Motor/propeller selection for quadcopter

Hello Instructables! We are a team of engineering students that want to get started in the world of multirotors. Our objective is to build a long endurance/high payload quadcopter for industrial applications, and we plan to innovate in the power system area. So, without further ado here's our first problem. I've searched the internet for a while now and I've struggled to find information on how to choose an appropiate motor-propeller combination. I know the total maximun thrust should be a bit more than two times the the total weight but motor and propeller manufacturers rarely list the "thrust per rpm" of their props. Our initial estimation for the quadcopter's total weight is 3,3 kg. considering 200 g for each motor. I did manage to find this static thrust calculator but I have no idea how reliable it is since it doesn't say how the thrust is calculated. ( So that's about it. Any help would be greatly apreciated, no matter how small. It can be advice, information sources, or even builds that are similar to what we want to make and have already been tested. Thank you very much for your time! PS: Excuse me if my english sounds a bit weird, it just isn't my native language.

Topic by Joakov   |  last reply

Laser cutter software issue

I use a laser cutter that runs on LaserCut 5.3 To create my files, I draw in Inkscape, save as a DXF file, then import that into Lasercut5.3 Unfortunately, importing into LaserCut5.3 creates artifacts in my files - polygons are created where none were before, and lines are invisibly doubled up, meaning that the laser cuts some lines twice, which wastes time, energy, and can spoil a project if a line goes too deep. Two typical examples are below. In an ideal world, the "e" would come out as two continuous lines (inside & outside).  Intead, it comes out as three lines, and the straight parts of the lines are "doubled over" - it cuts twice. Where two or more straight lines are contiguous, like the "k", the sections gain extra lines that break it up into smaller polygons. (I have shown the extra lines in red). Both cases are fixable, on a file-by-file basis, but, in the clunky LaserCut5.3, the fix can take longer than the original design. Has anybody else experienced this issue, and how did you fix it?

Topic by Kiteman   |  last reply

Arduino Project Help

Im in the process of writing some software to control our workshop saw. by control i mean control the position of the saw, all the safety sensors and speed controls are already in place. the current control unit im replacing is dead, and there no longer in manufacture and we cant find a replacement. some of the code is from another developer who was training me, he wrote the encoder part for me.. would someone be willing to help me finish the project or even point me in the right direction of the projcet ? Regards

Topic by mathewbuer 

Web server hosting on Raspberry pi using usb Dongle

I need to host a webpage on Raspberry pi but for internet connection i can't use a router or wifi card. I need to know that can usb Dongle be used to provide public ip to a server running on raspberry pi so that it can be accessible over internet.

Topic by prithvi88   |  last reply

Transistor Voltage Inverter

I am a newbie and was hoping someone could assist me. Given the following schematic which takes a voltage of 12v and considers it off and a voltage of 2 volts and considers it on can someone tell me what changes would need to take place regarding capacitors and resistors (if any) to account for 20v instead of 12v? Meaning that when 20v is considered off and 2v is considered on.

Topic by TimothyE2   |  last reply

Help please!!! Ghetto parallel port uc programmer issue!!

Someone please help!! I have made the ghetto parallel port programmer  from here : I am stuck with this problem since a very long time!! > "make.exe" program avrdude -p attiny2313 -P lpt1          -c dapa               -E reset  -U flash:w:LED_Demo.hex avrdude: AVR device not responding avrdude: initialization failed, rc=-1          Double check connections and try again, or use -F to override          this check. avrdude done.  Thank you. make.exe: *** [program] Error 1 > Process Exit Code: 2 > Time Taken: 00:01

Topic by KotamrajuS   |  last reply


I am currently building an RC hovercraft, I plan to use a single 12 volt 2.1 amp hr lead acid battery to feed both the lift fan for the skirt and the power motor for the drive. However the fan for the skirt is 12v 0.3 amps. How can I reduce the feed to the required amperage with out affecting the other feed from the same battery that will power the drive

Topic by Seafarer77   |  last reply

how to maintain the intensity of IR at long distance and make it directional

We are trying to make an infrared shooting game which includes a transmitting gun and a receiving everyone knows IR is not directional so at long distance it will diverge but in shooting game we need a pointed IR beam. is there any technique implement this?? we need help..! :(

Topic by FypB   |  last reply

How to connect laptop battery to any dc application

Hi. I would like to know, how you can use spare laptop battery to any dc application. Once the external battery is charged, i want to harness the power from the battery, which type of connector, usb , etc can be used to connect the dc application ? any kind of assistance would be very help full. Thanks, Richi

Topic by RichiV   |  last reply

Hard drive motors?

