it yourself)? I am talkin about design here, not art.

Topic by tekness   |  last reply

Idea DC-DC converter step up from usual power bank as external battery for nikon DSLR

Can anybody build a circuit to convert the 5v-2.1A to 8.4v-2.5 to be able to power on the DSLR camera USB output 5V*2.1A=10.5W Camera input 8.4V*2.5A=21W The idea inspired from ifootage Electric Ray E1  ,I don't believe in would power on my DSLR nikon D7100 probably, plus it's too expensive for me 

Topic by assem555   |  last reply

Why to use RF directional couplers in some measurements and control processes ?

I am an electronic engineer in the field of RF directional couplers, but I am puzzled about this question, why to use RF directional couplers in some measurements and control processes ? Today I come to this forum to turn to you to discuss my understandings are appropriate. Here are my personal understandings: RF radio frequency is referred to as RF current, it is a high frequency AC change electromagnetic wave short. Less than 1000 times per second changes in alternating current called low frequency current, more than 10000 times called high frequency current, and radio frequency is such a high frequency current. RF technology in the field of wireless communications with a wide range of irreplaceable role. In the electronics theory, the current flows through the conductor, the conductor will form a magnetic field around; alternating current through the conductor, the conductor will form an alternating electromagnetic field, known as electromagnetic waves. When the electromagnetic wave frequency is lower than 100khz, the electromagnetic wave will be absorbed by the surface, can not form an effective transmission, but the electromagnetic wave frequency is higher than 100khz, the electromagnetic wave can be spread in the air, and the outer edge of the ionospheric reflection, the formation of long-distance transmission capacity (Analog or digital) with high-frequency current modulation (amplitude modulation or FM), the formation of radio frequency signals, through the antenna to launch into the air, the radio frequency of the high-frequency electromagnetic waves.  Long-range radio frequency signal received after the anti-modulation, reduced to the electrical information source, this process is called wireless transmission. Wireless transmission developed for nearly two hundred years, forming a large number of users and product groups, but because of climate change and the impact of surface obstacles, can not transmit the perfect information. Modern human invention of the cheap high-frequency transmission cable (radio frequency line), in order to pursue the perfect quality of information transmission, taking into account the original wireless devices, wireless cable transmission began to pop. Resulting in the concept of radio frequency transmission. If your information source through the secondary modulation, with the cable to the opposite end, the opposite side with anti-modulation of the information source after the re-application, no matter how low frequency, but also radio frequency transmission, if there is no modulation anti-modulation process, The information source is transmitted directly to the opposite end of the cable, no matter how high the frequency, are the general cable transmission. SI --- Signal Integrity Signal Integrity PI --- Power Integrity Power Integrity emc --- electromagnetic compatibility Electromagnetic Compatibility rf - radio frequency RF emc = emi + ems EMI = Conduction + Radiation Emission SI: The Fourier transform shows that the higher the signal rises, the higher the amplitude of the higher harmonics. The MAXWELL equations see that these alternating harmonics produce alternating current at the adjacent line. And even through the space parasitic capacitance directly to another conductor, so these high harmonics is caused by radiation interference (emission) of the main factors; (that the simple point is that the signal rise faster, the more complete the signal, the better the signal quality, But for emi bad) . PI: PCB exists on the number \ \ analog area, high frequency \ 'low frequency region and other different areas and planes, if the partition is not easy to interfere with each other, that is, conduction conduction (conduction). Ps: Excuse me if I was wrong in words or expressions as I am a green hand in the field of RF directional couplers. I need continual learnings. What is your idea ? Do you agree with my ideas ? Any of your ideas would be highly appreciated. May someone would like to help ? thanks in advance.

Topic by maryzhu   |  last reply

Let us assemble power distribution switches at home together.

