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Published January 30, 2024 © Apache-2.0

Micro ros on ESP32 using arduino IDE

In this tutorial you will learn how to connect ESP32 with micro-ROS and ROS 2. You will also learn how to install micro-ROS agent in Linux.

IntermediateProtip8,078

Things used in this project

Hardware components

USB-A to Micro-USB Cable

Espressif ESP32

ESP32 development board

Software apps and online services

ROS Robot Operating System

Arduino IDE

micro-ROS

Ubuntu 22.04

Story

Micro-ROS puts ROS 2 onto microcontrollers. In ROS2 micro-ROS is used for connecting microcontrollers to ROS2. This documentation aims to help to getting start with micro-ROS in ESP32 using arduino IDE. We will try to make it simple, you can also visit the micro-ROS official documentation

Different methods available for compiling and uploading micro-ROS libraries to ESP32. Here in this tutorial we are using arduino IDE. You will learn to connect ESP32 and micro-ROS agent. Also how to install micro ros agent on Ubuntu.

In ROS1 rosserial is the library used for connecting microcontroller and ROS. Read difference between micro-ROS and rosserial for more details.

System specification

Ubuntu 22.04 and ROS2 humble

Development Board used : DOIT ESP32 DEVKIT

Installation micro-ROS agent

Install ROS2 humble by following the instructions on official documentation.

Open the terminal and excecute the following commands

Set up your environment by sourcing the following file.

source /opt/ros/humble/setup.bash

For using ROS2 commands you need to run source /opt/ros/humble/setup.bash everytime when you open a new terminal for avoiding this we can put the source command on bashrc file. Commands inside bashrc is excecuted everytime when you open a new terminal

For opening .bashrc j:

gedit ~/.bashrc

Add the following command to this file

source /opt/ros/humble/setup.bash

Create a workspace and download the micro-ROS tools:

cd
mkdir microros_ws
cd microros_ws

Cloning micro-ROS src file from github

git clone -b $ROS_DISTRO https://github.com/micro-ROS/micro_ros_setup.git src/micro_ros_setup

Installing rosdep

sudo apt install python3-rosdep2

Update dependencies using rosdep

sudo apt update && rosdep update
rosdep install --from-paths src --ignore-src -y

Install pip

sudo apt-get install python3-pip

Build micro-ROS tools and source them

colcon build
source install/local_setup.bash

To install the micro-ros Agent follow the steps below

ros2 run micro_ros_setup create_agent_ws.sh

We will now build the agent packages and, when this is done, source the installation:

# Build step
ros2 run micro_ros_setup build_agent.sh

For using micro-ROS commands you need to run the command :

source ~/microros_ws/install/local_setup.bash

everytime when you open a new terminal for avoiding this we can put the source command on bashrc file as shown above.

Setup Arduino IDE

Follow this tutorial for Installing the ESP32 Board in Arduino IDE (IMPORTANT)

Download precompiled micro-ROS library for arduino IDE from here

Download the zip file

After downloading unzip the file and put it in the location /home/$USERNAME/Arduino/libraries/

If libraries folder is not present inside Arduino folder create it and put the file as shown below.

Place the unziped micro-ROS arduino library here

After completing this, check the example folder below

Check for micro_ros_arduino

If you don't see micro_ros_arduino in example, the library is not installed properly.

Open the micro_ros_publisher program on the example shown above. Compile it and upload to ESP32. This program publishes integer values to the topic /micro_ros_arduino_node_publisher.

Running micro-ROS agent in ROS 2 Humble

Make sure to source ros2 path as shown below

source /opt/ros/humble/setup.bash

then run the agent program

ros2 run micro_ros_agent micro_ros_agent serial --dev /dev/ttyACM0

output of the above command is

micro-ros agent is running

then press the reset button(EN) of ESP32

Press the EN button

It will show like below

Open a new terminal without closing the above and run the below command for showing all the available topics

ros2 topic list

it shows

/micro_ros_arduino_node_publisher topic is publised by ESP32

for showing the msg published to the topic /micro_ros_ardunio_node_publisher run the following command

ros2 topic echo /micro_ros_arduino_node_publisher

it will gives the output

Here we can see that data is successfully published from ESP32.

