ros2_mqtt

A ros2 node that listens to teleop_twist message and publishes to mqtt topic

on computer

pre-requisite is to install paho mqtt client like this: pip install paho-mqtt

update configurations in following places

1. in ros2_mqtt/config/param.yaml file - replace 192.168.1.123 with ip address of where you are running mqtt broker [your computer]
2. in esp32/boot.py - update SSID and PWD for your wifi
3. in esp32/main.py - replace IP_ADDR_OF_MQTT_BROKER with your mqtt broker ip address [same as ####1]

build the project from root folder of workspace

colcon build

launch the ros2mqtt node along with teleop twist nodes

ros2 launch ros2_mqtt ros2_mqtt.launch.py

show twist messages

ros2 topic echo /cmd_vel

show mqtt messages

mosquitto_sub -v -t 'esp32/cmd_vel'

restart mqtt broker

sudo systemctl stop snap.mosquitto.mosquitto.service sudo systemctl start snap.mosquitto.mosquitto.service

on ESP32

install Thonny and set interpreter to esp32

connect esp32 via usb to your computer

install esptool and flash micropython on esp32

upload boot.py and main.py files on esp32 and connect with esp32 again

you should be able to send twist messages using joystick and should be able to confirm

those messages are being published to mqtt topic by subscribing to mqtt topic

and looking at the console log on Thonny where esp32 will log same messages