This is my own version of the “USB IR Toy” by Ian (dangerousprototypes.com). It has the same features and can run the same programs and bootloader. Fortunately, the USB IR Toy is open-source, and you can get the code from the google code page of “dangerous prototypes”.
As Ian gives the schematics of his project, I was able to adapt it to my desires. The improvements compared to theoriginal design are below :
- Smaller than the original USB IR Toy
- Full integration in a tiny case (the case external width and length are almost exactly the same as the printed circuit board of the USB IR Toy)
- Four LEDs for increased range
- And it can be powered with a 9V battery, making it independant of the computer.
There is a push-button and a normal LED on the top of the box. The push-button is connected to the MCLR pin of the PIC so it resets the microcontroller. But you can desactivate the MCLR pin in the code and use it to trigger other events…
Look at the following for some pictures, schematics and more :
With the case opened :
On the back side you can see the 5V regulator and the 2 transistors that drive the 4 IR LEDs :
Here is the schematic (In fact, I added a few capacitors next to the PIC and next to the IR receiver afterwards).
- As PNG images : schematics and PCB : top layer, bottom layer, and both
- Sources for PROTEUS : ISIS (schematics) and ARES (PCB)
- PDF ready to be printed to reproduce the PCB
Here is were you can obtain the main components :
- PCB : home-made (double-sided but not very difficult)
- Microcontroller PIC18LF2550 or 18F2550 (available for free on the microchip website as a sample : just create an account)
- IR LEDs : purchased on www.led1.de (6€ for 10 pieces)
- IR receiver : obtained from seeedstudio (0.75USD)
- 5V regulator : I used a LDO 1117, because I had one lying around
- Transistor for driving the IR LEDs : FMMT617 (capable of driving a high current : up to 3A!! You can change the resistors and your IR LEDs to increase the current through them and consequently the range) from Farnell
- 18*40*28 case from Farnell, ref 117-1583, 1.15€
All in all, the whole project is really cheap.
I plan to use it as a beacon for a small robot (that is why I needed it to be powered without a computer). I will give the program as soon as it is working well enough.
Feel free to ask questions and give your thoughts on the coms or by sending an e-mail.