Servers by jDrones

MatekF405-Wing - No telemetry

(Don Sebastian) #1

I got a problem with the Matek F405 Wing.
If only one Lipo battery is connected, no telemetry is transmitted.
I start the FC by connecting USB (notebook mission planner) and then connect the battery to the telemetry connection. (also without USB)
I already tried different UARTS and another receiver.
the same receiver with the same level converter works right away on an old Pixhawk.
Except for the “starting difficulties” the FC works flawlessly.
RC: Xlite with R9MM+ with Flex firmware

Andruplane stable-3.9.8
I use the UART Option 10 and the Yapuu telemetry cable.

(Henry Wurzburg aka ATXHELI) #2

From your description, I am not sure exactly how everything is connected…but a couple of notes…

  1. When only USB is connected to the FC, all the uart and i2c signal outputs are active, but none of the 5V outputs are active so UART and Compass, etc wont be working…and if you subsequently apply main battery to the FC, then the compass of the BN-880 will fail to start up since its signal lines are toggling, when it was not powered…but the BN-880’s GPS does not have a problem with the TX/RX lines wiggling before the main power to the GPS is turned on, so it will start up fine…
  2. I assume you are using an inverter cable between the UART and the RX to obtain an SPort connection…in that case the MAX2323 inverter in the cable can “latch-up” and not only not work, but get very hot, if you power via USB and then apply main lipo to the FC…again because the UART outputs are wiggling before power is applied to the inverter from the FC’s 5V source derived exclusively from the main LIPO, not when USB powered only…

Powering up via the main battery first, then attaching USB will allow everything to work…ie Compass and FRSKY Sport inverter cable…

but I am just guessing because you havent provided exact connection information…

(Don Sebastian) #3

Thanks for your answer.
But that’s only half true.
UART2 (RX) already gets power when only USB is connected. (The transmitter already has a link)
UART6 (telemetry) seems to have nothing yet
UART3 (GPS has no power)
Compass and other I2C devices I had not yet connected to the FC. I can’t say anything about that yet.
I don’t know if there is a MAX 232 in the cable, but I suspect it is.

No, it’s the other way around. I have to connect USB first and then the battery, then I can remove USB again.
Should I install a 6V capacitor on the inverter cable?

(Henry Wurzburg aka ATXHELI) #4

the power in the SBUS row is not 5V… its 4.5V , the one below RX2 is 3.3V,and both are derived from either USB or 5V regulator, neither is the 5V derived from VBAT and labelled elsewhere on the board…

you mention “only one LIPO”…how many are used and how are they connected? if you give a complete connection description/diagram, we may be able to help more…

if the FC and inverter cable are powered, everything cabled correctly, and FC params correct, the only way you are not getting telem to the RX is if the inverter cable is latched up…

and if you have the FC running before you attach the LIPO (USB or otherwise), the compass, when attached, will not function depending on chip and circuit layout used…

(Don Sebastian) #5

Only a 3S Lipo is used.

as I said, if the battery is connected first, telemetry does not work.

Startup aid via USB, and everything runs correctly.