How to Use Micro ROS Control Board (ESP32): Examples, Pinouts, and Specs

The Micro ROS Control Board (ESP32), manufactured by Yahboom, is a compact and versatile microcontroller board based on the ESP32 chip. It is specifically designed for robotics applications and supports Micro ROS, a lightweight version of the Robot Operating System (ROS) tailored for microcontrollers. This board enables efficient communication and control in robotic systems, making it ideal for projects requiring real-time performance and wireless connectivity.

• Robotics control systems
• IoT-enabled robotic devices
• Real-time sensor data acquisition and processing
• Wireless communication in robotic networks
• Integration with ROS-based systems for advanced robotics applications

1. Powering the Board:

   • Connect the board to a 5V power source via the USB port or the VIN pin.
   • Ensure the power supply provides sufficient current (at least 500 mA).

2. Connecting Peripherals:

   • Use the GPIO pins for connecting sensors, actuators, or other peripherals.
   • For I2C devices, connect to the SDA and SCL pins.
   • For SPI devices, use the MOSI, MISO, and SCK pins.

3. Programming the Board:

   • Install the Arduino IDE or PlatformIO for programming.
   • Add the ESP32 board package to your IDE.
   • Install the Micro ROS library for ROS integration.

4. Micro ROS Setup:

   • Configure the Micro ROS agent on your ROS-enabled computer.
   • Use the Micro ROS library to write firmware for the board, enabling communication with the ROS ecosystem.

• Voltage Levels: Ensure all connected peripherals operate at 3.3V logic levels to avoid damaging the board.
• Wi-Fi Interference: Place the board away from sources of electromagnetic interference to maintain stable wireless communication.
• Firmware Updates: Regularly update the ESP32 firmware and Micro ROS library for optimal performance and security.
• Heat Management: Avoid prolonged operation at high loads to prevent overheating.

Below is an example of how to set up the Micro ROS Control Board (ESP32) to publish sensor data to a ROS topic:

#include <micro_ros_arduino.h>
#include <WiFi.h>
#include <std_msgs/String.h>

// Wi-Fi credentials
const char* ssid = "Your_SSID";
const char* password = "Your_PASSWORD";

// ROS node handle
rcl_node_t node;
rcl_publisher_t publisher;
std_msgs__msg__String msg;

// Timer for publishing data
unsigned long last_publish_time = 0;
const unsigned long publish_interval = 1000; // 1 second

void setup() {
  // Initialize serial communication for debugging
  Serial.begin(115200);
  delay(1000);

  // Connect to Wi-Fi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWi-Fi connected!");

  // Initialize Micro ROS
  set_microros_wifi_transports(ssid, password, "192.168.1.100", 8888);

  // Create ROS node and publisher
  node = rcl_get_zero_initialized_node();
  rcl_node_init_default(&node, "esp32_node", "", &rcl_get_default_allocator());

  publisher = rcl_get_zero_initialized_publisher();
  rcl_publisher_init_default(
    &publisher, &node, ROSIDL_GET_MSG_TYPE_SUPPORT(std_msgs, msg, String),
    "sensor_data"
  );

  // Prepare message
  msg.data.data = (char*)malloc(50);
  msg.data.size = 0;
  msg.data.capacity = 50;
}

void loop() {
  // Publish data at regular intervals
  if (millis() - last_publish_time >= publish_interval) {
    last_publish_time = millis();

    // Update message content
    snprintf(msg.data.data, msg.data.capacity, "Hello from ESP32 at %lu ms", millis());
    msg.data.size = strlen(msg.data.data);

    // Publish message
    rcl_publish(&publisher, &msg, NULL);
    Serial.println("Message published!");
  }

  // Handle Micro ROS tasks
  rclc_executor_spin_some(NULL, RCL_MS_TO_NS(100));
}

1. Wi-Fi Connection Fails:

   • Double-check the SSID and password.
   • Ensure the router is within range and not overloaded with devices.

2. Micro ROS Agent Not Found:

   • Verify the IP address and port of the Micro ROS agent.
   • Ensure the agent is running on the ROS-enabled computer.

3. Board Not Detected by IDE:

   • Install the correct USB driver for the ESP32.
   • Check the USB cable and port for proper connection.

4. Overheating:

   • Reduce the workload or add a heatsink to the ESP32 chip.

• Can I use this board without ROS?
  Yes, the board can be used as a standard ESP32 microcontroller for non-ROS applications.

• What is the maximum range of Wi-Fi?
  The range depends on the environment but typically extends up to 30 meters indoors.

• Does the board support OTA updates?
  Yes, the ESP32 supports Over-The-Air (OTA) firmware updates.

• Can I use this board with a LiPo battery?
  Yes, but ensure the battery voltage is regulated to 5V before connecting to the VIN pin.