UART battery monitor

ArduRover ArduBoat
1

Good morning,

I am currently using a LiFePo battery with my vehicle due to safety issues with LiPO. The thing is that these batteries have a pretty constant voltage so it is not easy to monitor the capacity of the battery. The thing is that I have connected a sensor that has an UART output. I’ve been trying to send the information to the PixHawk but apparently I can’t. I’ve also tried using lua scripts but I cannot pass the battery voltage to the FC.
Any ideas on how to make the UART battery monitor work?

Thank you,

2

Hello @Magix, I may not get you at this point. Why constant voltage make it difficult to monitor tha battery capacity - here I assume that “capacity” means mAh

There are several ways to “feed” the Ardupilot battery information

  1. Using Mavlink: You need to have intermediate hardware (such as microcontrollers, embedded PC) to read the battery and send the BATTERY_STATUS messages to Ardupilot
    Some useful links about how it goes:
    Simple way MAVLink and Arduino: step by step
    Battery status message Battery Protocol · MAVLink Developer Guide

  2. Using UAVCAN: https://uavcan.org/specification/UAVCAN_Specification_v1.0-beta.pdf#batteryinfo this is more difficult to implement compared to the 1.

  3. Why just simply use the Analog voltage/current measuring feature from Ardupilot: Power Monitor/Module Configuration in Mission Planner — Copter documentation

Hope this helps.
Vu.

3

Hi Vu thank you for your quick reply,

The thing is that I am trying to have sort of a “smart” battery, so that the same battery had the information of its charge. I was hoping I could avoid using an arduino by purchaising a comercial sensor that has a TTL output, however it seems like I will need to introduce a microcontroller.

Thank you for your help!

4

I have requested support for common UART BMS boards, but you probably won’t see support until the summer

5

Oh thanks, GeoMuir, good to know. I’ll keep an eye on this feature. For the moment it looks like I’ll have to use an Arduino in the middle.