Copter crash from HERE3 Malfunction?

Hello ,

i was doing a test flight for battery failsafe which when it kicked in my copter lost control and got swayed by the wind into a tree .

It seems compass and GPS went flat so am thinking it was some error with the HERE3 unit .

Thank you for your time,

Have you double checked if you had some kind of Wiring Failure in your Here3 module? I have never saw the CAN errors that appear in your log, it seems like it lost CAN connection and then tried several times to restablish communication with several different rates.

Personaly, I think it is always good to have GPS and Compass redundancy.

Hello @BrunoB ,

Thank you for your reply !

Where do you see that it tried to reestablish connection with different rates ?

Yes i checked if the connector was clicked properly in the CAN1 . i dont have any custom wiring the original HERE3 cable directly to CAN1 (in a cube orange).

The POWER.Flags go from 33 to 41 (1+32+8) 8 meaning overcurrent . i had around 80 flights with no issue . since gps compass went flat my possible scenarios are:

  • short circuit on the here3
  • can bus issue in cube
  • actual current too much (i have 2 Terrabee Evo in a i2c strip)

i was hopping a moderator could tell me a way i can test the here3 unit or the CAN bus to get those out of the equation .


Check out the Messages that the Cube were sending during your log in the

You can check these hypothesis using a multimeter and measuring the resistance between ground and 5V.

Indeed, it is always a good practice to power it externaly.

Yep , but which parameter writes those messages ?

Will try testing that .

Can i put a 5v plug on the I2C strip ? would that power the whole strip ?

Thank you for you reply!

These messages are written by various drivers inside ardupilot and are not necessarily related to params. Open a log in the tool I sent you the link and plot any data and look for the messages button, it will open a new window inside it with some messages and you can see them appearing as you pass the mouse on the graph.

I would left the I2C strip away from the power source lines in order to avoid any kind of power noise on the data lines. It’s not a good practice at all to mix power and data wirings.

thats very neat !!! thanks for sharing !,

i think those msgs are “standard” when the here3 starts .

is there any self diagnose tool for HER3 ?

The ones I saw in the log that recorded the flight in which your drone failed I have never saw in normal operation in healthy systems. For me it seems like trying to begin a communication but failing all the time, but I could be wrong about it.

I don’t think so. But you can use UAVCAN tab on Mission Planner in order to check communication with your module and check if you are running the latest firmware available on it.