X10+v2 and ELRS

[flyingw]

Hello Jim,

It had been a long time and I hope you and your family are well.

I have been working with a new ELRS system.  I'm using a RadioMaster TX15 transmitter and several RadioMaster receivers.  I got an 8-channel ER8GV receiver that I want to put into my sailplane that currently has an RFU and X10+v1.

To begin I configured an X10+v2 to take SBUS as its input.

Then I configured one of the PWM servo outputs on the ER8GV receiver to be a serial port and to output SBUS.  I connected it all up and powered on and it worked.

The X10+v2 green led flickered about three times per second.

I got feedback from the RCGroups ELRS forum that the SBUS errors are there because ELRS periodically sends back telemetry packets in time slots normally occupied by control packets.  My system's overall packet rate is 100Hz for 10ms frames and my telemetry ratio is 1:32.  That means it sends about three telemetry packets every second.  That could explain the three led flickers pre second.

My ELRS frame rate is set to 10ms and the receiver's PWM outputs are set to 50Hz.  The ELRS system therefore sends every other control packet to the PWM outputs.

The setup and servos seem to work, so I plan to try it out at the airfield soon.

Can you think of any reason I shouldn't fly it?

Thanks,

Paul

p.s.  Will your proposed X10+v3 take CRSF as an input?

[XPS]

Well, you are losing data, but at 100Hz it probably doesn't matter.

The X10+ V3 will support several new protocols including CRSF.

[flyingw]

Thanks Jim,

I agree that losing a small amount of data 100Hz may not matter for sport flying, but since the non-standard SBUS prevents the X10 from setting the failsafe positions I can't use it.  That's why the news about the X10+v3 supporting CRSF is encouraging.

I am learning about ELRS radios and receivers now and found a significant problem with the currently available receiver that have PWM servo outputs.

When you power up the receiver (with servos connected), the servos move un-commanded to a position about one half of their throw in random directions.  A few seconds later the transmitter and receiver engage, and then the servos move to their center and ready positions.

This problem even manifested itself on one of my planes such that the prop spins before the receiver and transmitter engage properly - I do not like that.

I just tested the XPS system with an XPS-J1 module and Nano receiver. It does the same thing: The servos move a little bit when I connect the battery to the receiver. But the Nano boots up so fast, maybe half a second for the servos to snap to their ready positions.

And, I repeated the test with an old Futaba 72MHz transmitter and receiver - it does the same thing! But, the receiver acquires the transmitter signal almost instantly (no boot up for analog electronics) so the spurious servo movement is hardly noticeable.

[XPS]

The XtremeLink system boots in about 80ms. Servos often have a small delay before they are up and running too.

[flyingw]

Jim,

As we discussed earlier in this forum, when I attempt to use an ELRS receiver that is configured to output SBUS to an X10, The X10 shows some errors, likely due to an SBUS implementation by ELRS that is non standard.  The servos worked, and I am probably losing some data, but it would probably be ok in some cases - like flying a small foam airplane.  The problem was that when operating with the non-standard SBUS from the ELRS receiver, I was not able to set the failsafe positions in the X10.

Then I tried a test:

(1) I successfully set up the failsafe positions in an X10 with the usual method using a Taranis and its XPS-J1 transmitter module while connected to an XPS Nano receiver outputting Xtreme protocol to the X10

(2) Then I disconnected the Nano Rx and reconfigured the X10 to take SBUS as its serial input

(3) Then I plugged the ELRS receiver (outputting SBUS) into the X10 and powered up the ELRS transmitter and X10 and got a good connection with the servos working

(4) With the ELRS receiver now in play I powered down the ELRS transmitter and the X10s failsafe positions still worked the way I programmed them earlier with the Nano Rx

Do you think that the X10s failsafe settings are persistent and reliable when used in this manner?

I just read your X10+v2 manual again and found this statement:  "Only repeating this procedure or performing a factory reset will change the failsafe position settings."

Thanks,

Paul

[XPS]

If you have the X10+ setup to control the failsafe positions then that is what will happen during a failsafe. The only issue you might run into is what the receiver itself does. I have seen various receivers continue to send a the SBUS packet with its own failsafe positions when the signal from the transmitter is lost. There is nothing the X10+ can do about that because the input signal is what it monitors.

[flyingw]

I configured the ELRS receiver to send no packets when in failsafe, so theoretically it shouldn't. Thanks for the information.