Pico-PIO-USB

USB host/device implementation using PIO of raspberry pi pico (RP2040).

You can add additional USB port to RP2040.

Demo

https://user-images.githubusercontent.com/43873124/146642806-bdf34af6-4342-4a95-bfca-229cdc4bdca2.mp4

Project status

Examples

• host_hid_to_device_cdc.c which print mouse/keyboard report from host port to device port's cdc. TinyUSB is used to manage both device (native usb) and host (pio usb) stack.
• usb_device.c is a HID USB FS device sample which moves mouse cursor every 0.5s. External 1.5kohm pull-up register is necessary to D+ pin (Default is gp0).

cd examples
mkdir build
cd build
cmake ..
make
# Copy UF2 file in capture_hid_report/ or usbdevice/ to RPiPico

Another sample program for split keyboard with QMK

https://github.com/sekigon-gonnoc/qmk_firmware/tree/rp2040/keyboards/pico_pico_usb

Resource Usage

• 1 PIO, 3 state machines, 32 instructions
• Two GPIO for D+/D- (Series 22ohm resitors are better)
• 15KB ROM and RAM
• (For Host) One 1ms repeating timer
• (For Device) One PIO IRQ for receiver