BNO08x::begin() hangs when trying to return _init()

[Donato-M]

Subject of the issue

Running the example 1 code does not work. Upon testing I have found the issue to be in the begin() method. It runs up until it reaches the final return point where it is supposed to return _init().

Your workbench

• What development board or microcontroller are you using?
• ESP32-WROOM-32E
• What version of hardware or breakout board are you using?
• How is the breakout board to your microcontroller?
• The microcontroller is connected to my laptop via a micro-USB cable and the ESP32 Tester V1.1
• How is everything being powered?
  *Power is supplied via the USB cable
• Are there any additional details that may help us help you?
• The BNO is soldered to a custom made PCB with all the necessary capacitors and resistors as specified in the BNO's datasheet for I2C communication.
• The BNO085 is connected to an I2C bus along with a number of other device. Communicating with these devices doesn't pose any problems

Steps to reproduce

Tell us how to reproduce this issue. Please post stripped down example code demonstrating your issue.
I attempted to get the BNO working using example 1. I changed the pin numbers and the I2C address to match the connections on the PCB the BNO is on.

#define BNO08X_INT 27
#define BNO08X_RST 12
#define BNO08X_ADDR 0x4A // Alternate address if ADR jumper is closed

Expected behavior

The Rotation vector example should execute

Actual behavior

The program halts at the return _init() line of begin().

/*
  Using the BNO08x IMU

  This example shows how to output the i/j/k/real parts of the rotation vector.
  https://en.wikipedia.org/wiki/Quaternions_and_spatial_rotation

  By: Nathan Seidle
  SparkFun Electronics
  Date: December 21st, 2017
  SparkFun code, firmware, and software is released under the MIT License.
	Please see LICENSE.md for further details.

  Originally written by Nathan Seidle @ SparkFun Electronics, December 28th, 2017

  Adjusted by Pete Lewis @ SparkFun Electronics, June 2023 to incorporate the
  CEVA Sensor Hub Driver, found here:
  https://github.com/ceva-dsp/sh2

  Also, utilizing code from the Adafruit BNO08x Arduino Library by Bryan Siepert
  for Adafruit Industries. Found here:
  https://github.com/adafruit/Adafruit_BNO08x

  Also, utilizing I2C and SPI read/write functions and code from the Adafruit
  BusIO library found here:
  https://github.com/adafruit/Adafruit_BusIO

  Hardware Connections:
  IoT RedBoard --> BNO08x
  QWIIC --> QWIIC
  A4  --> INT
  A5  --> RST

  BNO08x "mode" jumpers set for I2C (default):
  PSO: OPEN
  PS1: OPEN

  Serial.print it out at 115200 baud to serial monitor.

  Feel like supporting our work? Buy a board from SparkFun!
  https://www.sparkfun.com/products/22857
*/

#include <Wire.h>

#include "SparkFun_BNO08x_Arduino_Library.h"  // CTRL+Click here to get the library: http://librarymanager/All#SparkFun_BNO08x
BNO08x myIMU;

// For the most reliable interaction with the SHTP bus, we need
// to use hardware reset control, and to monitor the H_INT pin.
// The H_INT pin will go low when its okay to talk on the SHTP bus.
// Note, these can be other GPIO if you like.
// Define as -1 to disable these features.
#define BNO08X_INT  27
//#define BNO08X_INT  -1
#define BNO08X_RST  12
//#define BNO08X_RST  -1

//#define BNO08X_ADDR 0x4B  // SparkFun BNO08x Breakout (Qwiic) defaults to 0x4B
#define BNO08X_ADDR 0x4A // Alternate address if ADR jumper is closed

void setup() {
  Serial.begin(115200);
  
  while(!Serial) delay(10); // Wait for Serial to become available.
  // Necessary for boards with native USB (like the SAMD51 Thing+).
  // For a final version of a project that does not need serial debug (or a USB cable plugged in),
  // Comment out this while loop, or it will prevent the remaining code from running.
  
  Serial.println();
  Serial.println("BNO08x Read Example");

  Wire.begin(21, 22, 350000);

  //if (myIMU.begin() == false) {  // Setup without INT/RST control (Not Recommended)
  if (myIMU.begin(BNO08X_ADDR, Wire, BNO08X_INT, BNO08X_RST) == false) {
    Serial.println("BNO08x not detected at default I2C address. Check your jumpers and the hookup guide. Freezing...");
    while (1)
      ;
  }
  Serial.println("BNO08x found!");

  // Wire.setClock(400000); //Increase I2C data rate to 400kHz

  setReports();

  Serial.println("Reading events");
  delay(100);
}

// Here is where you define the sensor outputs you want to receive
void setReports(void) {
  Serial.println("Setting desired reports");
  if (myIMU.enableRotationVector() == true) {
    Serial.println(F("Rotation vector enabled"));
    Serial.println(F("Output in form i, j, k, real, accuracy"));
  } else {
    Serial.println("Could not enable rotation vector");
  }
  delay(100);
}

void loop() {
  delay(10);

  if (myIMU.wasReset()) {
    Serial.print("sensor was reset ");
    setReports();
  }

  // Has a new event come in on the Sensor Hub Bus?
  if (myIMU.getSensorEvent() == true) {

    // is it the correct sensor data we want?
    if (myIMU.getSensorEventID() == SENSOR_REPORTID_ROTATION_VECTOR) {

      float quatI = myIMU.getQuatI();
      float quatJ = myIMU.getQuatJ();
      float quatK = myIMU.getQuatK();
      float quatReal = myIMU.getQuatReal();
      float quatRadianAccuracy = myIMU.getQuatRadianAccuracy();

      Serial.print(quatI, 2);
      Serial.print(F(","));
      Serial.print(quatJ, 2);
      Serial.print(F(","));
      Serial.print(quatK, 2);
      Serial.print(F(","));
      Serial.print(quatReal, 2);
      Serial.print(F(","));
      Serial.print(quatRadianAccuracy, 2);

      Serial.println();
    }
  }
}
```
![image](https://github.com/sparkfun/SparkFun_BNO08x_Arduino_Library/assets/110125544/36b6dae8-abe1-4bd7-890b-c66bbf7cf0b3)

[Donato-M]

Upon poking around in the library files I've found the issue to be in the sh2_getProdIds method, located in the sh2.c file. I'll be honest and say I have no idea what this method is doing and can't even figure out where to begin trying to understand why I'm encountering an error