USB Infrared Toy through-hole version
This design is the next-gen USB IR Toy v1.1 circuit rearranged into a through-hole PCB. It's the basic IR Toy v1 with a couple additions:
- Raw infrared signal detector for frequency measurement
- Breakout area with all the unused pins, tap in and do something interesting
Seeed has the PCB available for $7, but you'll need to get your own parts. The through-hole PIC is so expensive we don't plan to make a kit.
Click for a full size schematic image. Schematic and PCB were designed with the freeware version of Cadsoft Eagle.
- The latest IR Toy though-hole version (USBIRtoy.v2x-PTH) schematic and PCB are available here.
- Get the latest IR Toy firmware is from our GitHub download page.
See the original USB Infrared Toy how-to for a complete overview of the circuit. We’ll just highlight the changes here.
The major update in this design is the addition of a raw infrared sensor. The original IR Toy has an IR demodulator that turns infrared encoded pulses into 1s and 0s. The new design also has QSC159 IR sensor that passes the raw IR signal directly to the PIC for measurment and analysis.
The QSC159 gets a 0.1uF coupling capacitor (C7) on the 5volt power supply. The output is open collector, meaning it can’t create a high output on it's own, so we use pull-up resistor R6 (10K) to hold the pin high.
The IR detector connects with two PIC pins. One has a hardware CCP module that measures the width of each infrared pulse. The other has a counter that tracks the total number of ticks in each infrared transmission. The raw signal data can be extracted from the IR sample mode.
Unused pins are connected to a small breakout area. Unfortunately we did not connect the internal signals (IR RX, IR TX, IR Detect) to the header, this may be updated in a future batch of PCBs.
The PIC USB interface has an internal 3.3volt regulator that needs a 0.22uF capacitor. 0.1uF is a much more common value, so the production board (seen below) has two capacitor footprints (C2, C3) connected to the USB regulator. If you don't have a 0.22uF capacitor, just use two 0.1uF capacitors.
Click for a full size placement image.
|ICSP||1||1X05 pin header||1X05|
|TX||1||5MM IR LED||-|
|USB||1||USB B connector||-|
Get the latest IR Toy firmware from our GitHub download page.
- The regular USB IR Toy firmware since v09 has full support for the frequency detector.
- Works with or without a bootloader (can be programmed directly with a ICD, PICkit, etc)
The virtual serial port (CDC) is an open standard, it should work on any modern operating system.
You don't need a driver, but you will need a .inf file to tell Windows how to use the device. A suitable .inf is included in the firmware download.
Using the bootloader
The bootloader is optional, but an easy way to update without dragging out a programmer. See the detailed PIC programming guide for help installing the bootloader.
- Get the bootloader.hex file from the latest firmware download
- Connect a PIC programmer to the 5 pin ICSP header on the breakout area
- Program the bootloader with the programmer
- Bootload the latest firmware over USB with the normal IR Toy update instructions.