senden9 / Pico-PIO-USB

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

Pico-PIO-USB

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

You can add additional USB port to RP2040.

🚧 This library is WIP. API may be changed drastically in future. 🚧

Demo

demo.mp4

Project status

Planned Features	Status
FS Host	✔
LS Host	✔
Hub support	✔
Multi port	✔
FS Device	✔

Examples

• capture_hid_report.c is a USB host sample program which print HID reports received from device. Open serial port and connect devices to pico. Default D+/D- is gp0/gp1. Call pio_usb_add_port() to use additional ports.
• 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 example
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

• Two PIO
  • One PIO is for USB transmitter using 22 instruction and one state machine
  • Another PIO is for USB receiver using 31 instruction and two state machine
• 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