PLEASE HELP!!!!!! Moisture sensor plan not working - or is it me :-(

Can anybody PLEASE help, I am in the UK and eager to grow melons next spring. I need to know when the roots of the tub need water so decided to make a moisture sensor. I found a ‘plan’ online, bought about £20 of components (I need two sensors) and have spent all afternoon TRYING to get it to work. One was connected via a circuit board and the other without. Neither work, the LED comes on on both versions but does not go out when the terminal probes are put in water, as they would when the plant roots are moist. i enclose the original internet plan and a (poor) picture of my ‘‘air connection’ version....should this plan work? And if so, why isn’t it? thanks in anticipation

Topic by TN1946   |  last reply

Hmr software

When I post programs using hsm software my haas milling machine alarms out. Any suggestions on how to fix this?

Topic by jerrybudzinski   |  last reply

Led Clock Feasibility - my first arduino project

Hi guys and good morning all from a total newbie to this world. The aim of this post is to ask you guys if i'm going the right direction to master the knowledge to build my project. To cut a long story short, my plan is to build a clock mixing the old style design of reclaimed pallets with a touch of modernity using LEDs to mark hours , minutes and seconds. The aim is to keep all the lights ON once the given time has passed. To be clearer, if the minutes are "18" i would like all the previous leds (0 to 17) to be all on. I'm pretty sure that the knowledge to build this resides in mastering Charlieplexing and Shift Registering (please correct me if i'm wrong). So at this point in time, i know what i have to "study" to give life to my project the way it's designed in my mind. I've already seen some clocks working this way, hence i'm pretty sure it can be done (happy days!). Point is that i've only seen clocks where this design is achieved with only 1 row of leds. My aim is to swith on 4 rows at any Tn time. So, for the minutes, once it reaches 59, i should have 59 * 4 = 236 LEDs ON simultaneously (for the minutes only... plus N for the hours). Can anyone point me to the right knowledge to be mastered to achieve this? I'm assuming is a problem of sustainable voltage (resistors, power supplies etc etc) leds in paralel/serial; multiple shift registers and so on so forth... I'm attaching a small mock-up to be understandable on what i would like to achieve (it's based on the first 5 minutes of each hour). I've marked "Ok" the first row, meaning that since i've seen something similar, i'm confident in knowing what needs to be mastered to achieve that result. The "?" refers to what i haven't been able to understand if it's achievable or not (row 2, 3 and 4). Would it be advisable to build a Matrix for each of the 4 row (with N 8-bit microcontroller such as SN74HC595, for each row) , or can be achieved with a "simple" 4 X 60 matrix? Thanks a lot in advance to everyone "wasting" their time to give a helping hand! Seeya! Ivano

Topic by IvanoArduino   |  last reply

Single Piston Air engine

Hi all, need help/ advice in designing a single piston air engine, It is part of a mechanical engineering course I am currently studying, the only parameters i was given are - Single cylinder with vertically displaced piston with rotation of the input shaft on a horizontal axis - free standing with an operating envelope of 300mm x 300mm x 300mm - accommodate a nominal piston diameter of 20mm - engine capacity of 6.0cc / 6000mm (cubed) Any help would be greatly appreciated Thanks in advance

Topic by DavidO242   |  last reply

Alternative to keyboard

On top is a joystick like an NES joystick. It registers 8 different directions: up, down, left, right, and the in-betweens of those and is controlled by the thumb. Then there are 4 buttons, one for each finger. The joystick replaces the trackpad of a laptop and hopefully is also 'clickable'  to act as a 'left click button. I'm not sure what would do the right click button. Combinations of button presses and joystick directions would replace the keys on a keyboard. I only have the use of my right hand. I initially thought of this as a device for handicapped people like myself, but it would also be good for people lying in bed. The concept maybe could be made into a cell phone case with physical buttons that would allow people to text without looking at their phones. The device is a lot like the nintendo wi remote, but not quite. Maybe a wii remote could be hacked to make a prototype. I wouldn't know how to do that and I wouldn't know how to program it, that's why I'm posting, to see if someone could tell me what kind of skills/knowledge would be needed to make this idea happen. Any suggestions or offers to help are welcome. Thank you!

Topic by avocadostains   |  last reply

Musical Parrot Toy

Serious request... my Parrot (African Grey) loves music. I would like to buy/build 'Parrot-proof' musical 'instrument/s' device/s that he can play, perhaps triggered by either percussive impulses from his beak and/or his vocal range. This would help him remain stimulated when I am out. All genuine replies welcome... :) The closest thing available is this, but it isn't very versatile (only pre set sounds) + not very musical

Topic by ParrotFX   |  last reply

Post your best jokes here!!!

Whoever posts the best damn joke there is (judged by me) will win a free patch.(not a huge prize, but I hope you still try) Note: The jokes should be appropriate, with no bad language. (8+) The comp has been won! ilpug won with his hilarious panda joke! I hope you all enjoyed each others jokes!

Topic by HMice   |  last reply


Ok So I tried to get into instructables today but instead got this crazy robot game. As you can see my high score is 0, 1 can you beat my score?

Topic by liquidhandwash   |  last reply

Am I the first to ask a question ?

LOOOOOL Checked the recent answers and got this picture... Seems our code monkeys are doing overtime. I really hope we did not loose all the answere here ;)

Topic by Downunder35m   |  last reply

I keep feeling like I'm out of place in group calls

Whenever I get into a group call on Discord or something, I just get the nagging feeling that I don't belong in some way. Like, I may feel that people aren't acknowledging my presence, or that they don't really care to talk towards me. Am I the only one who keeps feeling something like this, in these situations? And, what can I do about it?

Topic by Dashing Rainbow Dash   |  last reply

judging(how much TIME JUDGING takes)

Does any one know how much time judging takes when voting is finished 

Topic by hadi141   |  last reply

gift exchange

Is anyone interested in doing a gift exchange? like exchanging random thingamajigs you've built or something.

Topic by bravoechonovember1   |  last reply

Arduino D1 WeMos with LabView

Hey, I want to build a project that gets information from the "Temp102" sensor connected to the D1 WeMos Board. This board sends the information received from the sensor via WiFi. I want this information that sends to the computer that has the LabView software and it will display the temperature in a termometer. I have a program that I found in one of the sites that does what I want but with one problem! The program is written for module Esp8266, which is connected to board Arduino Uno and therefore has different classics. I need help converting the classics of module ESP8266 to relevant classes for Board D1 WeMos (This board has ESP8266 but it is built-in so there is no need to set it up in the program). It's important to note that I tried to change it and make a "mix" but without success. I would be happy if someone could check in the program what should be changed, which orders should be replaced? (I believe it's 2 minutes work for anyone who knows) Thank you very much for your help ! I appreciate you very much !! I attached the programs (for arduino and for labview).

Topic by OriaA   |  last reply

Circuit to flash a bank of lights

I have a bank of 30 x 6 volt lamps in an old computer console and I am trying to find a circuit to flash them in a random pattern. Ideally the lamps will be driven from a chip rather than individual transistors. I'm perfectly capable of building the circuit, but not designing it. Can anyone point me in the right direction please? Thank you.

Topic by nickpb   |  last reply

Vacuum forming heat source

Hi! I am planning to build a vacuum forming machine that does not use a seperate oven to heat the plastic. For my 3D printing hobby I have come across many heated beds, also some on 230v. Could something like this ( with a heat sink be used for such an application? Thanks!

Topic by ttreurniet   |  last reply

Li-Ion battery pack

Hi, I have 4x PANASONIC CGR18650CG LI-ION BATTERY 2250mAh 3.7v.  I have connected them in series and it gives around 14v. My internet router is working on 12v 500mA. Is this battery pack too much for that router? I was thinking to use that battery pack as backup for my router when there is no electric power, because it's winter and every few days there are problems with power. Thanks!

Topic by AdvanŽ   |  last reply

Instructables needs a Fitness category

I was browsing and thought that we really need a fitness category or contest because instructables is really about making stuff and and a huge part of fitness is making stuff to maintain health.

Topic by jcsuperman   |  last reply

Re-programming a Microchip RN2903 Mote - DM164139 with Arduino IDE

I am interested in creating a pair of 915MHz radios with Microchip'sRN2903 Motes to send basic messages to each other.  Can they be re-programmed with Arduino IDE?

Topic by Do_Not_Give_Up   |  last reply

How to Clean Silt from Dug Round Water Wells Used by 3-4 Billion People on Planet?

This is a clam shell bucket, from an old toy crane. I am taking this to a machine shop, welder, had having them make it 18 inches wide. It would be used only with rope, no block and tackle.  Problem: As best I can surmise, about 1-10 percent of hand dug, round water wells used by around 4 billion people on the planet are full of silt, dirty, and old plastic jugs used to pull the water up from well. As the silt rises in the well, the wells slowly become too dirty, or the locals need to pull the water out in buckets, then allow the silt water to settle. It is way to expensive for people who earn 10 USD per day to pay people with pumps to drain the wells. I want to create a 1-2 man powered clamshell bucket system to clean these wells.  What is the best way to make a method to clean a dug well? How much would the steel, rebar cost? Labor is 10 dollars per day in central American, South America, Africa etc. Thanks for help, I will take the finished bucket to Lome, Togo West Africa to test, and modify, iterate. Andy Lee Graham of

Topic by hobotraveler   |  last reply

CNC Laser Printer

Looking for someone to help me build a Laser printer. I want to go A0 size. Use Photographic negative, that is to use a developer and fixer liquid once the image is done. The image has to be B&W photographically with a sharp image quality. What sort of laser would allow me to have a high resolution? Thanks jag2x

Topic by jag2x   |  last reply

Motor assisted pedal powered rail rider

I am trying to build a 2 person human powered Vehicle that is also motor assisted, I need a way 2 people can pedal at diffrent speeds and drive the same axle. What I think I need is some sort of differential gearbox. What Ii need to know is: Is there is a differential that can take 2 different input speeds and have one output? If it did and I also pushed it with a motor would the wheels spinning feed back though the gearbox and send the pedals spinning like crazy? Any help or advice people can offer would be great.

Topic by BillP55   |  last reply

Favorite Sport/Team

What is your Favorite Sport, and your favorite team?

Topic by shadowninja31   |  last reply

What do you love about Instructables?

I am a huge fan of Instructables and am curious why other people enjoy it so much. I believe it is important to tell others, how their hard work has been appreciated. Most of the time we tell people what we don't like about something. I have been a member of other sites like utube and blogs but I have stuck with Instructables because it has offered me an outlet to share what I make and connect with others. I like the fact that if we publish a good Instructable we get featured and that is a great way to get exposure. Their contest can be challenging as well as fun. I believe they try very hard to listen to their readers and authors. It is not just the Instructables team that make this such a great place but our readers are important as well. I have found most of the people here are kind and respectful. Please share your positive comments with me about why you love Instructables. Thanks for sharing your thoughts! Sunshiine   

Topic by sunshiine   |  last reply

400 Volts 3 phase to 240 Volts Single phase Motor

Hello we bought a cutter from Europe.  It came with 400V 0.75W  3 phase  motor. The motor has leads W2, U2, V2 U1,V1, W1 To convert to the 240 V single phase we jumped (W2,U1), (U2, V1), (V2,W1). We also put 50uf capacitor between (W2,U1), and (V2,W1) .See attached pictures. However the motor starts and spins for about 5mins then it trips the breaker. The motor heats up . Voltage reading Between (W2,U1) and (U2, V1) =240v Between (W2,U1) and (V2,W1) = 370v Between (U2, V1) and (V2,W1) =240v We thought  (W2,U1) and (V2,W1) = 370v was little high. Also the resistance between winding W1W2 is 36 ohms, U1U2 20 ohms, V1V2 20ohms Can someone help? I will really appreciate you help

Topic by ngong123   |  last reply

Arduino codes

Good evening Sir, Madam, I am currently attempting to build a circuit for a college module that would use vibration data from a dc motor then send it to a microprocessor before transferring the data via Bluetooth to a pc. I have trawled through numerous sites for the correct components to use but. My question is this. Is there a Arduino code that would enable this idea to be successful? Having never written a code I am somewhat stumped and stressed out to the max. I would be grateful of any help or advice you can offer, Thank you in advance for your time over this, Best regards Mark sheldon

Topic by Shaggy74   |  last reply

Web design & development series

Hi, I am web designer & developer form Nederland. I've been looking around here for some time and it seems like there are not many series that cover everthing about how to design and then develop a website. I thought it would be awsome to create a instructsble serie that let's someone develop there own website in pure HTML & CSS. So I have a couple of ideas. - explaining the basics of flat design (todays standard in web design) - creating a website in pure html & css from the ground up - creating a compleet wordpress theme - much more If you like one of the above ideas or if you have one of your own, please let me know. Thanks for reading. And let me know what you think! Greetings from Holland.

