I am powering a genuine Nano from a 5V 3A regulated power supply going into the nano's 5V and GND pins. I also have a PCA9685 running servos that I'd like to power from the same 5V regulated power supply.
I need to power the PCA through the header pins, rather than the terminal blocks (due to size constraints).
So here's what I'm thinking:
- Nano powered from regulated supply to nano 5V pin and GND
- PCA powered parallel to nano from regulated supply to V+ pin and GND
- PCA logic powered from nano's 3V3 output to VCC
- Is this healthy? I would think this would avoid any issues from powering USB at the same time as the power supply.
- Does this bring up any issues with pull-up resistors with the PCA logic operating at a different voltage than the nano's? From the PCA manual: "This [VCC] is the logic power pin, connect this to the logic level you want to use for the PCA9685 output, should be 3 - 5V max! It's also used for the 10K pullups on SCL/SDA so unless you have your own pullups, have it match the microcontroller's logic level too!"
If I wanted to keep everything at 5V, is it a problem tying the V+ and VCC together on the PCA?
Have mercy, I'm a mechanical engineer