Diagnosing and handling lock ups

[toptensoftware]

Hi Richard,

Firstly, thank you for this library - I've been enjoying using it so far.

I'm fairly new to I2C so I'm hoping you can give me a couple of pointers on diagnosing some lock up issues I'm having. This is the setup:

• Teensy 4.0, using pins 18/19 for I2c as master
• Latest version of lib from github
• Slave is a raspberry pi running bare metal (circle)
• 2.2K pull up resistors to 3.3V (at the teensy end)
• About 200mm between teensy and pi
• Environment is not particularly noisy. Most noise around the i2c connection would be the pi is also driving a DPI RGB Parallel LCD interface - not sure how impactful that might be
• Sending 1x 20-30 byte packet over i2c every 500ms

Result:

• Getting occasional dropped packet (I need to find a way check, but suspect a checksum error on the packet)
• Runs well for say 10 mins, but then gets stuck with Master.finished() always returning false

Main questions:

• Can the device/library recover from an i2c lockup?
• What's reasons would cause Master.finished() to get stuck like this?
• Is there anything I can do as a client of the library to recover from a lockup?

If you've got any other suggestions on where to start debugging that would also much appreciated.

Brad