I need to get a harddrive motor up and running, it has four pins for power, does anyone know exactly what these pins or which is which, the motor is from a harddrive from an old xbox, i worked hard get this wretch out all the way down to the motor, honestly microsoft should build bomb shelters, and the casing of the hard drive is pretty tough, on of the boards on it needed some friendly persuasion from a hacksaw and a hammer after I removed the apparent retaining screws, all 7 million of them, by the way I may do an instructable on how to open an old Xbox with nothing more than a swiss army knife, and it doesn't get damaged at all. To figure out the pins is all I need, left to right arrangement would do I have figured out which way up the bottom is but the crazy hieroglyphis in microscopic size reveal little about the connections,

Topic by killerjackalope   |  last reply

[Help] bicycle proximity sensor

Hello guys i would like to start making a proximity sensor the idea is to mount it on the back of my bicycle when an object/vehicle come close it gives me reading with distance and maybe a beep or something like that,the question is i found there are 2 methods one using IR and one using ultrasonic,which one is cheaper and which one is better and easier.this is supposed to my first instructable involves programming.

Topic by Mido Masry   |  last reply

Free multiple photo resizer software? [FOUND]

Hello Instructablers! As my internet is very slow, every time I want to create an ible, I have to resize all of my pictures to 800x600 manually so I am looking for a software that can resize multiple pictures to resize a whole picture folder but that is able to save a copy that is resized and the original one. Anyone knows a free software that do so? Thanks in advise. EDIT: Thanks to Downunder35m for suggesting me Irfan View, It really works well! :) I'll now be able to make more instructable tutorials as I won't have to resize all the photos manually! :P Electrospark

Topic by Electrospark   |  last reply

motion activated alarm, sort of

My wife just bought a tin pig that is about two feet tall and she wants me to see if i can make it squeal when someone walks up to our front door.  i figure it sounds like an easy project but i am not sure.  i have enough experience wiring, soldering, and general tech stuff.  i have read up and can guess that i will need a pair sensor and some sort of  micro controller, but i am unclear what or what to do with it.  the goal is to have a piece that i can put inside the pig and have it detect a visitor and then trigger a sample of a pig sound.  i know its silly, but i do what the wife asks!! ideas of maybe a link to something specific would be helpful!

Topic by bobchabot   |  last reply

Virtualwire RF 433mhz Voltage problem mk2

Hi, I have this code and have modded it a bit, i was wondering if there was a way of making the pincode more than 1 digit long? Also i have got the code sending command and pin code when buton to pressed and stopping when released and the receiver end reading it and seeing it stop, sending a pin high when it reads it but i cant get i to go low when it stops receiving it. wen ever it looks like it will work It seems to make the pin go to 0.16 when low to 0.24 when high. can you help? tom Transmitter code #include int button = 2;   void setup() {     Serial.begin(9600);     vw_set_ptt_inverted(true);     vw_setup(2000);     vw_set_tx_pin(4);     pinMode(button,INPUT);     pinMode(button,LOW);   }   void loop() {     while     (digitalRead(button) == LOW);      sendMessage("1", "5");      //delay(10000);   }   void sendMessage(char* pinCode, char *data) {      if (strlen(data) > 0) {       double startTime = millis();       Serial.println("Sending...");       int msgSize = (strlen(data) + strlen(pinCode) + 1);       char packetData[msgSize];       strcat(packetData, pinCode);       strcat(packetData, ".");       strcat(packetData, data);       Serial.println("Debugging ");       Serial.print("Sending Command: ");       Serial.print(data);       Serial.print(" with Pin Code: ");       Serial.print(pinCode);       Serial.print("\n");       vw_send((uint8_t *)packetData, msgSize);       vw_wait_tx();       double endTime = millis();       double timeTaken = (endTime - startTime);       Serial.print("Time Taken: ");       Serial.print(timeTaken);       Serial.print(" ms\n");     }    } Receiver Code #include   #include   int relay = 8;   byte message[VW_MAX_MESSAGE_LEN];   byte messageLength = VW_MAX_MESSAGE_LEN;   void setup() {     Serial.begin(9600);     vw_set_ptt_inverted(true);     vw_setup(2000);     vw_set_rx_pin(2);     vw_rx_start();     pinMode(relay,INPUT);     pinMode(relay,LOW);   }   void loop() {     while     //(vw_have_message())    (vw_get_message(message, &messageLength;))     {        int command = processResponse((char*)message, 1); //Byte Array Response and Pin Code.        if       // (vw_have_message());        (command) {          Serial.print("Received Command: ");          Serial.print(command);               Serial.print("\n");          digitalWrite (relay,HIGH);        }                   else //REMOVE          delay(100); //REMOVE          digitalWrite (relay,LOW); //REMOVE                 }    } int processResponse(char* message, int pinCode) {       char *p = message;       char *buf;       int o = 0;       int pin;       int command;       while ((buf = strtok_r(p, ".", &p;)) != NULL)  {          if (o == 0) {            pin = atoi(buf);                    } else {            command = atoi(buf);            ;          }          o++;       }       if (pinCode == pin && command > 0) {           return command;                 } else {          return 0;                         }   } This code only sends pin 8 from 0.14 when low to 0.17 when high. unless you remove the three lines marked REMOVE then it goes from 0.14 when low to 4.47 when high but stays there and will not go low when buttton it released. Please help

