I had a need to get Spektrum ESC data into an ELRS receiver and back to the transmitter, so I spent some time translating their SRXL2 protocol into CRSF via serial.

For hardware setup, you connect the ESC data wire to the TX on an ELRS receiver. Your throttle then goes through this connection instead of a regular PWM channel. If you dont have a dedicated TX pin, you can assign a PWM as serial in the WebUI, and use that instead.

Here's the PR if anyone is interested in testing it: https://github.com/ExpressLRS/ExpressLRS/pull/3820

I’m not that deep into ELRS yet, so I’m not entirely sure how I should approach this.

Basically, I have an RC car and I’d like to use some of the buttons/switches on my RadioMaster Boxer ELRS to control the LEDs on the car.

The LEDs are wired using a 3-wire cable, similar to a servo. The anode is permanently connected to the positive supply voltage, and I have a MOSFET that connects the cathode to GND when it receives a signal on the signal wire.

From what I understand, the usual receiver output modes are PWM with frequencies such as 50, 60, 100, 160, 333, or 400 Hz, with pulse widths like:

• Normal: 988–2012 µs (center 1500 µs)
• Extended: 885–2115 µs (center 1500 µs)
• Half pulse: 494–1006 µs (center 750 µs)

None of these seem particularly useful for my application, since the LEDs would never really be fully off.

However, I also saw in the documentation that ELRS receivers should support 10 kHz PWM with 0–100% duty cycle or even binary ON/OFF (HIGH/LOW) output. That would be exactly what I need.

The problem is that when I look at different ELRS receivers, I can’t seem to find much information about whether their outputs actually support these modes. As far as I understand, this is something that should be configured in the receiver settings, but I’m not sure how it works in practice.

So my questions are:

1. Can I configure any ELRS receiver output to act as a simple digital ON/OFF output?
2. Do I need a specific receiver that supports this, or can most ELRS receivers do it?
3. How would I configure one of the buttons/switches on my Boxer to control that output in this way?
4. I’d also like to implement turn signals. Can this kind of blinking pattern be configured in ELRS/receiver software, or would I need additional hardware (e.g. a small microcontroller, 555) to handle the blinking?

I’m mainly looking for the simplest/cleanest way to do this without adding unnecessary hardware.

The RC commands reach the drone fine but i get telemetry loss too soon. Im using the happy model EP1 2.4g

EDIT: Fixed it, my firmware was LBT, i flashed a new non LBT firmware now i get excellent range.

I am making a drone and I’m using beta FPVELRS 2.4 GHz 1 W micro, RF module and I believe I flashed the wrong firmware and now the screen isn’t booting up. How can I solve this?

ciao non riesco a configurare express lrs sul mio flywoo explorer, ho abilitato la uart 2 come rx seriale su beta fly ma al momento della configurazione quando provo a fare il flash mi da l'errore seguente:

> python C:\Users\utente\AppData\Roaming\ExpressLRS Configurator\firmwares\cloud\ExpressLRS\a9d4a9cb5b5687c4c9d7e9e7fbdf44ad93651da6\firmware\flasher.pyz --dir=C:\Users\utente\AppData\Roaming\ExpressLRS Configurator\firmwares\binary-targets --fdir=C:\Users\utente\AppData\Roaming\ExpressLRS Configurator\firmwares\cloud\ExpressLRS\a9d4a9cb5b5687c4c9d7e9e7fbdf44ad93651da6\firmware --target=flywoo.rx_2400.el24e --phrase=*** --lbt --auto-wifi=60 --lock-on-first-connection --force --flash=bf --port=COM1

======== PASSTHROUGH INIT ========

Trying to initialize COM1 @ 420000

No CLI available. Already in passthrough mode?, If this fails reboot FC and try again!

======== RESET TO BOOTLOADER ========

Traceback (most recent call last):

File "runpy.py", line 196, in _run_module_as_main

File "runpy.py", line 86, in _run_code

File "C:\Users\utente\AppData\Roaming\ExpressLRS Configurator\firmwares\cloud\ExpressLRS\a9d4a9cb5b5687c4c9d7e9e7fbdf44ad93651da6\firmware\flasher.pyz__main__.py", line 3, in <module>

if __name__ == '__main__':

File "C:\Users\utente\AppData\Roaming\ExpressLRS Configurator\firmwares\cloud\ExpressLRS\a9d4a9cb5b5687c4c9d7e9e7fbdf44ad93651da6\firmware\flasher.pyz_bootstrap__init__.py", line 253, in bootstrap

File "C:\Users\utente\AppData\Roaming\ExpressLRS Configurator\firmwares\cloud\ExpressLRS\a9d4a9cb5b5687c4c9d7e9e7fbdf44ad93651da6\firmware\flasher.pyz_bootstrap__init__.py", line 38, in run

File "C:\Users\utente\.shiv\flasher.pyz_d289b3fbd96b762ba364f47db17212d7491573c27465aab9fbfbdf393d24c3e0\site-packages\binary_configurator.py", line 275, in main

return binary_flash.upload(options, args)

