ESP32 WROOM-32 + BNO08x IMU (GY-BNO080) Fails to Return Readings — I²C Setup Help Needed

Hello everyone,

I’m working on a VR project and need help getting sensor data from the BNO08x using an ESP32 Dev Board over I²C.

Hardware I’m Using:

1. BNO08x IMU (GY-BNO080/BNO085 breakout)

   Amazon Link
   9DOF AHRS sensor, supports quaternion output and sensor fusion.

2. ESP32 WROOM-32 Dev Board by OceanLabz

   Amazon Link
   Dual-core WiFi + Bluetooth module, USB-C with CP2102 chip.

Goal:

Read accurate Yaw / Pitch / Roll (orientation) data from the BNO08x via I²C using the Adafruit BNO08x library.

Wiring Connections (I²C Mode)

Libraries Used

• Adafruit BNO08x Library (installed via Library Manager)
• Wire.h (default I²C library)
• Board: ESP32 Dev Module (from Espressif)

Step 1: I²C Scanner Test

To confirm the I²C address, I used the standard scanner:

#include <Wire.h>
#define SDA_PIN 21
#define SCL_PIN 22

void setup() {
  Serial.begin(115200);
  Wire.begin(SDA_PIN, SCL_PIN);
  Serial.println("I2C Scanner Running...");

  for (byte addr = 1; addr < 127; addr++) {
    Wire.beginTransmission(addr);
    if (Wire.endTransmission() == 0) {
      Serial.print("I2C device found at 0x");
      Serial.println(addr, HEX);
    }
  }
}
void loop() {}

Output:

I2C device found at 0x4B

So the sensor is connected properly and acknowledged by the ESP32.

Step 2: Reading Sensor Data (Code Below)

Then, I tried using the Adafruit BNO08x example for rotation vector output (modified for my pins and I²C address):

#include <Wire.h>
#include <Adafruit_BNO08x.h>

#define SDA_PIN 21
#define SCL_PIN 22

Adafruit_BNO08x bno08x;
sh2_SensorValue_t sensorValue;

struct euler_t { float yaw, pitch, roll; } ypr;
sh2_SensorId_t reportType = SH2_ARVR_STABILIZED_RV;
long reportIntervalUs = 5000;

void setReports() {
  if (!bno08x.enableReport(reportType, reportIntervalUs)) {
    Serial.println("❌ Could not enable report");
  }
}

void quaternionToEuler(float qr, float qi, float qj, float qk, euler_t* ypr) {
  float sqr = qr*qr, sqi = qi*qi, sqj = qj*qj, sqk = qk*qk;
  ypr->yaw = atan2(2*(qi*qj + qk*qr), (sqi - sqj - sqk + sqr)) * RAD_TO_DEG;
  ypr->pitch = asin(-2*(qi*qk - qj*qr) / (sqi + sqj + sqk + sqr)) * RAD_TO_DEG;
  ypr->roll = atan2(2*(qj*qk + qi*qr), (-sqi - sqj + sqk + sqr)) * RAD_TO_DEG;
}

void setup() {
  Serial.begin(115200);
  Wire.begin(SDA_PIN, SCL_PIN);
  Wire.setClock(100000);

  Serial.println("BNO08x I2C Test");
  if (!bno08x.begin_I2C(0x4B, &Wire)) {
    Serial.println("❌ BNO08x not found at 0x4B");
    while (1);
  }

  Serial.println("✅ BNO08x Found!");
  setReports();
}

void loop() {
  if (bno08x.wasReset()) {
    setReports();
  }

  if (bno08x.getSensorEvent(&sensorValue)) {
    if (sensorValue.sensorId == SH2_ARVR_STABILIZED_RV) {
      quaternionToEuler(sensorValue.un.arvrStabilizedRV.real,
                        sensorValue.un.arvrStabilizedRV.i,
                        sensorValue.un.arvrStabilizedRV.j,
                        sensorValue.un.arvrStabilizedRV.k,
                        &ypr);

      Serial.print("Yaw: "); Serial.print(ypr.yaw, 2);
      Serial.print("  Pitch: "); Serial.print(ypr.pitch, 2);
      Serial.print("  Roll: "); Serial.println(ypr.roll, 2);
    }
  }
}

Output

Despite successful I²C detection at 0x4B, the output is fails with this error:

❌ BNO08x not found at 0x4B

What I Need Help With

• Is the connection wrong ?
• Is the hardware wrong ?
• Or anything else ?

Related Posts

I found similar issues by other users like:

• Anis – "Sensor not detected"
• Shivpat – QuaternionYawPitchRoll issues

Unfortunately, those threads don’t explain how the issue was eventually resolved.

I’ll be uploading photos of my hardware setup shortly in case it helps spot wiring issues.

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