This is the MCU: http://www.microchip.com/wwwproducts/en/ATtiny88 - it advertises a hardware I2C interface, but I am struggling with it. It is mounted on my own board (which worked fine if I dropped an ATMega instead).
edited - prev screencapture were from an ungrounded logic analyzer
First tried the Femtocow ATTiny - it has complained about no Wire library at the
#include Wire.h line. So i went into
C:\Program Files\Arduino\hardware\arduino\avr\libraries, grabbed the Wire folder and copied it into
C:\Program Files\Arduino\libraries. Compiled fine, loaded the binary with avrdude, got a few first TWI communication fine, then it started trashing.
Second attempt was with the cores from Drazzy ATTinycore which came with its own Wire library. Compiled fine, loaded the binary and got the same behaviour.
This is how the messed up I2C line looks in both cases. Starts fine, then appears to go wonky, after a few of these wonky bursts the lines go silent. Also, in spite of having changed the frequency to both 100 and 400 kHz i have this weird 1.953 kHz clock...
#define F_TWI 400000L //#define F_TWI 100000L .... Wire.begin(); // Initiate the Wire library Wire.setClock(F_TWI);
I am using Arduino 1.8.2. Anything gives ?