Hello Lubin,

I'm using the Sparkfun's UDB4 board.

I've tried to make his I2c to work and I bump into something strange.



[ Before i'll continue, just for the protocol, I have already tested the I2C block on GlounPilot's board (dsPIC33fj256jMC710) and it worked fine ] .



So, here is the problem:

This board have 2 port of I2C. One suppose to be used by the EEPROM and the other is free to connect. Both ports are connected to PULL-UP resistors on the board.

I've made a simple model which use I2C_2 and sends a constant number to a constant address every 0.1 sec. here is the model:


After that, I have touched with a scope on I2C_1 (mark as (1) on the picture) and I2C_2 and i found out that they both show the same signal (its a bad signal, but i'll keep this problem for the next topic).



After that i changed th model to I2C_1 and no signal appear on both ports (i have tried to touch directly on the PULL-UP).



Here is a picture of the board, i marked the I2C_1 and I2C_2 and the PULL-UP resistors:


Lubin, can you please test it on your board?



Thanks,

Alpert

OK. Problem solved after clicking on "Erase flash device" in MPLAB.

Mybe the problem has occur because the MPLAB's programer set to "Allow PICkit 3 to select memories and ranges" and from some reason it didn't update all the registers (Lubin, is it a possible explanation?)



Now there is another problem with the I2C, but i will start a new topic for it.