Example Code for Arduino-Reading Data via UART and Interrupts

Hardware Preparation

• DFR1222 FireBeetle 2 ESP32-C5 ×1
• SEN0694 Gravity: 9 DOF IMU Sensor ×1

Software Preparation

• Download and install Arduino IDE: Download Arduino IDE
• Download and install the DFRobot_Multi_DOF_IMU library: Download DFRobot_Multi_DOF_IMU Library
• Download and install the DFRobot_RTU library: Download DFRobot_RTU Library
• Library Installation Guide: View Installation Guide

Wiring Diagram

Connect the 9 DOF IMU sensor to the ESP32-C5 as shown in the diagram. The main connections are as follows:

• Sensor pin “+” → ESP32-C5 3.3V
• Sensor pin “-” → ESP32-C5 GND
• Sensor pin “INT1” → ESP32-C5 GPIO27
• Sensor pin “INT3” → ESP32-C5 GPIO28
• Sensor UART pin “RX” → ESP32-C5 D3 (GPIO26)
• Sensor UART pin “TX” → ESP32-C5 D2 (GPIO8)
• Sensor DIP switch configuration: Set the communication mode to UART, and set the address to 0x4A(A0=0,A1=0)

Sample Code

#include "DFRobot_Multi_DOF_IMU.h"

// Only keep UART communication mode
#define IMU_COMM_UART
const uint8_t ADDR = 0x4A;

// ESP32-C5 UART1 mapping: RX = GPIO8(D2), TX = GPIO26(D3)
DFRobot_Multi_DOF_IMU_UART imu(DFRobot_Multi_DOF_IMU::eSensorModel9DOF, &Serial1, 9600, ADDR, /*rx=*/8, /*tx=*/26);

volatile bool int1DataReady = false;
volatile bool int3DataReady = false;

// Data ready interrupt service routine for INT1
void IRAM_ATTR int1ISR() {
  int1DataReady = true;
}

// Data ready interrupt service routine for INT3
void IRAM_ATTR int3ISR() {
  int3DataReady = true;
}

void setup() {
  // Initialize serial monitor (baud rate: 115200)
  Serial.begin(115200);
  while (!Serial) delay(10);

  // Initialize sensor
  while (!imu.begin()) {
    delay(1000);
  }

  // Set sensor to normal mode
  imu.setSensorMode(DFRobot_Multi_DOF_IMU::eNormalMode);
  delay(100);

  // Set accelerometer range to ±2G
  Serial.print("Set accel range ±2G... ");
  while (!imu.setAccelRange(DFRobot_Multi_DOF_IMU::eAccelRange2G)) {
    delay(1000);
  }
  Serial.println("OK");

  // Set gyroscope range to ±250dps
  Serial.print("Set gyro range ±250dps... ");
  while (!imu.setGyroRange(DFRobot_Multi_DOF_IMU::eGyroRange250DPS)) {
    delay(1000);
  }
  Serial.println("OK");

  // Configure INT1 data ready interrupt
  Serial.print("Config INT1 (data ready)... ");
  while (!imu.setInt(DFRobot_Multi_DOF_IMU::eImuIntPin1, DFRobot_Multi_DOF_IMU::eInt1_2DataReady)) {
    delay(1000);
  }
  Serial.println("OK");

  // Configure INT3 data ready interrupt
  Serial.print("Config INT3 (data ready)... ");
  while (!imu.setInt(DFRobot_Multi_DOF_IMU::eImuIntPin3, DFRobot_Multi_DOF_IMU::eInt3DataReady)) {
    delay(1000);
  }
  Serial.println("OK");

  // Attach interrupts for INT1 (GPIO27) and INT3 (GPIO28), rising edge trigger
  attachInterrupt(digitalPinToInterrupt(27), int1ISR, RISING);
  attachInterrupt(digitalPinToInterrupt(28), int3ISR, RISING);
  Serial.println("Interrupts attached (rising edge)");

  // Configuration complete prompt
  Serial.println("\nConfiguration complete. Reading data...");
}

void loop() {
  if (int1DataReady || int3DataReady) {
    if (int1DataReady && int3DataReady) {
      int1DataReady = false;
      int3DataReady = false;

      DFRobot_Multi_DOF_IMU::sSensorData_t accel, gyro, mag;
      if (imu.get9dofData(&accel, &gyro, &mag)) {
        // Print format strictly matches the image
        Serial.print("\nACCEL(g): ");
        Serial.print(accel.x, 3); Serial.print(", ");
        Serial.print(accel.y, 3); Serial.print(", ");
        Serial.println(accel.z, 3);

        Serial.print("GYRO(dps): ");
        Serial.print(gyro.x, 2); Serial.print(", ");
        Serial.print(gyro.y, 2); Serial.print(", ");
        Serial.println(gyro.z, 2);

        Serial.print("MAG(uT): ");
        Serial.print(mag.x, 2); Serial.print(", ");
        Serial.print(mag.y, 2); Serial.print(", ");
        Serial.println(mag.z, 2);
      }
    } else {
      // Clear incomplete interrupt flags to avoid deadlock
      if (int1DataReady) int1DataReady = false;
      if (int3DataReady) int3DataReady = false;
    }
  }
  delay(200);
}

Result