fix(mlink): sometimes need > 1s timeout for MLink telem

[mha1]

... if all MLink addresses (telemetry items) are used to avoid telemetry lost/telemetry recovered mania

tested with MPM/MLink and PPM/MLink

@pfeerick please consider cherry picking this into 2.10.x

[inventor7777]

If this would work for all protocols, I definitely support this at least being part of 2.11. Nothing more annoying than getting just a liiitttle bit out of range of telemetry and the radio absolutely losing its mind :-)

[pfeerick]

If this would work for all protocols, I definitely support this at least being part of 2.11. Nothing more annoying than getting just a liiitttle bit out of range of telemetry and the radio absolutely losing its mind :-)

I don't think that is the problem here ... but more that it can take longer than the protocol specific telemetry timeout if there is too much data to send (ok, depending on point of view receive) ... hence the increase in the timeout specifically for MLink... at the moment it will be going nuts because it is taking too long for the data to come in, which makes the alarm checks think that there is no telemetry, rather than that it was interrupted.

btw, this also makes it match the MLink RSSI update rate timeout ;)

[mha1]

@pfeerick Thanks for merging this.

You are quite right with your assessment. MLink is a masterpiece of German engineering. It can transfer a maximum of 16 telemetry items (Doh!) and sends two telemetry items every 100ms (even more Doh!). Makes a worst case of 800ms for LQI being sent if all 16 telemetry items are configured. But this makes Vario data also almost unusable at 800ms update rate. To circumvent the problem MLink can define one priority telemetry item. If configured MLink sends the priority telemetry item every 100ms plus one of the others. Having configured a priority item will pushes LQI to the real worst case 15*100ms = 1.5s update rate. This is the reason why 1s is not be enough to cover the worst case scenario having more than 9ish telemetry items plus one priority item configured.

[inventor7777]

I don't think that is the problem here

Ah! Makes sense. I need to read more thoroughly next time 🙄