Topic by Kevin Tipker   |  last reply

need help with coding for the interactive table designed by grahmaustin

I just cant get it to compile here is the code /***                   PIN ASSIGNMENTS ON ATMEGA48 PC6 (PCINT14/RESET)            PC5 (ADC5/SCL/PCINT13)            // I2C Clock input PC4 (ADC4/SDA/PCINT12)            // I2C Data input PC3 (ADC3/PCINT11)                    //Sensor 4 IR Receiver PC2 (ADC2/PCINT10)                    //Sensor 3 IR Receiver PC1 (ADC1/PCINT9)                      //Sensor 2 IR Receiver PC0 (ADC0/PCINT8)                      //Sensor 1 IR Receiver PB7 (PCINT7/XTAL2/TOSC2)         //IR 4 Trigger PB6 (PCINT6/XTAL1/TOSC1)         //IR 3 Trigger PB5 (SCK/PCINT5)                           //IR 2 Trigger PB4 (MISO/PCINT4)                        //IR 1 Trigger PB3 (MOSI/OC2A/PCINT3)            //PWM 3 PB2 (SS/OC1B/PCINT2)           PB1 (OC1A/PCINT1)               PB0 (PCINT0/CLKO/ICP1)           PD0 (PCINT16/RXD)                PD1 (PCINT17/TXD)                PD2 (PCINT18/INT0)                PD3 (PCINT19/OC2B/INT1)         //PWM 4 PD4 (PCINT20/XCK/T0)            PD5 (PCINT21/OC0B/T1)             //PWM 2 PD6 (PCINT22/OC0A/AIN0)         //PWM 1 PD7 (PCINT23/AIN1)             ***/ #define IR_1_ON PORTB |= (1<<4) #define IR_2_ON PORTB |= (1<<5) #define IR_3_ON PORTB |= (1<<6) #define IR_4_ON PORTB |= (1<<7) #define IR_1_OFF PORTB &= ~(1<<4) #define IR_2_OFF PORTB &= ~(1<<5) #define IR_3_OFF PORTB &= ~(1<<6) #define IR_4_OFF PORTB &= ~(1<<7) #define PWM1 6                    //PORTD        PWM pin assignments #define PWM2 5                    //PORTD #define PWM3 3                    //PORTB #define PWM4 3                    //PORTD #define F_CPU 8000000UL #include #include #include //#include /****Function Declarations****/ int ADC_read(void); void A2D_Channel_Select(unsigned char channel); void Init_ADC(void); void Init_Timer0(void); void Init_Timer1(void); void Init_Timer2(void); void Delay(void); void Calibrate_Sensors(void); //void Init_I2C_Slave_Rx(void); /****Global Variable Declarations****/ volatile char Sensor_Values_Updated = 0;                   volatile char Timer1_Overflow = 0; volatile unsigned char channel = 0; volatile int Amb_Sensor_1 = 0, Amb_Sensor_2 = 0, Amb_Sensor_3 = 0, Amb_Sensor_4 = 0; volatile int Sensor_1 = 0, Sensor_2 = 0, Sensor_3 = 0, Sensor_4 = 0; volatile int Initial_1 = 0, Initial_2 = 0, Initial_3 = 0, Initial_4 = 0; volatile int New_PWM1 = 0, New_PWM2 = 0, New_PWM3 = 0, New_PWM4 = 0;               volatile int Old_PWM1 = 0, Old_PWM2 = 0, Old_PWM3 = 0, Old_PWM4 = 0; unsigned char buffer = 8; int main(void) {  DDRB = 0xff;     //make sure IR emitters are turned off, and PWM 3     PORTB &= ~((1 << 7)|(1 << 6)|(1 << 5)|(1 << 4)|(1 << 3));                   DDRC = 0x00;                    //make PORT C inputs        DDRD = 0xff;     PORTD = 0x00;                    //set all of PORT D low. ensures            Init_ADC();     sei();        Calibrate_Sensors();     PORTD |= (1 << PWM1);            //blink to indicate end of Calibration     _delay_ms(600);     PORTD &= ~(1 << PWM1);     Init_Timer0();     Init_Timer2();     //Init_I2C_Slave_Rx();     while(1)         {             //do something?             //. . .         } } ISR(TIMER1_OVF_vect)      {         Timer1_Overflow++;            //increment timer overflow variable                switch(Timer1_Overflow)             {                 case 1:                                       A2D_Channel_Select(0);                            //select ADC channel 0                     Amb_Sensor_1 = ADC_read();                 //take ambient IR sensor reading                     IR_1_ON;                                                        //turn on IR 1 LED, PORTB |= (1<<4)                     Delay();                                                           //delay for the IR receiver to settle                     Sensor_1 = ADC_read();                            //take active ADC reading of IR receiver                     IR_1_OFF;                                                       //turn off IR 1 LED                       New_PWM1 = (Sensor_1 - Amb_Sensor_1) - Initial_1;    //condition readings                     if(New_PWM1 <= 0)    { New_PWM1 = 0; }                //prevent negative numbers                       New_PWM1 = ((7*Old_PWM1)>>3) + (New_PWM1>>3);                           if(OCR0A >= 1)    {DDRD |= (1 << PWM1);}                     else { DDRD &= ~(1 << PWM1); }                        //turn off LEDs completely                       New_PWM1 <<= 2;                                                                          if(New_PWM1 > 255)    { New_PWM1 = 255; }                     OCR0A = New_PWM1;                     New_PWM1 >>= 2;                         /*****        //Trigger sequence                     if(New_PWM1 > Initial_1)                         {                             DDRD |= (1 << PWM1);                             if(OCR0A < 255)                                   {                                     OCR0A += (255 - OCR0A)>>2 ;                                     //OCR0A++;                                 }                             if (New_PWM1 < (Initial_1 + 8))                                 {                                     Initial_1 = ((7*Initial_1)>>3) + (New_PWM1>>3);                                 }                         }                     else if(New_PWM1 < Initial_1)                         {                             if(OCR0A > 0)                                   {                                     OCR0A -= (OCR0A >> 4)+1;                                     //OCR0A--;                                 }                             else if(OCR0A <= 0)                                   {                                     DDRD &= ~(1 << PWM1);                                 }                         }                          *****/                       Old_PWM1 = New_PWM1;                                           break;                        case 2:                     A2D_Channel_Select(1);                            //select ADC channel 1                     Amb_Sensor_2 = ADC_read();                     IR_2_ON;                                        //turn on IR 2 LED, PORTB |= (1<<5)                     Delay();                                        //delay for the IR receiver to settle                     Sensor_2 = ADC_read();                            //take ADC reading                     IR_2_OFF;                                        //turn off IR 2 LED                       New_PWM2 = (Sensor_2 - Amb_Sensor_2) - Initial_2;                     if(New_PWM2 < 0)    { New_PWM2 = 0; }                                        New_PWM2 = ((7*Old_PWM2)>>3) + (New_PWM2>>3);                     if(OCR0B >= 1)    {DDRD |= (1 << PWM2);}                     else { DDRD &= ~(1 << PWM2); }                     New_PWM2 <<= 2;                     if(New_PWM2 > 255)    { New_PWM2 = 255; }                     OCR0B = New_PWM2;                     New_PWM2 >>= 2;                 /*                     if(New_PWM2 > Initial_2)                         {                             DDRD |= (1 << PWM2);                             if(OCR0B < 255)                                   {                                     OCR0B += (255 - OCR0B)>>2 ;                                     //OCR0B++;                                 }                             if (New_PWM2 < (Initial_2 + 8))                                 {                                     Initial_2 = ((7*Initial_2)>>3) + (New_PWM2>>3);                                 }                         }                     else if(New_PWM2 < Initial_2)                         {                             if(OCR0B > 0)                                   {                                     OCR0B -= (OCR0B >> 4)+1;                                     //OCR0B--;                                 }                             else if(OCR0B <= 0)                                   {                                     DDRD &= ~(1 << PWM2);                                 }                         }                               */                     Old_PWM2 = New_PWM2;                       break;                                    case 3:                     A2D_Channel_Select(2);                            //select ADC channel 2                     Amb_Sensor_3 = ADC_read();                     IR_3_ON;                                        //turn on IR 3 LED, PORTB |= (1<<6)                     Delay();                                        //delay for the IR receiver to settle                     Sensor_3 = ADC_read();                            //take ADC reading                     IR_3_OFF;                                        //turn off IR 3 LED                       New_PWM3 = (Sensor_3 - Amb_Sensor_3) - Initial_3;                     if(New_PWM3 < 0)    { New_PWM3 = 0; }                                        New_PWM3 = ((7*Old_PWM3)>>3) + (New_PWM3>>3);                     if(OCR2A >= 1)    {DDRB |= (1 << PWM3);}                     else { DDRB &= ~(1 << PWM3); }                     New_PWM3 <<= 2;                     if(New_PWM3 > 255)    { New_PWM3 = 255; }                     OCR2A = New_PWM3;                     New_PWM3 >>= 2;                 /*                     if(New_PWM3 > Initial_3)                         {                             DDRB |= (1 << PWM3);                             if(OCR2A < 255)                                   {                                     OCR2A += (255 - OCR2A)>>2 ;                                     //OCR2A++;                                 }                             if (New_PWM3 < (Initial_3 + 8))                                 {                                     Initial_3 = ((7*Initial_3)>>3) + (New_PWM3>>3);                                 }                         }                     else if(New_PWM3 < Initial_3)                         {                             if(OCR2A > 0)                                   {                                     OCR2A -= (OCR2A >> 4)+1;                                     //OCR2A--;                                 }                             else if(OCR2A <= 0)                                   {                                     DDRB &= ~(1 << PWM3);                                 }                         }                               */                     Old_PWM3 = New_PWM3;                       break;                                    case 4:                     A2D_Channel_Select(3);                            //select ADC channel 3                     Amb_Sensor_4 = ADC_read();                     IR_4_ON;                                        //turn on IR 4 LED, PORTB |= (1<<7)                     Delay();                                        //delay for the IR receiver to settle                     Sensor_4 = ADC_read();                            //take ADC reading                     IR_4_OFF;                                        //turn off IR 4 LED                       New_PWM4 = (Sensor_4 - Amb_Sensor_4) - Initial_4;                     if(New_PWM4 < 0)    { New_PWM4 = 0; }                                        New_PWM4 = ((7*Old_PWM4)>>3) + (New_PWM4>>3);                     if(OCR2B >= 1)    {DDRD |= (1 << PWM4);}                     else { DDRD &= ~(1 << PWM4); }                     New_PWM4 <<= 2;                     if(New_PWM4 > 255)    { New_PWM4 = 255; }                     OCR2B = New_PWM4;                     New_PWM4 >>= 2;                 /*                     if(New_PWM4 > Initial_4)                         {                             DDRD |= (1 << PWM4);                             if(OCR2B < 255)                                   {                                     OCR2B += (255 - OCR2B)>>2 ;                                     //OCR2B++;                                 }                             if (New_PWM4 < (Initial_4 + 8))                                 {                                     Initial_4 = ((7*Initial_4)>>3) + (New_PWM4>>3);                                 }                         }                     else if(New_PWM1 < Initial_4)                         {                             if(OCR2B > 0)                                   {                                     OCR2B -= (OCR2B >> 4)+1;                                     //OCR2B--;                                 }                             else if(OCR2B <= 0)                                   {                                     DDRD &= ~(1 << PWM4);                                 }                         }                           */                     Old_PWM4 = New_PWM4;                                        Timer1_Overflow = 0;                    //reset                                                           Sensor_Values_Updated = 1;                //new values ready                                              break;                   }//end switch     }//end ISR  