Topic by Senken 

Virtualwire RF 433mhz Voltage problem

Hi, i am trying to have it switch a 5v relay on pin 8 receiver side only when pin 2 transmitter side in held down. I have set up a XY-MK 5v transmitter , Push button to pin 2 live when pushed 3.3v Data rf transmitter to pin 4 and 5v,gnd and receiver, data pin 2 5v and gnd led to pin 8 and gnd Here are the codes. Transmitter Code= #include const int button = 2; const int transmit_pin = 4; const int receive_pin = 2; const int transmit_en_pin = 3; void setup() {   // Initialise the IO and ISR   Serial.begin(9600);   vw_set_tx_pin(transmit_pin);   vw_set_rx_pin(receive_pin);   vw_set_ptt_pin(transmit_en_pin);   vw_set_ptt_inverted(true); // Required for DR3100   vw_setup(2000);  // Bits per sec } byte count = 1; void loop() {   char msg[7] = {'h','e','l','l','o',' ','#'};   if     (digitalRead(button) == HIGH)   {Serial.println("on its way");   msg[6] = count;   //digitalWrite(led_pin, HIGH); // Flash a light to show transmitting   vw_send((uint8_t *)msg, 7);   Serial.println("on its way");   vw_wait_tx(); // Wait until the whole message is gone   //digitalWrite(led_pin, LOW);   //delay(1000);   count = count + 1; } } And receiver code = #include const int led_pin = 8; const int transmit_pin = 12; const int receive_pin = 2; const int transmit_en_pin = 3; void setup() {     delay(1000);     Serial.begin(9600); // Debugging only     Serial.println("setup");     // Initialise the IO and ISR     vw_set_tx_pin(transmit_pin);     vw_set_rx_pin(receive_pin);     vw_set_ptt_pin(transmit_en_pin);     vw_set_ptt_inverted(true); // Required for DR3100     vw_setup(2000);  // Bits per sec     vw_rx_start();       // Start the receiver PLL running } void loop() {     uint8_t buf[VW_MAX_MESSAGE_LEN];     uint8_t buflen = VW_MAX_MESSAGE_LEN;     if (vw_get_message(buf, &buflen;)) // Non-blocking     { int i;         digitalWrite(led_pin, HIGH); // Flash a light to show received good message // Message with a good checksum received, print it. Serial.print("Got: "); for (i = 0; i < buflen; i++) {      Serial.print(buf[i], HEX);      Serial.print(' '); } Serial.println();         digitalWrite(led_pin, LOW);     } } I have tried many different codes i have found and this works the best but.........the voltage is only going from 0.20v to 0.40 on the receiver pin 8. i need this to be 5v any ideas?

Topic by Senken   |  last reply

Arduino Uno Relay circuit

I am currently involved in a project that requires me to run a fan heater through coding in an arduino. I have decided to use a relay to act as a switch, to maintain the time period of heater running. I am using a DOAT 5V 20mA relay. I was wondering if anyone could help me with the circuit needed using a n-p-n transistor to power it while maintaining switch function. I know a circuit similar to the one below is needed, but im not sure about the capacitor and resistance values needed for a 5v, 20mA relay.

