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G-RX8 flashing red and blue

bbardon

New User
Hi, I hope someone can steer me toward a solution for this. What does it indicate when a G-RX8 flashes alternating RED and BLUE while the motor is beeping once a second?

I'm trying to set up Mike's E-Soar Plus. Have done it before on other planes, but this one is not cooperating. The problem is when I try to enter calibration mode, the Rx starts flashing red and blue, the motor is beeping once a second, and the servos behave oddly. Some move to an endpoint, some don't, but all start marching in tiny increments, once a second, toward some unknown destination. Once in a while they will suddenly move a large amount to some new random position. This continues until I remove power.

Here's what I've got:
Taranis X9D running EdgeTX 2.9
Frsky G-RX8 receiver running UNI
EMAX ES3352 digital servos
E-Soar 3.0 template

Here's what I've done:
Calibrated radio internally.
Bound Rx in PWM CH1-8 with telem mode. Green LED is present.
Calibrated throttle to ESC. Correct beeps heard.
Set some ESC options using Tx. Brake normal, brake force 3, cutoff voltage 3.2, BEC voltage 5.2, startup soft.
Began the E-Soar setup by setting servo directions. OK.
Going into calibration mode (confirmed by voice output) to start adjusting Lf4, that's when flashing red and blue begins, servos snap to new weird positions, beeping starts, and the noise of servos moving about once a second is seen and heard. They seem to heading from wherever they ran to, back to the expected positions, one small increment at a time.

I don't think it's just that things aren't calibrated yet. For example, the rudder goes hard right and stays there. Even an uncalibrated rudder would be roughly in the center, wouldn't it? Correct servo in correct channel is verified with the first step of setting direction of movement. Tx and Rx batteries are charged.
 
Please describe exactly how the LEDs are flashing. For example, does the blue LED light, then the red LED light, then the blue LED go off, then the red LED go off?

Mike
 
It's like red for one beat, blue for three, and repeat. Here's a short video. What my hand unfortunately obscures is that I'm pulling the right stick down and left, and toggling SH.

 
Only time i have ever had weird flashing lights on a frsky rx was when i had reverse polarity going to the rx. IE red to black black to red
 
What revision of firmware do you have in the G-RX8?
I reckon the green LED comes very briefly between the red and blue LEDS. It looks like the Rx receives a packet OK, probably transmits some telemetry, then gets something very odd happening causing the blue LED to come on (there are a couple of very fatal errors that could cause this), then the Rx restarts.
I just flashed a X9D (not plus) with openTx 2.3.15 (I normally use erskyTx) downloaded the ESOAR template and put that on the Tx (no changes), then tried the CAL mode with my G-RX8 and it didn't cause any problems. I have UNI V80 on the G-RX8.
Perhaps post your model file (.otx) and specify exactly where you have your switches, pots and sticks set when you get the problem, so I may try to reproduce it.

Mike
 
Please check your power source for the Rx.
At power on, the G-RX8 turns the blue LED on for a second or two. It looks to me that your Rx is powering on, starts running (red LED comes on), receives data (red LED off, green LED on) then gets a power drop causing it to restart.

Mike
 
Have flashed EdgeTX 2.10.0 to the X9D and UNI_RXxR_GRXx_80sm.frk to the G-RX8. Replaced SD card with a new one. Re-downloaded E-Soar, extracted and copied in via Companion.

Bound the Rx to the new E-Soar instance and ran through the paces. Had a green light, surfaces moving correctly. Went to CAL mode and the same problem still exists. However, I shut everything off, and started back up but instead of connecting my 1200mah battery to the ESC, I connected a 4.8v NiMH pack directly to the Rx. Then, NO problem. So I suspect the ESC.

I'm going to reset the ESC to default settings and try again. If that fails, I'll order a new ESC. This is a HobbyWing 20A. Is there a better choice for a 6-servo glider?
 
Replacement ESC fixed all the problems with the flight system. Which is great, because now I can move on... to the next problem. <sigh>

Only getting 100 watts from a 3s 1200mah 25-50C pack, with a 10x5 prop on an EMAX GT2215 motor. According to the motor spec sheet it should about twice that. My watt meter shows voltage drop from 12.6 to 11.4 at full throttle. That seems like too much to me. These are old-new packs, bought a year ago but never used until now. They were stored at 3.6V per cell, but not cycled at all during that year.

Will a higher C-rated pack help here? I'm nowhere near even the 25C current draw, but I know those figures are "optimistic." Anyone know a battery vendor where I can specify dimensions in a search? I have a glider with limits on battery dimensions.
 
Pulled the old motor out. It was a GT2215/12, meaning only 905KV. So it was performing to spec. Getting one with a longer stator and higher KV that should get me closer to 200 watts.
 
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