Dataflash logging

Archive
1

I’m running 2.4.3 on APM and trying to get Dataflash logging to work.

Through the standard interface, the only options are “Default” and “Default+IMU”. What I need is RC inputs and servo outputs as well. According to the Copter page, you can set more options through the terminal.

When we connect via terminal, all we get is pages of gibberish. Any ideas on what I’m doing wrong?

If we connect, will we be able to use the “advanced” logging stuff similar to copter, or are we locked into only IMU for Rover?

2

@mroberts,
I have sent a request to our programmer, Tridge, to see if he can help you out with this dataflash issue. He has been pretty busy lately with the Pixhawk effort so I do not know how long it will take him to respond.
Regards,
TCIII Developer

3

I was trying to connect via radio. Apparently I need to use USB instead.

4

@mroberts,
Yes, you can only download the flashdata logs using the CLI in the Terminal Tab when communicating with the APM using the USB.
Regards,
TCIII Developer

5

I’ve done some more digging. Rover doesn’t appear to support the following logging options:
MOTOR
ERR
INAV

Are these named differently in Rover vs. Plane and Copter? I haven’t dived into the code yet, but if they’re not in Rover I’m wondering if it’s feasible for me to copy the relevant code across from Plane or Copter. Was there a reason they weren’t implemented, or was it just a matter of finite time and priorities?

I also can’t find any option from plane or copter that purports to record the RC command inputs - is it under a different name?

6

@mroberts,
To the best of my knowledge, RC inputs and outputs appear in the tlogs.
Regards,
TCIII Developer

7

True, but the data rate isn’t fast enough. It may be a separate problem, but I can’t get any changes to the telemetry rates in APM Options to actual persist - if I navigate away from the page and back again they’ve reverted to the (slow) defaults.

There are also caveats in the docs that the radio telemetry has limited bandwidth / data rates, so you will be naturally capped on your capture rates.

The full 50Hz recording would be very handy for troubleshooting / tweaking the steering gains. I’m about to setup a PX4 next week, so the increased processor speed may solve some of the problems with steering response.

8

@mroberts,
If you are using the 3DR telemetry radios, there has been a recent code upgrade that has reduce the transmission latency. You can upgrade the telemetry radio firmware using the MP.
Regards,
TCIII Developer