Topic by RoshanC1   |  last reply

that great feeling when you find instructables using your photo on their website menu

I just happen to notice my photo being used on the explore menu labeling the woodworking section. Feels pretty good!

Topic by SlickSqueegie   |  last reply

Macro lens attachments

I recently got a set of marco lenses for my DSLR, an old E300. They are the simple kind, basically a magnifying lens that screws onto the the existing lens system like a filter. My first impressions of this simple and relatively cheap alternative to a dedicated macro lens in the 400$ range were quite good. But I also found some downsides and would like to know if they are a general thing to accept or a result of poor quality standards. 1. Although about 20% of the lens are unused (nothing at all visible when covering the outsides of the lens) there is some nocticable distortion happening. Especially the corner areas of the image when the object fills the entire picture appear to be slightly bend. Is that due to the marcro lens being a single and cheap system or a general thing with these marcro filter lenses? 2. It is quite hard to to get a clear focus even with F22 settings and good light. With the X4 lens it is not too bad and leaves about 8mm of totally sharp image before it gets blurry. But when using the X10 lens I often have troubles getting a sharp image of an object that goes less than 5mm into the background. Using a smaller setting, like f11 and only 1-2mm of the image is clear and sharp while everything in front or in the back of this area gets more and more blurry. Is this due to the marco lens affecting the focus? For example taking a full size shot of a rose flower is next to impossible if the entire flower should be be sharp - I would like to be able to get at least 10mm of totally sharp image when using f22 settings :( If this is a downside of cheap filter lenses then I already learned my lesson, but would like to know a bit more before saving money on a dedicated macro lens that I will rarly use...

Topic by Downunder35m   |  last reply

Converting a LCD video brochure into a monitor.

I've recently found a video brochure, that consists of a 4.3" lcd display module, among other things. I'm interested in turning it into a second monitor for my computer. Is it possible to connect it through a mini-usb? (other means also welcome) Thanks oukes

Topic by Kleinkieser   |  last reply

Volt conversion with mobile charger ?

Hi, I have to DC device  a) works with 5.V    (b) 1.5 Volt...  I am using mobile charger as a power supply.  How can i connect them with one mobile the charger output is 5.V  only.  a) works fine but as the other device require 1.5 Volts . Which type of power  component should i use to supply additional appox. 1.5 Volts ? will any of these can device blast ? Any type of tips n tricks will be very help full. Thanks, Richi

Topic by RichiV   |  last reply

LilyPad Arduino USB - ATmega32U4 Board - Not detected on PC

I have a lilypad arduino usb - atmega32u4 board and when I plug in via USB on the PC (Windows 7) nothing happens. There is no sound from windows that something is connected. Nothing under Device Manager. I tried reinstalling Arduino IDE but still cannot detect the lilypad. Any suggestions what could be the problem?

Topic by SakhumziS   |  last reply

2 identical tablet batteries in parallel

Hello, is it possible to put 2 identical cube u30gt2 7.2 volt batteries in  parallel? Does the internal circuit handle it? Each battery consists of 2 3.7 volt batteries in series. thx, Mark

Topic by ComputerhulpL   |  last reply


Can anyone help me,i am looking for advise on how to patina metals,i would like to know what materials i need to start and finish a project Regards

Topic by JosephB8   |  last reply

Raspberry Pi sensing audio?

Hi all -- I have been programming all kinds of things all my life, but I have never had a chance to build a program that responds to audio input.  Suddenly: Dancing Baby Groot.  I have a great idea for an algorithm for making a very clever and funky Dancing Baby Groot using Raspberry Pi or Arduino -- if I can figure out how to get the processor to "listen" to audio input. How would I get one of those processors (or any processor) to "listen" to the mic and translate it into either digital or analog data which one could then plunder to figure out the tempo and beat in order to get Baby Groot to Dance?  I am 100% sure I can do the plundering (because it works on digital files) if I can get the processor to "listen" to the mic and create a file of numbers which represent the music being played. Any suggestions?