For the graphical visualization run

rqt_graph

it will show

Here we can see /micro_ros_arduino_node publishes to topic /micro_ros_arduino_node_publisher.

micro_ros_publisher_example

#include <micro_ros_arduino.h>

#include <stdio.h>
#include <rcl/rcl.h>
#include <rcl/error_handling.h>
#include <rclc/rclc.h>
#include <rclc/executor.h>

#include <std_msgs/msg/int32.h>

rcl_publisher_t publisher;
std_msgs__msg__Int32 msg;
rclc_executor_t executor;
rclc_support_t support;
rcl_allocator_t allocator;
rcl_node_t node;
rcl_timer_t timer;

#define LED_PIN 13

#define RCCHECK(fn) { rcl_ret_t temp_rc = fn; if((temp_rc != RCL_RET_OK)){error_loop();}}
#define RCSOFTCHECK(fn) { rcl_ret_t temp_rc = fn; if((temp_rc != RCL_RET_OK)){}}


void error_loop(){
  while(1){
    digitalWrite(LED_PIN, !digitalRead(LED_PIN));
    delay(100);
  }
}

void timer_callback(rcl_timer_t * timer, int64_t last_call_time)
{  
  RCLC_UNUSED(last_call_time);
  if (timer != NULL) {
    RCSOFTCHECK(rcl_publish(&publisher, &msg, NULL));
    msg.data++;
  }
}

void setup() {
  set_microros_transports();
  
  pinMode(LED_PIN, OUTPUT);
  digitalWrite(LED_PIN, HIGH);  
  
  delay(2000);

  allocator = rcl_get_default_allocator();

  //create init_options
  RCCHECK(rclc_support_init(&support, 0, NULL, &allocator));

  // create node
  RCCHECK(rclc_node_init_default(&node, "micro_ros_arduino_node", "", &support));

  // create publisher
  RCCHECK(rclc_publisher_init_default(
    &publisher,
    &node,
    ROSIDL_GET_MSG_TYPE_SUPPORT(std_msgs, msg, Int32),
    "micro_ros_arduino_node_publisher"));

  // create timer,
  const unsigned int timer_timeout = 1000;
  RCCHECK(rclc_timer_init_default(
    &timer,
    &support,
    RCL_MS_TO_NS(timer_timeout),
    timer_callback));

  // create executor
  RCCHECK(rclc_executor_init(&executor, &support.context, 1, &allocator));
  RCCHECK(rclc_executor_add_timer(&executor, &timer));

  msg.data = 0;
}

void loop() {
  delay(100);
  RCSOFTCHECK(rclc_executor_spin_some(&executor, RCL_MS_TO_NS(100)));
}

Credits

Amal Shaji

3 projects • 4 followers

I'm undergraduate student fascinated towards technology. Trying to build useful projects.

Nuhman Jaseel

3 projects • 4 followers

Thanks to micro-ROS official documentation .

Micro ros on ESP32 using arduino IDE

Things used in this project

Hardware components

Software apps and online services

Story

System specification

Installation micro-ROS agent

Setup Arduino IDE

Running micro-ROS agent in ROS 2 Humble

Code

micro_ros_publisher_example

Credits

Amal Shaji

Nuhman Jaseel

Comments

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Micro ros on ESP32 using arduino IDE

Micro ros on ESP32 using arduino IDE

Things used in this project

Hardware components

Software apps and online services

Story

System specification

Installation micro-ROS agent

Setup Arduino IDE

Running micro-ROS agent in ROS 2 Humble

Code

micro_ros_publisher_example

Credits

Amal Shaji

Nuhman Jaseel

Comments

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