PixRacer Power Module


I’ve wanted to add current and voltage sense capability to my PixRacer, but I’m confused as to what voltage the sense pins expect. Most of the APM modules I’ve found output 0-5v ADC. However, the Pixracer board specs (https://pixhawk.org/modules/pixracer) list it’s current and sense pins as limited to 3.3v.

What power module should I use for the racer that will output its ADC in the correct 0-3.3v range? Is there a way to change the ADC output of power modules without using a voltage divider circuit? Like can I reflash the firmware or something?

Currently, I’m using this (https://www.amazon.com/FPVDrone-Module-Current-Pixhawk-Controller/dp/B06XFW1X3K) but without the current or voltage sense pins connected.

Thank you for any tips/guidance provided. This is my first drone I’ve built and would hate to accidentally fry the flight controller.

This is a good one

Thank you CarlOlsson, that is quite a nice one. Its a bit outside my budget though. :weary: Have you used it in the past? Since if it really does provide much better battery estimates then it could be worth it.

I have one additional question about the ADC output of the apm modules in general. Do they just output a dc value proportional to measured voltage and current? As in, would the module I already have still work as long as I don’t draw more than like 40 amps through it and don’t hook it up to a 6s battery?

Thank you!

Battery estimation is not only related to ADC accuracy, but also the battery gas gauge driver runs inside flight controller as well.

Ideally a dedicated gas gauge IC should be presented to do the thing, however as per current software implementation you can not expect too much about battery estimation accuracy anyway.