Topic by TheFrankTurk   |  last reply

Need to find a Controller Board kit for LG LCD display LP121SP

I have salvaged the LCD panel from an old IBM Thinkpad 570 Laptop and planning to use it with Raspberry pi. The Model and Technical details of the panel are as under: Make :                          LG LCD Inc., Korea Model Number :           LP121SP Panel Size :                  12.1 inches Dot Resolution :           800 (RGB) x 600 (SVGA) Pixel Configuration :     RGB Vertical Stripe Pixel Density :               82 PPI Aspect Ratio :               4:3 (H:V) Form Factor :               Flat Rectangle Display Pixel Pitch :                   0.3075 x 0.3075 mm (H x V) Active Area :                 246.0 x 184.5 mm (H x V) Orientation :                  Landscape type I want to convert this panel to use with Raspberry pi, but unable to find a suitable converter board kit. I have added few images also here for reference. Any help will be highly appreciated.

Topic by antoniraj   |  last reply

trouble publishing ible

Thought everything was in order.  But no success publishing.  At first, it said that none of my 3 pics was chosen as "cover pic" or somethin to that effect. But now, it just says nothin about why no publishy.

Topic by Toga_Dan   |  last reply

FEETECH 17DOF DIY humanoid robot

Https:// Feetech 17 DOF humanoid robot ready to play for education DIY FEETECH New Humanoid Robot Profile The FT-17DOF-SC-RTP is a ready to play humanoid robot which comes fully assembled & completed from our team at FEETECH. This humanoid robot uses 17PCS FT-SCServo (SCS15). SCS15 is all metal gear and uses TTL level Half Duplex Asynchronous UART BUS Communication Protocol. It gives the feedback of the data relevant to position, voltage temperature, load and speed. This humanoid robot uses all aluminum alloy parts, anodized color (red, blue, white for optional) or an assortment.It is simple wiring and makes assembly and disassembly fast and convenient. It is easy to use "MOTION" editing software for Windows system. As long as you use a computer you will love playing with this humanoid robot, even if you do not have any programming knowledge, you can edit the humanoid robot actions within ‘MOTION’ editing software. Robot hobbyist can move the robot in a variety of different poses by hand, then read in and save data from robot joint SCServo via software, moving through the posture sequences from one by one will complete the program of series motion or dance. The data of dance or motion group can be saved into your local computer for use the next time, or download into the robot control board for offline operation. The 2.4G remote control system is based on Arduino open source, users can freely modify according to our Arduino source and combination with the Robot Control Board (SCM-1) to create more advanced functions. You will feel strong & excited when to play this robot dance and movement patterns. The Robot Control Board (SCM-1) can also accept UART instructions, allowing the user to send control instructions according to the packet data’s protocol complementing the robot scope of uses and research. Humanoid Robot Specifications Height:380mm; Weight: 1.7kg(Including battery); DOF:17 Degrees Of Freedom in total Head 1 PCS Hands 6 PCS Feet 10 PCS Connect with computer:USB-mini 2300mAH NI-MH rechargeable battery and AC charger Arduino open source 2.4 G remote control system Key feature -17DOF,UART BUS servo, simple wiring, easy to assemble and disassemble -It is easy to use "MOTION" editing software for Windows system, Programmed robot’s motion by hand. -Save the robot motion data on local and is easy to be use by other robots. -Motion automatic interpolations function; Make the movement more continuous and smooth, make sure the movement of posture to posture more perfect within specified speed time. -Can name the motion group by yourself if you need great for understanding and memory. It can repeat like function calls every motion group. Each motion can be imported and exported alone. -After a series of motion group orderly arrangement can coherent form a dance. Both played online and off-line available. -Each motion group can be remote controlled by Arduino open source 2.4G remote control system (especially good for use as a fighting robot) -With 39kb FLASH motion data storage unit, can be divided into 254 motion group. If storing one motion group, It can contain up to store 730 posture. -The “MOTION” software can show motion data. The robot will to move online when double-click any data of software. This is very easy to debug robot’s motion. -Can be controlled by Arduino UART with instructions. -NI-MH battery can recharge any time no needing worry about d damage. Battery can run about 30 minutes. -Accurate design of each part. Using a screwdriver can complete the assembly Packing list One assembly completed set of FT-17DOF-SC-RTP humanoid robot including: -All metal gear SCServo * 17pcs -Aluminum alloy machinery frame * 1set -Master control board (SCM-1) * 1pcs -Arduino open source 2.4 G remote control system * 1set -7.2V 3,000mAh NI-MH battery  * 1set -8.4 V AC charger * 1pcs -USB-mini cable 150cm -Programming software “Motion”  * 1set (download from Website) Related documents -Instruction manual -Robot debugging manual -Software debugging instruction -Remote controller instruction

