Wrong example for ESP8266?

[Eirenliel]

Subject of the issue

Example code recommends setting clock stretch limit for ESP to 4000, despite default clock stretch being 150000. 4000 is not enough for BNO085, it can stretch clock further and it can cause the ESP to skip a bit, misshandle communication with the sensor, and cause it to crash. I recommend not setting stretch limit or setting default value of 150000.

I am curious on how this value ended up in the example, was the default setting not part of i2c driver before?

Your workbench

• What development board or microcontroller are you using?
  • NodeMCU 3 or custom board based on ESP-12F
• What version of hardware or breakout board are you using?
  • Breakout boards from amazon
• How is the breakout board to your microcontroller?
  • SCL, SDA and INT pints to GPIO
• How is everything being powered?
  • Doesn't matter, any power produces the same result

Steps to reproduce

Run any code long enough with low stretch time and it will crash the BNO.

Expected behavior

BNO should not restart itself.

Actual behavior

BNO restarts after random period of time with reset reason 2 (internal reset).