How to send battary voltage in SITL using JSON interface?

ArduPlane Plane Simulation
1

Hi,
I am using JSON interface (-> ardupilot/libraries/SITL/examples/JSON/readme.md at master · ArduPilot/ardupilot · GitHub ) for my physical backend in a SITL simulation.

Now I like to change the battary value as well over JSON, so I thought I have to add something like a “battary”-node with a voltage value.

Is this possible and if so how to setup this? (Sorry, I didn’t find a more detailed information about the JSON interface)
In the case this is not the right approach, how can I achive this?

Many thanks for your help

2

You may start from neglecting the following values in SITL/SIM_Aircraft.cpp

    fdm.battery_voltage = battery_voltage;
    fdm.battery_current = battery_current;

after that voltage output should be considered in SIM_JSON.cpp, in the following function:

void JSON::recv_fdm(const struct sitl_input &input)

So by tracking the fdm.battery_voltage = battery_voltage; in sitl to replace its value with the values that received from JSON connection will do what you want

3

Thank you for your response.

I took a look at the code and I understand (or misunderstand) that I have to change the code and build it on my own to achive the goal setting battary values via JSON.

Is that correct?

Thx

4

hello,

Yes, we didn’t implement battery stats into JSON backend, so you will have to do it. Maybe an opportunity for a first contribution ? :grinning_face:

5

Yes, that’s correct. All sections related to these variables should be reviewed and updated accordingly.

6

:smiley: Yes of course! I will do my very best.
Thank you for your reply

7

Thank you very much for your answer. I still need to warm up to the ArduPilot coding world.
I’m sure I’ll have more questions :smiley: