I2C read or write during an interrupt

[jdelphi]

How can I use a I2C Read or write during a timer interrupt on a dsPic ???

[wireless]

Yes you can use I2C in an interrupt routine but be careful of reentrancy.

For example, if you were in an I2C routine in your main() program and an interrupt occured, also calling the same I2C routine, you would have problems.

It is likely that during compile you will get a warning message saying something like "Interrupts disable in i2c_receive routine to avoid re-entrancy".

Good luck

Regards
Terry

[Ttelmah]

I'd actually suggest, that if wanting to use the I2C hardware in an interrupt, one considers just talking directly to the buffer register, rather than using the CCS functions. It is a one line #byte operation to set this up, then you can just write a byte to the I2C buffer, and leave the hardware to get on with sending it. On the next interrupt, check the I2C status (standard fucntions for this), and send another byte if wanted etc..
This way you don't 'wait' inside the interrupt for the transfer, and let the hardware get on and do the actual work for you, while the code is doing other things.

Best Wishes

[bkamen]