Topic by CulturalC   |  last reply

Implementation of two way communication

Hi, I'm working on a project where we're working on a tele-operated robot and we are looking to include the ability to have a conversation. We would be looking to use earbuds and a microphone on the operator side and a speaker and microphone on the robot side. Does anyone know how to go about implementing this? It needs to be hands free on both ends as the operators arms are being mapped to the robots arms. Thank you.

Topic by ArnoldM27   |  last reply

gotta admit, kinda bummed by contest results

I recently entered a contest with what I thought was a good project. I'm no wizz and surely expect there to be strong competitors out there all with different projects. I have no idea what criteria is used in judging but to have several versions of the same thing (a bluetooth speaker) win several slots in the contest left me both bummed and scratching my head. What's done is done but I feel like this is akin to running a contest of car repair and having 3 entries on How to Change a Tire win.

Topic by ke4mcl   |  last reply

Instructables as an Extracurricular

Really weird question. I didn;t know where else to ask. So I really love tinkering, building things, and making Instructables. I'm applying to college and thought putting it on would be a good idea. However, I really don't know what to 'call' it. if the admissions officers don't know what Instructables is - it looks really weird. Online Tech Blogging would be a wrong way to phrase it. Tinkering is far too general. I'm looking for a short and specific term that includes my love for building/making stuff, and my interest in instructables. Thanks for the help, and I'm sorry if this is the wrong place to ask :(((((

Topic by adithyashok   |  last reply

Viewing my concept instructables possible?

Hi, Was just wondering; I saved an instructable I was working on without actually publishing it. Somehow I can't seem to find the draft/concept version of the instructable I made. How can I find them / navigate to them on the website? thanks in advance, Joost

Topic by joostvanpoppel   |  last reply

Microwave generator...... any datasheet for DAIHEN

Hi.I have a microwave generator from DAIHEN. It is a 3kW magnetron that makes 2450MHz wave.The model is ATP-30B(high voltage unit) and SMA-30DI(magnetron unit).This devices made in Japan and I need DATASHEET.If there is any clue that can help me plz inform me. thx

Topic by HesamP1   |  last reply

UV filtration in your fish tank or small fish pond

Year after year the topic "I have a fish tank" seems to go more out of control. What was once a hobby just to have some fish can now be a design feature both in your home and inside the tank. Realistic looking lasdscapes, optical illusions that make you think the tank is much bigger and the list goes on. But one thing that now always pops up is the must have thing of UV filtration. Or to be precise: UV-C sterilisation! Now, if we trust Wiki and our big water suppliers then UV-C will literally kill anything alive that comes into contact with. So of course it would be a good thing to have for your tank - or not? UV-C is very dangerous for your eyesight and quite harmful for your skin! Looking into a proper UV-C lamp without protection means you can go blind! Even good sunglasses might not have enough protection in the UV-C range, so only use them for additional protection but never without and glass between you and the lamp! Don't be a fool! Treat UV-C seriously! You would not look into the full sun with your sunglasses and would not expose your eyes or skin to a powerful laser, UV-C is to be treated the same way! Let's start by using some boring text to explain the concept a little bit. On a large scale special and quite powerful systems are used to treat our drinking or pool water. Here special UV-C lights with a wavelenghts of 260nm or below are used to shine through the water passing by. There are two key factors here. a) the wavelenght b) the water flow rate and the corresponding time the water is in contact with the UV light To ensure all bacteria, viruses, algae and other harmful organics are dead the water must circulate for long enough so even the last water molecule had a few seconds of exposure. All this only works good with "crystal clear" water for obvious reasons as otherwise the UV has to be even more powerful to pass through. Single cell organisms literally crack into pieces similar to being exposed to gamma rays, more complex cells like algae have their cell membranes damages and the DNA suffers as well causing reproduction loss and early death. Even some chemicals break down, most importantly here chlorine based substances. Differences within the UV-C range! If you bothered to check Wiki about the topic of UV-C you will already know that only certain wavelengths within this spectrum will actuall be powerful enough to do what we want it to do. And here is the first problem for us hobby users. Most cheaply advertised "sterlisation lamps" you find in places like Ebay are actually totally useless. Stating to be selling a UV-C light to sterilze your water in such a case is still not considered to be fraud though. Simply because it still does what it supposed to do, just very slow and with very little effect. Only the so called "short wave" UV-C range is powerful enough! To avoid loosing business during the times of the biggest hype in 20 years no seller will actuall state the available wavelengths. That means without this info anywhere you can be certain the advertised lamp is of little to no use. Even those advertised to be short wave UV-C might not be the real deal. However, if a decent manufacturer is behind the actual lamp used it is possible to check the datasheet for these performance figures - but again most cheap systems come with no-name lamps inside. Check the prices for a reputable UV-C light with the same lamp fitting, e.g. G23 and you will see it might cost more than your entire system. Ok, you have a poper short wave UV-C lamp or consider getting a canister filter with one in it.... Never, ever test your lamp without proper protection!!!!! UV-C will damage your eye within seconds! If you system or lamp does not provide a viewing port or shine through area then you have to place a piece of glass between you and the light! UV-C won't be able to penetrate normal window glass but will pass through quartz glass. Place the lamp in a box and cover with the glass. How make proper use of UV-C sterilisation... The replacement lights are quite expensive, so let's see how to get the most out of them. As said before exposure is the key factor so the flow rate of the UV system must match tank size and flow rate of your filter system. Canister filters with a build in lamp should be designed to match but I will tell you later what to look for ;) Most of us will prefer to have a in-line system if there is already a good canister filter at work, so I will focus on those and rop in solutions. If you compare in-line system you might notice that some quite small and low power units claim to allow for the same flow rates as for example 40W units. Some are fraud and just want to sell while others use simple physics to make the claim true. A good system will utilise an auger like "ramp" that forces the water to circulate around the tube many times - causing up to ten times longer exposure rates. Others create this sprial effect more like a vortex with some diverters and modified inlets. The later seems to be less efficient though with low power lamps. An in-line system should be on the outlet side of your canister filter so the best quality water will pass through it. A drop in solution should be used alone and without the existing normal filter pump you might have in there. Ok, got it, but how do I actually use it now? Despite common thinking a UV-C system should not run 24/7 like your normal filter. You really only need it to solve problems you should not have in a healthy tank! It is not a magical solution to make your underlaying problems go away ;) Let's start with the most common reason someone buys a UV-C system: An algae or bacterial outbreak causing greenish or milky water. If that developed slowly over a period of weeks then you would be better off to do a good clean of the tank and filter plus a decent water exchange. A few drops of meds will do the rest. And if you constantly get algae growing on your glass, ornaments and plants then your nutrient levels and water quality is not right anyway and needs a good check. But of course there is also the problem of light - too much for too long and unwanted gree appears everywhere. If in doubt reduce the light power, shade out natural light or reduce the on time for your lights. Having said that we now face the problem of a sudden outbreak after introducing new fish or plants. If you don't have a quarantaine tank chances are that sooner or later you get unwanted or even harmful guest into your tank. Here the UV-C will be beneficial, which is why a canister filter with build in light should have a seperate switch or power supply for the light. After an outbreak or while introducing new life into your tank the UV-C will remove a lot of the things that we don't want to bring along. For new life I leave the light on non stop for a week, that is for a small 4ft tank with 200 liters. To control an outbreak it depends on how bad it is. I assume here you can still see the back of your tank  but that the water either appears greenish or slightly milky from bacteria. As a personal thing I prefer to to remove and clean my filter material before treating a severe outbreak. Once done I fill the filter with a mix of activate carbon material and fine filter wool. Reason for this quite simple: The outbreak causing stuff is already in your filter material and will be a constant source of re-infection. And since breaking down all this bad stuff causes even more bad stuff to be produced as biological waste we want to discard it properly once done. Using just fine filter wool and activated carbon also reduces the flow rate bit if compacted ;) Now we can turn on the light and pump and forget about it for a while. It is not recommended to run UV lights on a timer as you want them on all time to prevent short lifespan and have ongoing treatment of the water. Good idea to take a picture at the same of a day from now on to compare and check results. After 3 days the water should definately be clearer, if not then either your filter material is packed too losse or the lamp is no good. Once the water appears to be clear do a readin test - take a newspaper behind the tank and check if the text is clear - blurry means the water is still not clean. You will reach a point where the water quality will not further improve as much as in the days before. This is the time where you discard or clean out to dry your filter material and put the original stuff back in. The activated carbon should be discarded of course. You cleaned filter material will now need a certain time to grow enough good bacteria to go back to the old performance. During this time you should still leave the light on. In most cases with enough fish and plants in the tank a week should be sufficient. After that you can leave the light off and keep the tank fit and healthy. Special case: Algae everywhere! Especially after getting a new plant you can end up with quite pesty algae growth. Be it these long ghost hair types or in a bad case the black stuff growing on plants, ornaments and the glass. I have even seen tanks with algae covering the entire bottom of the tank causing the gravel to look like carpet. Here I can only advise to set up a quarantaine tank for your fish. Then remove all infested material for manual removal and cleaning. Infested plants should be cut clean and what can be boiled should be boiled in water for a few minutes. Now start scrubbing in the tank with ongoing water replacements. I prefer to let everything settle over night without any bubbler or pump running. This way I can suck up a lot of sediment the next day. If you can remove all plants and fish you can now use hydrogen peroxide and add it to your tank water. But this is only feasable for small desktop tanks. Before using the UV as above to cure an outbreak you should consider all water one last time. Allow at least 2 weeks with ongoing water checks before adding plants back in and another week before placing your fish back in the tank. The week before adding fish should be used to monitor the plats for any signs of algae you might have missed - if you find any remove it! A week after the fish is back in you can turn off the UV light. Underwater UV-C light!? In most online stores you will find quite cheap UV lights to be advertised as underwater or in tank use. Although it might sound tempting you should be well aware of the dangers of using them. The glass of your tank will block the harmfull UV rays but the water surface won't, so either don't ever look at it or use proper sunglasses with real UV protection. Apart from the dangers to you these lamps are not just cheap in price but also cheaply produced. That means there is no way of telling how much or how little UV-C is produced. If they are good then you still need to know in what type of tank setup you can use them. As plants can tolerate a bit of UV a placement as far away from the nearest plant should do, especially if you can place a bubble wall betwenn light and plants. The fish is another thing as some seem to be unaware of the danger in their tank. This means they can get too close to the light but I have not found any articles explaining how harmful UV-C is to fish or their eyesight. I guess once your fish starts to bounce into everything you know... ;) My advise is to stay away from the idea of hanging a UV-C lamp in your tank, the risk for you and your tank is just not justified. If you need to go cheap then get two or thre of these lamps so you have spares. But use them externally ;) Meaning: Take a UV proof plastic container of small size and place the light in there. To be really safe tape the lid and all holes for the hoses with black tape. Place the container above the water level of your tank and if you only have an internal filter pump push a suitable sized hose into the outlet to feed into you canister. Check how high you pump can make it and place the outlet or overflow slightly below this level. When to change the light? If you made it all the way down here then you might already had the benefit of using light to "cure" your tank. Now we are faced with the high replacement cost for the lamp itself. Ususally only flouroscent tubes are used. It is always good to check after purchase what type of lamp and manufacturer (if there is one) was used. In some cases the system itself is like an inkjet printer: Just a cheap way to make you buy the consumables. Let's say you new in-line filter was priced at $100 to have a nice round number, some are cheaper some much more expensive. The lamp used might be an exotic type and not even be available easy, so before you buy your system check where you can get spares, not just the lamp of course. A replacement lamp can be as ceap as 20 bucks or cost even more than your system if you need to order it elsewhere. The quartz glass sleeve can break too meaning you then need a lamp and cylinder. Going with a reputable brand and paying a bit more certainly helps to get spares in the future. Let's just assume you either got your system in bulk due to the price of replacement lamps or can get them at a reasonable price. UV-C lamps are not like your normal flouroscent light tubes you have around or maybe even on top of your tank. Consider them like the tubes used in the now unhealthy tanning beds. After a certain amount of time they no longer produce enough of the short wave UV light that we need. As you can't see it and most of us won't have the means to specifically measure it we have to trust manufacturers recommendations. For most good brands the numbers are the same: 8000 hours max. Considering the costs it does make sense to keep written track of the usage. Not too hard since we won't use them like normal lights but instead have them on for a week or more without turning them off. I recommend to have a replacement at hand long before you need it. A lamp can fail premature, crack or simply burn out. The 8000 hours are based on 24 hour usage, so one day on, one day off. This could mean for us the lifetime can be slightly longer but I would not go over 9000 hours. As a rule of thumb: If the water does not show good signs of getting clear on day thre the lamp is due.

