Servers by jDrones

MAVLink to HoTT telemetry converter for Graupner RC users

(Kay Spranger) #21

Is it possible that APM does not send mavlink data on its own and I would need a minim OSD for instance to get the stream going?

(Mike Boland) #22

I just checked those settings on a 3DR APM 2.6 and I could get no data.

When I get a chance I will hook a radio up and see if MavLink on that port needs to be initiated, which I vaguely recall was the case with 3.2.1

However I did note that I was getting Flight mode and arming state, just no other data.

(Kay Spranger) #23

Hi Mike,

that would be really helpful. I will try getting data from another APM tonight.

I can’t seem to even get the flight modes :-/

(Mike Boland) #24

It seems that 3.2.1 on APM must not initiate MavLink on the port until it gets a request to do so.

I hooked up the MavToHOTT data line 'T’ed to the Tx of a radio.
Boot the APM and no HOTT data, but connect with a radio and the HOTT data starts flowing.
I do recall this was an issue with some of the OSD’s until they included an initiate MavLink command on bootup.

I do know there is a firmware update for the MavToHOTT.
Are you using the latest?
I have downloaded it but not yet install it.

(Kay Spranger) #25

Hi Mike,

I have mavlink2hott 1.4.3 installed.

So you mean it could work if I set up, say a minim OSD and hookup the Arduino and the OSD both on the Tx of the telemetry port, while the OSD also is hooked up and sends a request through the Rx of the APM?

Best regards

(Mike Boland) #26

@Kay_Hawaii not all OSD’s actually request data.
I know some versions definitely do not request data and rely on the Telem1 being connected to a radio.
This is why they work with only the Tx line connected.

(Kay Spranger) #27

Everybody, thank you all for your help and support,

I am happy to report success.

I had contacted Michel Kosloff, the developer of the mavlink2hott firmware and after some deliberation and a video I sent him, he suggested not using an arduino with onboard USB, as I had, but rather an arduino pro mini.

That worked like a charm!

Best regards

(alcala) #28

could somebody send me the hex file (the link is broken)

many thanks


(Mike Boland) #29

The Link is

(alcala) #30

Thanks mike
When i type the link i have a 404 error


(zdv770) #32

Version 1.4.5 update is available.
Some small bugs fixed (eg. voice alarms are now suppressed until armed)
Welcome to download at