Topic by Robotfans 

Help! Need a tech to build a board. Schematic included

Hey all Sorry for being new to this. I was wondering if I can pay someone to make me this device Please let me know. Thanks in advance

Topic by Nuke209   |  last reply

[Help]Opening a Asus laptop charger

Hi everyone! My asus charging cord broke and i bought a replacement. However, im having trouble acutally opening the charger case/brick. I have been trying to use a screw driver to open it up, i used a hammer, a hammer and a knife but nothing =/  Anyone has any suggestions? These "methods" i tried were the ones i found on youtube and they seem to have worked in the videos but mine seems a bit more tricky.  It doesnt have any screws in sight to take off either. I attached a picture of one like it here Thanks in advance!

Topic by cyber01   |  last reply

Welcome to Super Capacitors!

First off, I know this goes to the whole front page, but this is posted in the Super Capacitor group, just so you know. Welcome to the people who joined my group! If anybody has any cool projects or ideas, please post and talk about them! Also if you know of any good deals for capacitors, please tell!

Topic by guyfrom7up   |  last reply

Ultra cheap RC quadcopter (preferably using brushed motors)

Hey everyone.... :) I'm organising a camp to encourage high school students to take up STEM courses..... and I'd like to have them build their own RC quadcopters. I want the course to have a minimal fee.... so the quad should be INSANELY CHEAP. The quad should be able to do just one thing:FLY. Also, durability is not an issue.... just one or two flights should be sufficient. 1)Can someone please suggest a design using brushed instead of brushless motors? (Simply because they're cheaper) 2)If there's any way I can build a flight controller using off-the-shelf components.... please share your ideas.. 3)I have no idea about how to make the remote control/ RF transmitter....... is it the same as that of an RC toy car remote control? 4)I've come across some lovely designs where the frame is made out of paper or cardboard.... so that's not an issue.  Help in any form is welcome.... I'd love to hear from y'all....  Thanks in advance...:)

Topic by afshaanmaz   |  last reply

inverter on a camera flash

Ive been studying the intertubes for a bit now and I cant seem to find an explanation on how a disposable camera flash works in detail. I mean I understand that it runs with two transformers, one at 300v output to charge the cap and the other to help discharge the payload through the xenon bulb run at 2000v output. but a transformer doesn't work with out a pulse or rapid continuous change in voltage. so how is it inverting to ac or am I missing something stupid

Topic by snowfox222   |  last reply

Electromagnet using permanent magnets

Hi All, I'm attempting to make a very small strong electromagnet using permanent rare earth magnets. I want to boost the magnetic field and increase the magnetic force. The magnets are 10mm in length by 5mm in radius. I have 0.4mm2 enamelled solenoid wire for the winding. My questions are, Is it possible to increase the force of a permenent  magnet? Will the induced flux into the magnet compile the force or will the EMF have to be greater to see an effect? Will paralleling two windings make the EMF stronger? As the magnets are small I have limited room to wrap windings so is there a more effective method? Any help would be great!

Topic by JimmyM5   |  last reply

Battery Powered LED Strip

Hi, I have one 6V Alkaline Battery (or two 3V Coin cell battery) that i am using to light a fairy LED strip (see here). I'd like to know for how long the battery will last me for. Can you please direct me what parameters I need to collect for the battery (or the LEDs) and what equations i will be using to determine the operating time of the battery. Thank you for your support in advance, Regards,

Topic by Greensal   |  last reply

how can one incorporate multiple USB-like connections to/from an arduino?

Hello All, I am hoping to create peer-to-peer connections (essentially a network) of multiple arduinos (or for that matter, ATMega's). However these do not have separate power supplies and each one will be powered up when connected to the other previously connected one. At the same time I would like these units to know about each other's existence when they connect (each chip should know if another chip is connected to it). I was told to think of a USB-like connection where you can share both the power and the data on the same, say, bus line. My question is how do I create multiples of this connections (more than one) and how could I make sure they work as OTG (e.g. hot plug) and can be used as both host or client at any given time? Any help is much appreciated. Thanks. Karim.

Topic by karimskarim   |  last reply

How to build a wifi or bluetooth capable button pusher for turning on computer from a distance?