I am an electronic engineer in the field of power distribution switches. In recent days, I am prepared to make a project for power distribution switches at home together.  The project begins now: Home decoration, the concern of hydropower indispensable. The laying of the home circuit is a crucial link, the home distribution box installation involves the safety of home appliances. Therefore, I specifically summarise the home distribution box installation knowledge, as well as home distribution box wiring diagram to make the relevant finishing, for everyone to take precautions, the home distribution box has a clear understanding. Home distribution switch installation points 1, Household distribution switch sub-metal shell and plastic shell two, there are two kinds of mounted and concealed, the box must be intact. 2, The household distribution switch of the cabinet wiring assembly should be set up to zero line, to protect the ground wire, phase line, and to be intact, with good insulation. 3, The installation of air switch seat should be clean and there is enough space, should be installed in the dry, ventilated parts, and no obstruction, easy to use. Never install the distribution box in the box to prevent fire. 4, The household distribution switch should not be installed too high, the general installation of the elevation of 1.8 meters, in order to operate; into the distribution switch of the electric tube must be fixed with a lock nut. 5, If the household distribution switch to be open, the edge of the hole to be smooth, smooth, distribution box buried in the wall should be vertical, horizontal, edge left 5 to 6 mm gap, distribution box wiring Should be rules, neat, the terminal screws must be tightened. 6, The loop into the line must be sufficient length, no joints, after installation marked the name of the use of the circuit, the installation of household distribution box to be completed after the removal of the distribution box residue. How to assemble power distribution switches at home ? 1, The installation of electrical box, distribution box installed on the wall, should be used bolts (expansion bolts) fixed, bolt length is generally buried depth (75 ~ 150mm), the thickness of the box floor, nuts and washers Of the sum of the thickness, plus about 5mm of the "margin". For smaller distribution boxes, it is also possible to embed a good brick at the installation site (in the form of a distribution box or a panel mounting hole) and then use wood screws to secure the distribution box or power distribution board. 2, Dark assembly distribution box, distribution box embedded in the wall installation, in the wall when the hole should be reserved than the length and width of the distribution box about 20mm, the depth of the distribution of the thickness of the distribution box with the wall Plaster thickness. In the masonry distribution box, the box and the wall filled with concrete can be fixed to the box live 3, The distribution box should be installed firmly, horizontal and vertical, vertical deviation should not be greater than 3mm; concealed, the distribution box should be around the gap, the edge of the panel should be close to the wall, the box and the building, Part should be coated with anti-corrosion paint. 4, The distribution box installed in the spiral fuse, the power cord should be connected to the middle of the terminal contact, the load line should be connected to the threaded terminal. In this way, in the loading and unloading fuse will not be electric shock. Porcelain plug-in fuses should be mounted vertically. 5, The distribution box of AC, DC or different voltage levels of power, should have a clear sign. Lighting line, should be set to zero line (N line) and protect the zero line (PE line) bus, zero line and protection of the zero line should be connected to the bus, not twisted, should be numbered. 6, The wire leads to the panel, the panel line hole should be smooth without burrs, metal panels should be installed insulation protective cover. Metal shell distribution box shell must be reliable grounding (then zero). Ps: Excuse me if I was wrong in words or expressions as I am a green hand in the field of power distribution switches. I need continual learnings. What is your idea ? Do you agree with my ideas ? Any of your ideas would be highly appreciated. May someone would like to help ? thanks in advance.

Topic by maryzhu   |  last reply

About RN-42 bluetooth (with two arduino MICRO and one laptop)

Hi, there. I have a question about RN-42 bluetooth module. I want to make a bluetooth HID device (keyboard and mouse) and ,because of my direction of team project, it has two pieces. One arduino MICRO (using RN-42) is going to be master and the other MICRO (using HC-05) is going to be slave. Actually their roles can be changed! The goal is to connect RN-42 to my laptop while RN-42 is also connected to HC-05 and use this as a bluetooth keyboard. Now, Is it possible that RN-42 module has multiple connections?

Topic by 태현김3   |  last reply

D3CRYPT3D won SXSW Interactive Innovation Award for Privacy & Security

Hey everyone! For a long time, being a modeler and working in the industry, I have always felt that Modelers get the short end of the stick.  Things get re textured, models get hijacked and studios just kind of store models and stock pile them up. Some people will even resell models that don't belong to them. I used to see it all the time. Well, my crew and I came out with a software that enables you to share and collaborate on your 3D files securely. We won the SXSW Innovation Award for Privacy & Security last month and just released our beta this week.  We would love for you all to try it out and give us your feedback so that we can make the best product possible.  If you are interested, here is the link to download - Thank you!

Topic by D3CRYPT3D 

Crazy Circuits Kickstarter and Giveaway

I though I might post about this new project we've put together. Crazy Circuits Kickstarter We've developed a LEGO based electronics system.  More or less, parts on circuit boards with big holes.  It works great for creating LEGO robotics and electronics projects.  From simple to advanced. We'll be posting several instructables on how to use these, as well as projects you can build with them.  (Or without them.  They're just simple parts on our custom PCBs.) We're also giving away several 1 month subscriptions on our Facebook page.  

