Using Raspberry pi as JTAG Programmer For WIO Tracker 1110

Introduction

In this project, we'll use a Raspberry Pi as a cost-effective SWD (Serial Wire Debug) debugger and programmer for WIO Tracker 1110, where we can flash bootloader to the dev board. We'll utilize OpenOCD and `adafruit-nrfutil` to achieve this. This guide will walk you through the entire setup process, from wiring to programming your microcontroller using a hex file.

Prerequisites

• Raspberry Pi Zero W
• WIO Tracker 1110
• Jump Wires: To connect the Raspberry Pi GPIO pins to the SWD interface of WIO Tracker 1110.
• Software: OpenOCD, `adafruit-nrfutil`, and necessary dependencies.

Stage 1: Install Software

Step 1-1: Add Swap

• Create a swap file:

sudo dd if=/dev/zero of=/swapfile bs=1M count=2048

• Set the correct permissions for the swap file:

sudo chmod 600 /swapfile

• Set up the swap space:

sudo mkswap /swapfile

• Enable the swap space:

sudo swapon /swapfile

Step 1-2: Install Dependency

• Update and Upgrade your Raspberry Pi

sudo apt update
sudo apt upgrade

• Install Dependencies

sudo apt install libtool libftdi-dev libusb-1.0-0-dev gcc-arm-none-eabi binutils-arm-none-eabi build-essential make libusb-dev libgpiod-dev

Note: This install steps will take sometime.

Step 1-3: Install OpenOCD

OpenOCD is an open-source tool for programming and debugging ARM-based devices. Install it on your Raspberry Pi using the following steps:

• Download and Install OpenOCD

sudo apt install openocd

Step 1-4: Setup Python Environment

To set up a Python environment and activate it, you can follow these steps:

• Create a virtual environment:

python3 -m venv adafruit-nrfutil

• Activate the virtual environment:

source adafruit-nrfutil/bin/activate

Step 1-5: Python Denpendency

`adafruit-nrfutil` is used for handling Nordic Semiconductor’s nRF series of Bluetooth Low Energy (BLE) modules.

• Install the adafruit nrf utility

pip install adafruit-nrfutil

• To install the Intelhex package

pip install Intelhex

Stage 2: Build WIO Tracker WM1110 Bootloader

Step 2-1: Clone the Adafruit nRF52 Bootloader repo

• Clone the Milk-V-M/Adafruit_nRF52_Bootloader github repo

git clone https://github.com/Milk-V-M/Adafruit_nRF52_Bootloader.git
cd Adafruit_nRF52_Bootloader
git submodule update --init

Step 2-2: Make the Bootloader Firmware

• Then build it with make BOARD={board} all:

make BOARD=wio_tracker_wm1110 all

now you should get a folder with the bootloader firmware in _build folder like:

cd ~/Adafruit_nRF52_Bootloader/_build/build-wio_tracker_wm1110

Stage 3: Flashing

Step 3-1: Wiring Connections

First, connect the GPIO pins of the Raspberry Pi to the SWD pins of the microcontroller. Here is the wiring diagram:

Ensure that the power supply voltage levels are compatible between the Raspberry Pi and the microcontroller.

Step 3-2: Configure OpenOCD for SWD

Create a custom configuration file for OpenOCD to use the Raspberry Pi as an SWD adapter:

• Create the Configuration File

sudo nano /etc/openocd/custom_swd.cfg

• Add the following configuration

adapter driver bcm2835gpio
bcm2835gpio peripheral_base 0x3F000000
bcm2835gpio speed_coeffs 146203 36

adapter gpio swclk 11
adapter gpio swdio 25
adapter gpio srst 24

transport select swd

adapter speed 100

set WORKAREASIZE 0x4000

source [find /usr/share/openocd/scripts/target/nrf52.cfg]

Step 3-3: Running OpenOCD

• Run OpenOCD with the custom configuration file:

sudo openocd -f /etc/openocd/custom_swd.cfg

If everything is set up correctly, OpenOCD should initialize and connect to your target microcontroller using SWD.

Step 3-4: Upload Firmware via OpenOCD

• Use the following command to upload the firmware to the microcontroller:

cd ~/Adafruit_nRF52_Bootloader/_build/build-wio_tracker_wm1110

sudo openocd -f /etc/openocd/custom_swd.cfg -c "program your_firmware.hex verify reset exit 0"

Replace `your_firmware.hex` with the path to your extracted firmware file.

• For my case eg:

sudo openocd -f /etc/openocd/custom_swd.cfg -c "program wio_tracker_wm1110_bootloader-366a3b9-dirty.hex verify reset exit 0"

(Optinal)Step 3-5: Using GDB for Debugging

You can use `arm-none-eabi-gdb` or another GDB client to connect to OpenOCD and debug your application:

arm-none-eabi-gdb your_program.elf
(gdb) target remote localhost:3333

This will connect GDB to OpenOCD, allowing you to set breakpoints, step through code, and inspect memory and registers.

Troubleshooting

• Connection Errors: Double-check wiring and ensure GPIO pins are correctly mapped.
• Permission Issues: Ensure you run OpenOCD with `sudo` to access GPIO pins.
• Compatibility: Verify the target configuration file matches your microcontroller.

Conclusion

Using a Raspberry Pi as an SWD debugger and programmer provides a powerful and flexible solution for embedded development, offering both debugging capabilities and ease of firmware management for nRF52 microcontrollers. With OpenOCD and `adafruit-nrfutil`, you have a robust setup for your development needs.

Feel free to ask questions or share your experiences in the comments below!

Reference:

https://linuxjedi.co.uk/2020/12/01/programming-xilinx-jtag-from-a-raspberry-pi/

https://forums.raspberrypi.com/viewtopic.php?t=353015