I have been googleing this like crazy and cannot find anything close enough related to what I am trying to do.  I would like to be able to (ideally) use an iphone or ipad to send a wireless signal to a circuit board that then tells a piston (button pushing) mechanism to push the cylindrical on button on my computer.  It doesn't have to be a wireless signal, I could settle for less considering my lack of expertise in the area.  I am however confident in soldering and some scripting, which I thought about using a raspberry pi might work for this, especially for the wireless part of the project, but I would prefer still something with even less overhead.  If anyone has any ideas or direction that would be awesome.

Topic by zcmcc   |  last reply

Dropbox application in background process on OpenWRT processor of my Arduino Yun.

Hello everybody, Simple question: does the Arduino YUN support the same DROPBOX functionalities as my laptop? Basically, I need to download data from the SD card of my Arduino Yun to my application server. But the internet connection of my Arduino is not very stable. How I want it to work: 1.    I have a sketch that writes data on a TXT file to my SD card every 10 minutes 2.    I want to install Dropbox on my Arduino Yun 3.    Then, whenever the Yun is connected, it will synchronize all the files from the SD Card with my Dropbox folder on my server. That would happen (I guess) in the background, without my Arduino needing to run a sketch. To do that, I think I need drobox to run ‘in the background’ on my Arduino microprocessor. Did anyone do this before? Thanks. What does NOT work: Initially, I used the "LogToDropbox" sketch inserted in the "Datalogging to Dropbox with Arduino Yun" tutorial at the following link: in order to ‘actively’ upload files to my Dropbox app console from my SD card with an internet connection. But if , my Arduino Yun is losing the internet connection, it is impossible to upload the files created during the downtime to my Dropbox app console. These files are stored on the SD card plugged on the Yun during this time interval, but not synchronized.

Topic by DELETED_jay97430 

arduino uno

Good morning I am getting the arduino uno with the monitor. Want to have 5 booton and clicking individually to my display a MESSAGE on the screen when the potato and when let off. these be in the second row while the first shows to permanently temperature from someone sensor someone can help. thanks

Topic by ssakiss1   |  last reply

IRCF 360 like 3d Motion sensor

I want to make my own VR system. I'll be making an oculus rift like VR headset (courtesy: a brilliant instructable called Nova) but I need help making a 3D motion sensor. Looked for many options but finally settled for IRCF 360 but the problem is there are not yet selling the sensor. So if anyone has any idea how to make one like it, please help. Thanx. Here is the link for reference-

Topic by VirajS1   |  last reply

Walking/Marquee effect for LED Strip

I'm trying to achieve a "walking-type" effect also called marquee-effect using individually wired LEDs, so that it seems the lights are moving from one end to the other. Here's a video for reference: It is easy enough if we have repetition every 3 LEDs. But my restriction is that I have repetition every 2 LEDs. The circuit is something like the one in the diagram(pardon my MS Paint skills): Every other RGB LED is connected together.  One simple way to provide the effect is to show color1 in LEDs at odd position and color2 in LEDs at even positions and then switch them. This is different from a similar effect in cheap fairy lights as I can set the color and intensity of the LEDs besides just on/off... Here is a GIF of my attempt of simple color switching with an addressable LED strip for now: In this, I cannot set any direction of travel and the effect depends on using a bit of imagination... Although it might seem difficult to provide a good effect with just 2 color channels, I want an opinion if it is possible or not?

Topic by Antzy Carmasaic   |  last reply

Bug Report

When i login to the instructable app (version:2.0.4) from my android phone of jelly bean version 4.2.1, It shows I haven't published any article, But i have already published 2 articles. And another problem is, in the side bar of the app, it shows both login and logout option. I have attached the screen shot, see it below. It is showing 0 favourites, 0 following only in app. But when I login in browser it shows correctly. I have around 30 favourites and I am following some authors. But in the app it is not showing correctly.

Topic by Invento Guy   |  last reply

how to build simple programable 2 function ( head pan and tilt) pilot figure for rc airplanes

Hi, I'm completely new to animatronics bot have been designing, building and flying RC airplanes for 40 or more years, I need some help with a project, namely, I wish to build an animatronic pilot figure for a large 1/3 scale airplane and would like it to be programmable so that once it is turned on, it will carry out a series of movements over and over until switched off.    These would be a combination of head pan and tilt that I could program into the system, the mechanical side of things is simple enough, a 2 servo camera gimbal but I need help with the electronic side of things..............can anybody help ??? 

