Closed
Description
Board
ESP32C6, ESP32C3
Device Description
XIAO ESP32C6, ESP32C3 Super Mini
Hardware Configuration
I2C not working when IMU connected to SDA and SCL pins (22,23 for XIAO and 8,9 for Super Mini)
Version
v3.2.0
IDE Name
Arduino IDE
Operating System
MacOS 13.3.1, Windows 11
Flash frequency
80MHz
PSRAM enabled
yes
Upload speed
921600
Description
With version 3.2.0, I2C stopped working on my ESP32C6 and ESP32C3
See full explanation here: https://www.reddit.com/r/esp32/comments/1kj5shf/esp32_and_bmi160_icm20948_connection_i2c_issues/
E (1351) i2c.master: I2C transaction unexpected nack detected
E (1351) i2c.master: s_i2c_synchronous_transaction(924): I2C transaction failed
E (1352) i2c.master: i2c_master_transmit_receive(1220): I2C transaction failed
Reverting to v3.1.3 solved the issue.
Sketch
#include <Wire.h>
// I2C Configuration for ESP32
#define BMI160_I2C_ADDRESS 0x68 // I2C address for BMI160 (with SAO pin → GND), connect to 3V3 for 0x69
#define BMI160_SDA_PIN 22 // I2C D4(GPIO22) → SDA Pin for XIAO ESP32C6
#define BMI160_SCL_PIN 23 // I2C D5(GPIO23) → SCL Pin for XIAO ESP32C6
#define ACCEL_SENSITIVITY 16384.0 // Sensitivity for ±2g in LSB/g (adjust based on your configuration)
void setup() {
Serial.begin(115200); // Initialize Serial communication
Wire.begin(BMI160_SDA_PIN, BMI160_SCL_PIN); // Initialize I2C communication
// Initialize BMI160 accelerometer
Wire.beginTransmission(BMI160_I2C_ADDRESS);
Wire.write(0x7E); // Command register
Wire.write(0x11); // Set accelerometer to normal mode
Wire.endTransmission();
delay(100);
// Perform accelerometer auto-calibration
autoCalibrateAccelerometer();
Serial.println("BMI160 Initialized and Calibrated");
}
void loop() {
int16_t ax, ay, az;
// Read accelerometer data
Wire.beginTransmission(BMI160_I2C_ADDRESS);
Wire.write(0x12); // Start register for accelerometer data
Wire.endTransmission(false);
Wire.requestFrom(BMI160_I2C_ADDRESS, 6);
if (Wire.available() == 6) {
ax = (Wire.read() | (Wire.read() << 8));
ay = (Wire.read() | (Wire.read() << 8));
az = (Wire.read() | (Wire.read() << 8));
}
// Convert raw accelerometer values to m/s^2
float ax_mps2 = ax /ACCEL_SENSITIVITY *9.81;
float ay_mps2 = ay /ACCEL_SENSITIVITY *9.81;
float az_mps2 = az /ACCEL_SENSITIVITY *9.81;
// Print accelerometer values in m/s^2
Serial.print("Acceleration (m/s^2): ");
Serial.print(ax_mps2-0.1, 2);
Serial.print(", ");
Serial.print(ay_mps2+0.7, 2);
Serial.print(", ");
Serial.print(az_mps2, 2);
Serial.print(". \t");
// Convert raw accelerometer values to g
float ax_g = ax / ACCEL_SENSITIVITY;
float ay_g = ay / ACCEL_SENSITIVITY;
float az_g = az / ACCEL_SENSITIVITY;
// Calculate tilt angles (pitch and roll) in degrees
float pitch = atan2(ay_g, sqrt(ax_g * ax_g + az_g * az_g)) * 180.0 / PI;
float roll = atan2(-ax_g, az_g) * 180.0 / PI;
// Print tilt angles
Serial.print("Pitch: ");
Serial.print(pitch+4.5, 2);
Serial.print("°, Roll: ");
Serial.print(roll+178.6, 2);
Serial.println("°");
delay(500);
}
void autoCalibrateAccelerometer() {
// Configure accelerometer for auto-calibration
Wire.beginTransmission(BMI160_I2C_ADDRESS);
Wire.write(0x7E); // Command register
Wire.write(0x37); // Start accelerometer offset calibration
Wire.endTransmission();
delay(100);
// Wait for calibration to complete
delay(1000);
Serial.println("Accelerometer Auto-Calibration Complete");
}Debug Message
E (1351) i2c.master: I2C transaction unexpected nack detected
E (1351) i2c.master: s_i2c_synchronous_transaction(924): I2C transaction failed
E (1352) i2c.master: i2c_master_transmit_receive(1220): I2C transaction failed
Other Steps to Reproduce
No response
I have checked existing issues, online documentation and the Troubleshooting Guide
- I confirm I have checked existing issues, online documentation and Troubleshooting guide.