Topic by Downunder35m   |  last reply

email images not displaying

I'm not getting images in my Instructables newsletter emails. Almost all of them are broken except for the We're Hiring graphic. The links in the image placeholders work. But without the images I'm not inspired, so I don't bother to click and follow the link. I have no problem with any other emails from other websites. I'm using Outlook 2007 on Windows Vista. (Please don't suggest using a different email program.) I've added Instructables to my "Safe Sender" list and "Safe Domain" list. What's going on?

Topic by PaulyG10657.   |  last reply

Email newsletter not displaying images

The last few email newsletters I received are not showing images. Prior to maybe a month or so ago this was never an issue. I'm on Windows XP service pack 3, using Outlook 2003, my internet browser is Firefox 47.0.1 but the problem is email related. In the latest newsletter, one image actually does display. And 3 link buttons at the bottom displayed - everything else has the dreaded red X instead of the images. Screen captures below.

Topic by DesignCutters.   |  last reply

Is there a way to measure for methanol in your final product

Is there a way to measure for methanol in your final product?

Topic by Tjmcwi   |  last reply

Grandma got run over by a reindeer rip offs Put another log on the fire

Hi Everyone, Have you notice this song Grandma got run over by a reindeer Is a rip off of this song I not trying to ruin Christmas just thought its hilarious, when my 8 year old was singing "grandma got run over by a reindeer" , I gave her some lines form "put another log on the fire" Now grandma is having a really bad Christmas!

