One-Byte Only I²C Slave on chipKIT Boards

[ReiVilo]

On the chipKIT Uno32, uC32, DP32 and WF32, the interrupt is raised for every byte in I²C slave mode. The corresponding MCUs are the PIC32MX320F128, PIC32MX340F512H, PIC32MX250F128B and PIC32MX695F512L. I don't know for other boards / MCUs as I've only tested with those I own.

This bug/feature was confirmed at chipKIT forum and there's a related issue at the GitHub repository

• I2C wire library & repeated start (Sr) http://chipkit.net/forum/viewtopic.php?f=7&t=1469
• Wire onReceive(handler) issue http://chipkit.net/forum/viewtopic.php?f=7&t=1076
• I2C Slave Receive Problems http://chipkit.net/forum/viewtopic.php?f=7&t=548
• TWI I2C Wire Library Limited to 1 Byte in Slave Mode https://github.com/chipKIT32/chipKIT32-MAX/issues/310#issuecomment-100921796 

Unfortunately, the question hasn't received any official answer yet. The suggested work-around isn't reliable as it requires to be set for every I²C master.

Is it a bug?

[TommyK]

Hi ReiVilo,

Have you tried using Digilent's DTWI library? You can find an example in MPIDE under Wire>I2CSlaveSimEEPROM. I know the native TWI library is a bit buggy, and Keith took a long time making this library as efficient as possible.

-Tommy