I'm trying to have 2 slaves and 1 master arduino setup for I2C. Now a single slave single master configuration works with both slaves. but when i connect all of them together it doesn't work. All powered from USB of the same laptop, the common lines pulled up with 4.7k, Grounds shorted as well. The communication between the master and the slave stops as soon as i plug in the 2nd slave. What could be going wrong?
Does it matter which slave (4 or 5) is connected first, i.e. can either slave be introduced second?
Have you wired an LED (or some indicator) to show when each slave thinks it's being talked to? If not, would you add the LED to each slave, and modify the code? Then confirm that they do NOT both think they are being talked to at the same time?
Just had a thought ... there could be too much pull up with three arduinos in the circuit especially if you have an external pull up resistor as well.
If you have an external pull up resistor try changing that to 10K.