Topic by BrownDogGadgets 

Making a Wireless Security Camera

Managed to pick up a Swann swpro-642cam night vision security camera. No idea if it works, haven't tested it. But I would like to turn it into a wireless security camera for home. Assuming I would need a transmitter, but I'm not sure what kind. I would prefer to have it so I can just pop it up on my computer or phone, so could I avoid using a receiver and can it be recorded on my laptop as well?

Topic by 4DIYers   |  last reply

Will a SSR work with a PWM signal?

Hey guys gotta quick question: I need to be able to cut a PWM signal from a motor for a project. I'm currently using mechanical relays but I'm curious, will a solid state relay work? I know there are easier ways to do this but for right now I'm on a clock and I just want to  know whether a SSR will work for cutting a PWM signal.  Thanks guys!

Topic by HavocRC   |  last reply

Interesting TAP handle tech question \ quest.

Here's a weird one for  you guys. I recently bought a Beer tap handle and noticed that it had an insert that had some LEDs on it. Cool. The problem is that the LEDs don't light (beyond a tiny SMD red LED heartbeat). I found a small button that when depressed seems to trigger a test. Bright white LEDs on the top and bottom flash to illumnnate the top of the tap (either a clear baseball or FIFA tap topper) as well as the body. It's hollow plastic so it briefly glows. The problem is that I can't figure out how to light the things beyond the test (for which you have to remove it from the handle). The guy who sold it to me said they've sold lots like this and could never figure it out. I figured light sensor? nope. Tilt sensor so it'll flash when you pour a beer. Nope. I broke out  my loupe and noticed a funky thing on the circuit board that looked like it had an antenna. It was an Anaren A1101R09A. This thing is a radio tranceiver!  That tells me there was a remote with it that was lost in the few days after they bar got their new tap handle. Does that sound right? If so I was wondering where I could get or build another. I could put together some other LED solution, but I'd love to get this to work. HEre's a pic of the tap handle and the insert laying on it's side. The right side is the up side with the transceiver. It's blue if you look closely. Not sure I'll get a solution, but there's some clever people here, so you never know. Thanks for reading.

Topic by mcgary911   |  last reply

How to Make a Constant Current Lithium Ion Charger

Hi Guys! I have a bunch of 18650 lithium ion batteries that can handle a charge rate of 5C. Each one is 3,000 milli-amp hours, and I would like to build a charger for them as my project. I understand the mechanics of charging lithium ion batteries, and that they need to be charged at a constant current up until that current reaches 4.2 volts, than switch over to constant voltage. The constant voltage charging makes up about 20% of the battery capacity, and I am willing to forgo that amount. What I am trying to build is a constant current charger for it that would  charge at a current of 1C, and shut off when it reaches 4.2 volts, and I would like some help as to how I would do this. I was thinking that I would have some sort of current source that supplied 3 amps and then have a relay that would shut off the current as soon as a voltage detector reached 4.2. I do not know much about current sources, so I am asking here for some help. Thank You for Your Help!

Topic by merlinj   |  last reply

Another car that runs on fresh air.

Here's another chap with a car that runs on compressed air.He's got more potential than past attempts, though - F1 engineering background, large backer, neat trick for extending range.The video and Previous BBC "airing"Canadian news articleCritical article from Oil Drum (Australian energy site)Oil Drum: part 2Air Car siteEDIT (MORE REFERENCES)Another BBC articleMDI Engineering site (they make the engines)Tata Motors (who plan to build the car)

Topic by Kiteman   |  last reply

Voltage help

Hello I am new to electronics I am having trouble designing a circuit that lowers VDC as ground resistance increases and raises as ground decreases every circuit I've built works backwards. I am working with 5vdc any help would be much appreciated thanks

Topic by Ed69   |  last reply

DTMF Generator with Arduino

Hello mate, I have telephone with only receiver and no keypad. So, i need to generate DTMF tones to dial the number. Is it possible for me to generate a DTMF tone generator by programming arduino with the frequencies and attaching speaker to it? Also, how can i club two tones which are required to be sent at a single moment? Thank You. 

Topic by anuragkanase   |  last reply