Raspberry Pi PIO Installation Guide

You may want to do PlatformIO work from a Raspberry Pi. Here is a Installation Guide!

Here is a complete, step-by-step guide to install PlatformIO (PIO) on your Raspberry Pi 4 (running Raspberry Pi OS) and use it to flash the PJ26 (STM32F103C8T6) + DX-LR20 board, following the instructions from the NeutralSystem/STM32_DX-LR20_LORA repository.

Step 1: Update Your Raspberry Pi OS

Run these commands first:

sudo apt update && sudo apt upgrade -y
sudo apt install -y python3 python3-pip python3-venv git curl libffi-dev libssl-dev

Step 2: Install PlatformIO Core (CLI) on Raspberry Pi

PlatformIO works well on Raspberry Pi 4 via its Python-based installer. Use the official installer script for the most reliable setup:

# Run the official PlatformIO installer
python3 -c "$(curl -fsSL https://raw.githubusercontent.com/platformio/platformio-core-installer/master/get-platformio.py)"

# Add PlatformIO to your PATH (permanent)
echo 'export PATH="$HOME/.platformio/penv/bin:$PATH"' >> ~/.bashrc
source ~/.bashrc

Note: The above did not actually work, we ended up using wget, then python3 as in:

wget https://raw.githubusercontent.com/platformio/platformio-core-installer/master/get-platformio.py
python3 get-platformio.py

Verify the installation:

pio --version

You should see the PlatformIO version printed. If the command is not found, log out and log back in (or run source ~/.bashrc again).

Alternative (pip method) – if the script fails:

pip3 install -U platformio

Some Diagnostic Screenshots

Step 3: Grant Serial Port Permissions

The flashing process uses a USB-to-serial adapter connected to the STM32’s UART (PA9/PA10). Add your user to the dialout group:

sudo usermod -a -G dialout $USER

Reboot the Raspberry Pi or log out and log back in for the group change to take effect.

sudo reboot

Step 4: Prepare Hardware for Flashing

Connect USB-to-Serial adapter (3.3 V logic only!):

• Adapter TX → STM32 PA10 (RX)
• Adapter RX → STM32 PA9 (TX)
• Adapter GND → STM32 GND
• Do not connect 5 V to the board.

Put the STM32F103 into bootloader mode (if required by your board):

• Some PJ26/DX-LR20 boards have a BOOT0 jumper or button. Set BOOT0 high and reset the board.
• The project supports serial upload via the built-in bootloader.

Identify the serial port (usually /dev/ttyUSB0 or /dev/ttyACM0):

ls /dev/ttyUSB* /dev/ttyACM*

Step 5: Clone the Repository and Flash the Firmware

git clone https://github.com/NeutralSystem/STM32_DX-LR20_LORA.git
cd STM32_DX-LR20_LORA

Build the firmware:

pio run

Flash (upload) to the board:

pio run --target upload

PlatformIO will automatically detect the serial port in most cases. If it fails to detect, specify the port explicitly by editing platformio.ini or using:

pio run --target upload --upload-port /dev/ttyUSB0

Step 6: Verify the Flash

1. After flashing, reset the board.
2. Open a serial terminal on the Raspberry Pi (115200 baud):

sudo apt install -y minicom
minicom -b 115200 -D /dev/ttyUSB0

(Replace /dev/ttyUSB0 with your actual port.)

1. You should see a > prompt. Type help to list available CLI commands (status, LED blink, register dump, send ping, RSSI, etc.).

Troubleshooting Common Issues on Raspberry Pi

• Command 'pio' not found: Run source ~/.bashrc or reboot.
• Permission denied on serial port: Ensure you are in the dialout group (groups | grep dialout).
• Upload fails / no port detected: Manually specify --upload-port /dev/ttyUSB0. Try different USB ports or adapters.
• Toolchain download slow or fails: PlatformIO downloads the ARM GCC toolchain on first build. Ensure a stable internet connection.
• 32-bit vs 64-bit Raspberry Pi OS: Both should work, but 64-bit (aarch64) is recommended on Pi 4. Some older toolchains may need extra time on first run.
• Board stays in bootloader: Double-check BOOT0 pin state and reset timing.

Next Steps After Flashing

Once the firmware is loaded:

• Use the diagnostic C program from the previous response (the one that sends CLI commands over serial) to test STM32 health, read LLCC68/SX1262 registers, perform RSSI checks, and run ping tests.
• The firmware provides a rich CLI for LoRa operations, including packet send/receive, spectrum scan, and more.

Would you like me to provide:

• An updated version of the Raspberry Pi diagnostic program tailored to the exact CLI commands in this firmware?
• Instructions for modifying platformio.ini (e.g., to force a specific upload port)?
• Guidance on building a HEX file for alternative flashing tools (MCU ISP / ST-Link)?

Let me know the exact serial port you see (ls /dev/tty*) or any error messages you encounter during installation or flashing, and I will provide precise fixes.