I am using PCA9685 in a project. 3 are on the same i2c bus and thus I need to change the address of individual ICs. It has 5 selectable address bits as shown in the figure below:
The address will change depending on whether A0…A5 are tied to GND or VCC.
Datasheet says that:
To conserve power, no internal pull-up resistors are incorporated on
the hardware selectable address pins and they must be pulled HIGH or
LOW.
Does it mean I need to use external resistors for pull up or pull down or am I allowed to directly connect the address pins to GND or VCC as per my requirement?
Best Answer
You can do both. What they mean is that, if you connect the pin to either GND or VCC, there will be no current wasted due to some internal pull-up/pull-down.
But whether you connect it directly or through a resistor does not really matter. I suggest you connect them directly for simplicity.