Arduino  I2C/TWI <----> Attiny2313

Dear reader,

For a project we need to read out the serial data from ~5 RFID readers. Each RFID reader will get it's own casing with some nice lights in it. We've tried to use attiny2313 as a I2C slave (or as it''s called TWI) and one Arduino as the master. When the Arduino sends data to a slave, the data is received correctly. I'm using USE_TWI_Slave.h/c filles I got from Atmel.

Now we want the attiny2313 slaves to send data back to the master and this is where the problems start. The master and slave seem to "hang" or wait for each other. I'm not totally sure what's happening but as I read it can be due to speed/timing. I read the slave can hold the clock line low to tell the master to delay the transfer. This would make some sense, but I've no scope so I cannot check this.

I was hoping other people maybe had a same situation and see what's the problem.

Kind regards Roxlu

Hi Richard,

I'm using an Arduino ánd a couple of attiny2313 ics.

Kind regards.