WALL-F Junior Base Stack

Start System

SSH into RPI terminal and execute: ./system_rpi.sh

On base station terminal execute: ./system_base_station.sh

Hardware Connection

Rear Driver Motor Driver (L298N)

• 12V -> Battery pack +
• GND -> Battery pack - & Pico rear GND
• ENA -> Pico rear GP6
• IN1-> Pico rear GP7
• IN2-> Pico rear GP8
• IN3-> Pico rear GP9
• IN4-> Pico rear GP10
• ENB-> Pico rear GP11

Soil Moisture Sensor Stepper Motor Driver (A4988)

• VM-> Battery pack +
• GND (bellow VM) -> Battery pack -
• 1B, 1A, 2A, 2B -> Servo motor 4 pin plug, order doesn’t matter
• VDD -> Pico rear 3V3(OUT)
• GND (bellow VDD) -> Pico rear GND
• MS2 -> Pico rear 3V3(OUT)
• RST & SLP -> Jumped together with jumpers
• STEP -> Pico rear GP12
• DIR-> Pico rear GP13

Soil Moisture Sensor

• Red wire -> Pico rear ADC_VREF
• Black wire -> Pico rear AGND
• The one that is not black nor red -> Pico rear GP26

Air Sensor (BME680)

• 2-5V -> Pico rear 3V3(OUT)
• SDA -> Pico rear GP2
• SCL -> Pico rear GP3
• GND -> Pico rear GND

Left Joint Stepper Motor Driver (A4988)

• VM-> Battery pack +
• GND (bellow VM) -> Battery pack -
• 1B, 1A, 2A, 2B -> Servo motor 4 pin plug
• VDD -> Pico front 3V3(OUT)
• GND (bellow VDD) -> Pico front GND
• MS2 -> Pico front 3V3(OUT)
• RST & SLP -> Jumped together with jumpers
• STEP -> Pico front GP6
• DIR-> Pico front GP7

Right Joint Stepper Motor Driver (A4988)

• VM-> Battery pack +
• GND (bellow VM) -> Battery pack -
• 1B, 1A, 2A, 2B -> Servo motor 4 pin plug
• VDD -> Pico front 3V3(OUT)
• GND (bellow VDD) -> Pico front GND
• MS2 -> Pico front 3V3(OUT)
• RST & SLP -> Jumped together with jumpers
• STEP -> Pico front GP8
• DIR-> Pico front GP9

IMU (GY-521)

• VCC -> Pico front 3V3(OUT)
• GND -> Pico front GND
• SCL -> Pico front GP3
• SDA -> Pico front GP2

First Section Driver Motor Driver (L298N)

• 12V -> Battery pack +
• GND -> Battery pack - & Pico first GND
• ENA -> Pico first GP6
• IN1-> Pico first GP7
• IN2-> Pico first GP8
• IN3-> Pico first GP9
• IN4-> Pico first GP10
• ENB-> Pico first GP11

5V Regulator

• IN+ -> Battery pack +
• IN- -> Battery pack -
• OUT+ -> Pico first VSYS, Pico rear VSYS & Pico front VSYS
• OUT- -> Pico first GND, Pico rear GND & Pico front GND

Raspberry Pi

• GND -> Pico rear GND & Pico front GND
• GPIO4 -> Pico first GP1
• GPIO5 -> Pico first GP0
• GPIO8 -> Pico rear GP1
• GPIO9 -> Pico rear GP0
• GPIO12 -> Pico front GP1
• GPIO13 -> Pico front GP0

Software Installation

Install Ubuntu

Install Ubuntu Desktop 24.02.2 LTS (64-bit) to Raspberry Pi 4 boot SD card using Raspberry Pi Imager

sudo apt update
sudo apt upgrade
sudo apt install vim

Enable SSH (Raspberry Pi Only)

sudo apt install ssh
sudo systemctl enable ssh

Install ROS

Install ROS 2 Jazzy following official installation guide.

echo "source /opt/ros/jazzy/setup.bash" >> ~/.bashrc
sudo rosdep init
rosdep update

Adjust CSI Camera Permissions (Raspberry Pi Only)

sudo vim /etc/udev/rules.d/raspberrypi.rules
# SUBSYSTEM=="dma_heap", GROUP="video", MODE="0660"
sudo udevadm control --reload-rules && sudo udevadm trigger
sudo usermod -a -G video $USER

Enable Additional UART (Raspberry Pi Only)

sudo usermod -a -G dialout $USER
sudo vim /boot/firmware/config.txt

Add the following lines and reboot:

enable_uart=1
dtoverlay=uart3
dtoverlay=uart4
dtoverlay=uart5

Install Dependencies of Raspberry Pi Pico C/C++ SDK

sudo apt install cmake gcc-arm-none-eabi libnewlib-arm-none-eabi libstdc++-arm-none-eabi-newlib

Build

git clone --recurse-submodules https://github.com/noidvan/wall_f_junior_base_stack
cd wall_f_junior_base_stack
rosdep install --from-paths src --ignore-src -r -y
colcon build

Flash Pico

• After compilation, locate front_agent.uf2, rear_agent.uf2 and first_section_agent.uf2 in build/wall_f_junior_pico.
• Press and hold the BOOTSEL button on the Pico while plugging in its USB to the computer.
• Copy the .uf2 file for the corresponding Pico into the appeared drive

Credits

This project contains code from the following open-source releases:

• ROS 2 node for libcamera by Christian Rauch under the MIT license
• micro-ROS Agent by Open Robotics under the Apache-2.0 license
• Autonomy Stack by Prof. Ji Zhang
• micor-ROS Raspberry Pi Pico SDK by Open Robotics under the Apache-2.0 license
• Raspberry Pi Pico SDK by Raspberry Pi under the BSD-3-Clause license
• Pico BME688 by bablokb