Topic by liquidhandwash 

Cheap Slot car track

I LOVE using slot cars. I HATE the price of them. Does anyone know where I can get some cheap slot car track. When I say cheap, I mean less than $60 for a good bit of track. I plan on slowly building up my main straight away(s) to be long so I can test speed. Any site or info would be nice. But' I'm also considering build the track myself. Meaning, I use a router and and a couple pencils and string to build it out of wood. I know it takes time but I'll have 2+ hours a day with nothing to do. Help? Anyone?

Topic by ry25920   |  last reply

How to Help Out Around Instructables

People often ask how they can help at Instructables, especially if they are too far away to come in person. Below are some things you can do to help. Welcome new users New users are often confused about Instructables and how to get the most out of it. I used to welcome people, and when it got to be too much for me alone, we turned it over to the Instructables Robot. Unfortunately, the Robot isn't that good at responding to questions, so that's where you come in. You can welcome new members to the site by introducing yourself and leaving a comment on their Orangeboard (found at the bottom of every member's profile page). Here's an example of what the Robot says: Hello! Welcome to Instructables! I am the Instructables Robot. My job is to alert you whenever someone leaves you a comment or sends you a private message. I spend most of my day sending email. I like sending email. You probably want to upload an image to your profile. You can do that here, as well as change some of your other account settings. After that, check out How to write an Instructable, The Guided Tour of Instructables, and the Help Forum if you have any questions. Welcoming people can be very rewarding, and I really miss having the time to do it myself. Leave/respond to a comment For some, it takes some courage to make a first comment or post a first question, and it feels really good to have that question answered. So, a huge way to help out is to engage new members with a comment -- it shows them the strength of our community and gives new members a great first experience. Help out in the Answers Section You're smart, share your knowledge with others. You definitely know the answer to a question posted in our Questions & Answers section. Help us fix Bugs We're not perfect, and sometimes we break the site. If you find an issue with the site you can post a bug report in the forums. If you do a really good job of reporting a bug you can earn a free Pro Membership! Help Authors with their Instructables Think you know what makes a good Instructable? You can share your insight and help authors make their work the best it can be by offering support in The Clinic. Are you doing something more to help out around the site? Leave a comment below and let us (and other members) know what you are doing to help welcome people and keep the site awesome!

Topic by ewilhelm   |  last reply

Getting the Arduino to Convert analog signal from guitar into correct frequency

Hello Everyone, I was wondering if anyone can help me with a simple solution to my problem, I was to be able to get the sounds from my guitar into my ardunio and have the correct frequency be stored. I can get the guitar connected to the arduino and numbers come out of the serial monitor but they don't make sense, i need to have the correct frequency come up for each note i play, I have looked at a few solutions but being a beginner to this some go over my head or they just didn't work. Can anyone help me or point me in the right direction to be able to do this? Thanks  P

Topic by paddykoolster   |  last reply

Watering Pump with LCD, Arduino. Need some help with code

Hi, Building watering unit with LCD, based on Arduino mega. I couldn't get correct value on LCD. I want to show current sensor readings. Could you please help #include #include LiquidCrystal_I2C lcd(0x27,20,4); int PUMP = 13; int sensor = 8; int val; const int DigitalInPin = 8; int sensorValue = digitalRead(8); void setup() {   pinMode(13,OUTPUT);   pinMode(8,INPUT); lcd.init();                      // initialize the lcd lcd.init(); delay(100); } void loop() {    val = digitalRead(8);     if(val ==LOW)   {   digitalWrite(13,LOW);   }   else   {   digitalWrite(13,HIGH);   }   delay(400); lcd.backlight(); lcd.setCursor(0,0); lcd.print("Soil Moisture:"); sensorValue = digitalRead(8); lcd.setCursor(0, 1); lcd.print(sensorValue); }

Topic by PASHGEN   |  last reply

Arduino Motor Control Shield

Hi! I am having trouble with two motor control shields. 1 - Arduino motor control shiels                                               // Hole-through devices  2 - Adafruit motor control shield V2                                         // SMT devices My problem is the installing the libraries.                                // will not compile,  need an AFM !!! I have done this before, but every now and then I'll get stuck or confused doing it.                    I've read the tutorials and seen the Youtube, what can I say I'm still stuck.                          // simple get hard sometimes I normally build my own circuits and programme them, but lately, I'm buying them already made and most of them need a library. . If anyone can help me I sure would be thankful. Thanks Frank G.   

Topic by 56Frank   |  last reply

Anyone using Tinkercad vs 123D Design? Curious about how and why people use one or the other.

Tinkercad is great for beginners, while 123D is slightly more advanced with features.  Does anyone prefer one over the other for different reasons?

Topic by andrewt   |  last reply

temperature logging with raspberry pi

New here, and to Pi/Python looking to log data from a few different sensors from Atlas Scientific (RTD & PH).  I've gotten really stuck so fare in getting these going and was wondering if anyone here can help me out.  so far I've used this code:  import smbus import time import datetime #SMBus(0) - Raspberry Pi Model A #SMBus(1) - Raspberry Pi Model B bus = smbus.SMBus(1) #I2C address of sensor address = 0x66 def temperature():     rvalue0 = bus.read_word_data(address,0)     rvalue1 = (rvalue0 & 0xff00) >> 8     rvalue2 = rvalue0 & 0x00ff     rvalue = (((rvalue2 * 256) + rvalue1) >> 4 ) *.0625     #print rvalue1, rvalue2     return rvalue print("Temperature Data Logger\n") while True:         #Open Log File     f=open('tempdata.txt','a')     now =     timestamp = now.strftime("%Y/%m/%d %H:%M")     outvalue = temperature()     outstring = str(timestamp)+"  "+str(outvalue)+" C "+str(outvalue*1.8+32)+" F"+"\n"     print outstring     f.write(outstring)     f.close()     #log temperature every 10 seconds     time.sleep(10) I've got the two sensor boards connected to the raspberry pi 3 mounted via a Whitebox Tentacle T3.   The boards are in i2c mode and i can see them using sudo i2cdetect -y 1 (they show up address 63 and 66)  but when i run this program above I just get a red error light when it reads the temperature.   The log file reports a measurement of 2C and 35.2F which is not correct but the red light on the board tells me that the Pi is trying to connect with it.   Anyone able to help?

