The is the variant of the MiSTeryNano FPGA companion firmware for the Raspberry Pi Pico (W).
sudo apt install cmake gcc-arm-none-eabi libnewlib-arm-none-eabi build-essential
sudo dnf group install "development-tools"
sudo dnf install clang cmake gcc-arm-linux-gnu arm-none-eabi-gcc-cs-c++ arm-none-eabi-gcc-cs arm-none-eabi-binutils arm-none-eabi-newlib
Download the Raspberry Pi Pico SDK
and set the PICO_SDK_PATH environment variable to point to the
SDKs root directory.
git clone https://github.com/raspberrypi/pico-sdk --recursive
export PICO_SDK_PATH=<full-path-to-clones-sdk>
The TinyUSB inside the Pico SDK needs to be at least version 0.17.0.
To update it go to pico-sdk/lib and install PIO-USB do:
cd pico-sdk/lib
mv tinyusb tinyusb.old
git clone https://github.com/hathach/tinyusb.git
cd tinyusb
python3 tools/get_deps.py rp2040
This repository has to be cloned recursively to make sure the submodules are included.
git clone https://github.com/harbaum/FPGA-Companion.git --recursive
cd FPGA-Companion
Alternally do a
git submodule update --init
after a non-recursive clone to update the submodules.
To start the build process create a build directory and start the compilation:
cd src/rp2040
mkdir build
cd build
cmake ..
make
The resulting file named fpga_companion.uf2 is loaded onto the
Pico as usual. Once successfully booted the Pico's LED will blink.
Additional debug output is sent via UART at 921600 bit/s on GP0 on a regular Pi Pico or Pico(W) and at 460800 bit/s on Waveshare RP2040-Zero.
| Pin | Signal | Description |
|---|---|---|
| GP0 | UART_TX | Serial debug output |
| GP2 | USB D+ | USB PIO host D+ |
| GP3 | USB D- | USB PIO host D- |
| GP16 | MISO | SPI data from FPGA |
| GP17 | CSn | SPI chip select to FPGA |
| GP18 | SCK | SPI clock to FPGA |
| GP19 | MOSI | SPI data to FPGA |
| GP22 | IRQn | SPI interrupt from FPGA |
The RP2040 can use the pins GP2 and GP3 for a USB host port as depicted below. This is the default configuration for the FPGA Companion, although it's possible to use the standard on-board micro USB connector instead.
To do so in the file tusb_config.h the PIO USB
needs to be disabled by setting the following value
to 0:
// change to 0 if using on-board native micro USB
// change to 1 if using pico-pio-usb as host controller for raspberry rp2040
#define CFG_TUH_RPI_PIO_USB 1
To use this you need a micro-USB to USB-A-OTG adapter.
The Raspberry Pi Pico is rather big and only comes with a Micro USB port. The Waveshare RP2040-Zero is a little smaller and comes with a USB-C connector which makes it easier to use it as a USB host using a regular USB-C to USB-A host adapter.
To build the firmware for the RP2040-Zero use the following command:
cmake -DWS2040_ZERO=ON ..
The build process will then end with the following message:
Firmware has been built for Waveshare RP2040-Zero.
The SPI pins used on the RP2040-Zero differ from the ones used on the regular pico:
| Pin | Signal | Description |
|---|---|---|
| GP0 | UART_TX | Serial debug output |
| GP4 | MISO | SPI data from FPGA |
| GP5 | CSn | SPI chip select to FPGA |
| GP6 | SCK | SPI clock to FPGA |
| GP7 | MOSI | SPI data to FPGA |
| GP8 | IRQn | SPI interrupt from FPGA |
Also the RP2040-Zero comes with a WS2812 RGB led instead of a regular LED. Driving the RGB LED requies a PIO unit and thus cannot be used at the same time as the PIO-USB. The native USB of the RP2040-Zero must therefore always be used, anyway.
The RP2040 is by default somewhat inconvenient to develop for as it has to be mounted manually as mass-storage to copy the uf2 file onto it.
It's thus recommended to use a second Pi-Pico as a SWD programming
adapter. The details are explained in appendix A of
Getting started with Raspberry Pi Pico under section Debug with a second Pico.
The CMakeLists.txt file already contains a matching target and
with openocd installed a simple make flash should upload the
new firmware via the second Pico.