Topic by Babyace   |  last reply

How make a waterbird (pumpabike)

I am an Engineering science student doing my fifth year at Technology University in Vietnam. Part of our studies involves a final year project, and I have selected one on building a water craft similar in principle to the waterbird. Part of this project will primarily involve modelling this craft, how it works, simulation operation, structure analysis. Ultimately we will build a full size craft and test the design. However, some problems in structure and operating priciples which i don't understand, such as: - Properties spring? - Why they choose NACA 63-412? - time of a cycle action (jump down--> jump up) and amplitude ( only consider rear wing)? - properties aluminium used? Please answer some question? Capacity of English is bad. So, I don't clearly describle my desires. I hope you will sympathize. Very thanks! I hope you will answer in short time!

Topic by quangtruc106   |  last reply

SSR and a hotplate

Dumb question. Have a heating plate that uses 1100 watts and runs on 120 volts ac. if 1100 watss / 120 volts = more or less 10amps, Could I safely use a 10 amp rated ssr aka solid state relay or use something higher.

Topic by Computothought   |  last reply

Paracord Kits

Hey there, I offer a variety of different Paracord Kits on my website. You can find them here: Use my Instructables I offer here to accompany your paracord kit projects. I currently offer: Bracelet kits Keychain kits Lanyard Kits Checkout securely using Paypal, or any Credit/Debit. If anyone is interested in trading I could do that too! Anthony

Topic by AnthVale   |  last reply

Leonardo - Warning System + Voice Recognition

I designed and built a warning system, using 3 sensors, that detect when an object is approaching. The system also has a toggle switch and a buzzer. When the toggle switch is in the OFF position: If there are no objects nearby the LED turns GREEN, if either sensor 1 or 3 detect an object the LED turns YELLOW and finally if the object is between sensors 1 and 2 or 2 and 3 the LED turns RED. When the toggle switch is in the ON position:  Same as OFF position + buzzer  beeping depending on color of LED. Now I would like to add voice recognition to my system. I purchased a JY-MCU Bluetooth Wireless Serial Port Module and was able to test it using a simple program that changed the color of my LED depending on the command I gave it using my phone. My problem now is that whenever I tried to add the voice recognition capability to my warning system its not working. The code I'm using makes sense but I'm new at this so I might be missing something. I'll be posting 3 codes: 1)Warning System 2)Test for Voice Recognition 3) Current non-working code.

Topic by c_MOS   |  last reply


Getting laptop to stream to ecm in car

Topic by clamp   |  last reply

Samsung lcd bad cap problems

Hey guys, recently I scored a Samsung 943nw monitor from my friend who says it's broken. So i thought, why not try repair it? Upon opening the lcd monitor up, I can see that the caps were bulging, samwha brand. The infected caps were three 25v 820µF and two 10v 1000µF. I went and sourced the caps from a couple of devices (a modem, and a power supply) When I turned the lcd on, the led was blinking. After the repair(with my crappy soldering skills), the monitor turned on, but not the backlight. I figured that the cc backlight inverter was spoiled. Then, after a probing at the components, I reset the monitor in hopes that the inverter would work. Instead, now the monitor showed no signs of life. Probing again showed that the 5v rail was 8.45v and 15v rail was 4.5v and 3.3v was ov. I still can't find the problem after hours of searching. (and a fatal electrocution from the mains input cap). Could it be my bad soldering, parts or some transistor problem? DId I also accidentally fry the image processing module?

Topic by Phoenix Tech   |  last reply

First robotics

Hi im lego man from team 60 and i set up this form topic for people to see who from instructables is on a First robotics team. you can also post your questions here too. See the group:first robotics

Topic by Lego man   |  last reply

want to add built-in bluetooth audio receiver to an active Speaker

I like to add a bluetooth audio receiver to a Sonos Active speaker. I would like to build it inside the speaker so it looks nice too. I assume I have to get one of the Bluetooth Audio receiver boards like this . I think I should be able to find a 5volt connection somewhere in the Sonos speaker to power this unit and then have to hook it up to the AUX connection in parallel to get the audio going.  I was wondering if someone knows of a good bluetooth audio adapter that can pair multiple devices.  Also any other ideas or suggestions would be appreciated.  Thanks

Topic by nashmarkt   |  last reply