Topic by Chair_t 


Every thing is okay except line follow command ,,,when i say line follow it only goes forward but does not follow line my code is String voice; int LS=10; int RS=9; int LED=13; char getstr; int in1=3; int in2=4; int in3=5; int in4=6; int ENA=2; int ENB=7; long duration, distance; int trigPin=A0; int echoPin=A1; int buzzer=8; void forward() {   digitalWrite(ENA,HIGH);   digitalWrite(ENB,HIGH);   digitalWrite(in1,HIGH);   digitalWrite(in2,LOW);   digitalWrite(in3,LOW);   digitalWrite(in4,HIGH);   } void back() {   digitalWrite(ENA,HIGH);   digitalWrite(ENB,HIGH);   digitalWrite(in1,LOW);   digitalWrite(in2,HIGH);   digitalWrite(in3,HIGH);   digitalWrite(in4,LOW);   } void left() {   digitalWrite(ENA,HIGH);   digitalWrite(ENB,HIGH);   digitalWrite(in1,LOW);   digitalWrite(in2,HIGH);   digitalWrite(in3,LOW);   digitalWrite(in4,HIGH);   } void right() {   digitalWrite(ENA,HIGH);   digitalWrite(ENB,HIGH);   digitalWrite(in1,HIGH);   digitalWrite(in2,LOW);   digitalWrite(in3,HIGH);   digitalWrite(in4,LOW);   } void stop() {   digitalWrite(ENA,LOW);   digitalWrite(ENB,LOW);   } void on() {   digitalWrite(LED,HIGH); } void off() {   digitalWrite(LED,LOW); } void line(){ if(digitalRead(LS) && digitalRead(RS))     // Stop   { stop();   }     if(!(digitalRead(LS)) && digitalRead(RS))     // right   { right();   }     if(digitalRead(LS) && !(digitalRead(RS)))     // Turn left   { left();   }     if(!(digitalRead(LS)) && !(digitalRead(RS)))     // Forward   {     forward();   } } void setup() {   pinMode(LED, OUTPUT);   Serial.begin(9600); pinMode(LS, INPUT);   pinMode(RS, INPUT);   pinMode(in1,OUTPUT);   pinMode(in2,OUTPUT); pinMode(trigPin, OUTPUT); pinMode(echoPin, INPUT);   pinMode(in3,OUTPUT);   pinMode(in4,OUTPUT);   pinMode(ENA,OUTPUT);   pinMode(ENB,OUTPUT); pinMode(buzzer, OUTPUT); } void loop() {   while (Serial.available()){ //Check if there is an available byte to read      delay(10); //Delay added to make thing stable     char c =; //Conduct a serial read     if (c == '#') {break;} //Exit the loop when the # is detected after the word     voice += c; //Shorthand for voice = voice + c   }   if (voice.length() > 0){     if(voice == "*go ahead"){       forward();       }     else if(voice == "*go back"){       back();       }     else if(voice == "*turn right") {       right();     }     else if(voice == "*turn left") {       left();     }     else if(voice == "*light on") {       on();     }     else if(voice == "*light off") {       off();     }         else if(voice == "*stop") {       stop();     } else if(voice == "*line follow") { line();           }       voice=""; //Reset the variable after initiating   } }

Topic by BibekP4   |  last reply

Bumping old question w. insufficient responses?

I posted a question a year ago and got a few responses, but nobody quite answered in the way that would have been useful.  I did appreciate the replies (and expressed so), but none hit the nail on the head. The thread went dormant, you could say.  Is there a way to bump the thread up in the specific forum?  Thanks.

Topic by Joel_BC   |  last reply

favorite bands of all time

What is your favorite band? what type of music is it and whats your favorite song of theirs?

Topic by michael J. caboose   |  last reply

need a cheap way to use a servo and switch on LED's with a remote

I need to move a small servo left and right and have it stay where I leave it and power 1 or 2 sets of lights with a simple remote but I have no idea how to achieve this apart from use a radio control transmitter/receiver and an electronic speed controller. I see there are lots of little devices out there that could work but being a noob at electronics I'm not too sure what will work. I found this, would something similar to that work? It is 12v, my servos would only take about 6v max though, same with the LED's, I suppose I could use something to lower the voltage output? Cheers.

Topic by 1/104   |  last reply

Tips and Hints

This is my invention for the day.  Use of magnetic tool holders is a very old, but handy way to organize tools.  My contribution to Magnetic Tool Holders is to use small, strong magnets (12 mm diameter) attached to a metal bar or in the photo, to my card table edge.  That in itself is still not very significant. However HOW the tools are hung from the magnets is significant. The problem:  If I put the magnets vertically and hang the tools vertically, the surface area of the magnet is such that often the attraction between the tool and the magnet causes the magnet to stay with the tool instead of with the table.  A magnet sticking to the tool, can be very annoying. The solution:  Placing the magnets horizontally--at the bottom--AND hanging the tools by their tips allows for very easy detachment and attachment.  The magnetic force is strong enough to hold some very heavy tools, like the pliers or long nose pliers without any difficulty.  The tools are easily removed and easily replaced.  This would also apply to any magnetic strip.   The key thought of the day: Hang tools from magnetic tool holders by their tips. Of course, another solution is to glue the magnets to the supporting bar--wood or metal--and clamp the supporting bar to the table.  That works as well, but is more permanent and is a little more work.  Also, if the magnets are allowed to attach by their full surface area to the tools, the tools are hard to remove.  

Topic by stannickel   |  last reply

ICL7107 and LM35 based 7-segment thermometer

I'm trying to create a digital centigrade thermometer based on an ICL7107 3 1/2 digit 7-segment driver/ADC and an LM35 linear centigrade temperature sensor but I'm having a few problems. There doesn't seem to be much online about using the ICL7107 with a LM35 and most of the schematics available are for volt meters, but that's not a massive problem as the LM35 gives 10mV/C linearly. I'm just trying to go based on the few schematics I have found but I'm wondering about the supporting components for the LM35 which seem a little too simple. The first schematic I found was from a Hungarian electronics forum and seems to depict a diode and amplifier being used for the temperature sensing which seems like a bad idea to me. The second seems more like what I'm trying to do. The other few things are the negative voltage source, the first schematic shows an inverter being used as does the datasheet, but the second schematic shows an LMC7660 voltage converter which seems like a better option to me. The second one does also show three diodes in series used to drop the voltage for the LED displays which doesn't seem like the best idea, but I can't think of a better way to do it without attaching resistors to each one as the number of lit segments will be variable. The supporting components for the ICL7107 seem pretty consistent between the two and the schematic so I'm confident those are correct, but I'm looking for some advice on how to connect the LM35 in a way that will give me an accurate readout. Thanks!

Topic by andy70707   |  last reply