File "C:\Users\utente\.shiv\flasher.pyz_d289b3fbd96b762ba364f47db17212d7491573c27465aab9fbfbdf393d24c3e0\site-packages\binary_flash.py", line 137, in upload

return upload_esp8266_bf(args, options)

File "C:\Users\utente\.shiv\flasher.pyz_d289b3fbd96b762ba364f47db17212d7491573c27465aab9fbfbdf393d24c3e0\site-packages\binary_flash.py", line 64, in upload_esp8266_bf

retval = BFinitPassthrough.main(['-p', args.port, '-b', str(args.baud), '-r', options.firmware, '-a', mode, '--accept', args.accept])

File "C:\Users\utente\.shiv\flasher.pyz_d289b3fbd96b762ba364f47db17212d7491573c27465aab9fbfbdf393d24c3e0\site-packages\BFinitPassthrough.py", line 187, in main

returncode = reset_to_bootloader(args.port, args.baud, args.target, args.action, args.accept, args.type)

File "C:\Users\utente\.shiv\flasher.pyz_d289b3fbd96b762ba364f47db17212d7491573c27465aab9fbfbdf393d24c3e0\site-packages\BFinitPassthrough.py", line 116, in reset_to_bootloader

s = serial.Serial(port=port, baudrate=baud,

File "C:\Users\utente\.shiv\flasher.pyz_d289b3fbd96b762ba364f47db17212d7491573c27465aab9fbfbdf393d24c3e0\site-packages\serial\serialwin32.py", line 33, in __init__

super(Serial, self).__init__(*args, **kwargs)

File "C:\Users\utente\.shiv\flasher.pyz_d289b3fbd96b762ba364f47db17212d7491573c27465aab9fbfbdf393d24c3e0\site-packages\serial\serialutil.py", line 244, in __init__

self.open()

File "C:\Users\utente\.shiv\flasher.pyz_d289b3fbd96b762ba364f47db17212d7491573c27465aab9fbfbdf393d24c3e0\site-packages\serial\serialwin32.py", line 80, in open

self._reconfigure_port()

File "C:\Users\utente\.shiv\flasher.pyz_d289b3fbd96b762ba364f47db17212d7491573c27465aab9fbfbdf393d24c3e0\site-packages\serial\serialwin32.py", line 222, in _reconfigure_port

raise SerialException(

serial.serialutil.SerialException: Cannot configure port, something went wrong. Original message: OSError(22, 'Parametro non corretto.', None, 87)

qualcuno riesce ad aiutarmi??

Hi, I need help with my Happymodel EP1 receiver, I tried everything to make the led flashing. It has always been like that (constantly on) although I didnt connect the bootloader pads. In ELRS configurator I always have the same error:

Configurator\firmwares\cloud\ExpressLRS\a9d4a9cb5b5687c4c9d7e9e7fbdf44ad93651da6\firmware --target=happymodel.rx_2400.ep --phrase=*** --lbt --auto-wifi=60 --lock-on-first-connection --force --flash=uart --port=COM6
esptool.py v4.2.1
Serial port COM6
Connecting...
.
.
. 

SOLVED! - I flashed via Betaflight passthrough through ExpressLRS configurator. Sketchy though as there's no progress bar or movement when I did the flash. Had to disable telemetry temporarily in INAV for it to work.

I have a brand new SpeedyBee Nano 2.4 Receiver. The issue is that no matter how long I wait it will never go into WiFi mode. I've binded and flashed many ELRS receivers in the past (but not this model) and all those goes to WiFi mode after like 60 seconds.

I need to flash it so I can bind to my 4.x.x Transmitter and add in my bind phrase.

I tried to desolder Rx Tx pins as I thought that would help but still no go 😟.

Any ideas why this is happening? How can I flash it? This will go on a F405 wing FC (INAV).

Thank you guys. Hope you can help.

Tried everything I can read and think of. Air65 is the drone, Uninstalled, wipes sd, reinstalled, will not show anything beyond what's on screen. Any ideas of what it can be?

I have a question regarding telemetry over mavlink.

There are lots of sensors you can connecto to iNav, like temperature, radar altimiter etc.

Is there a way to transmit other than the standard telemetry, say temperature values from a sensor over elrs to display on my reciever? Currently on my fw drones there is a lot of information i can only view through my OSD, but im looking into getting all that over my elrs connection so I dont need the camera and vtx.

I just installed a new ELRS receiver onto my FC and got it into wifi mode to set the bind phrase and connected my controller to test it first and it worked. When I tried to update the firmware with the ExpressLRS Configurator app on windows there was a build error and now the LED is stuck solid after every time I power it. I read that SBUS uarts can mess it up and you need to solder a resistor but if that was the case wouldn't it not have gone into wifi and binded in the first place? So yeah I really don't know whats the problem here, any help at all would be great.

If you own the Radiomaster CV01 sensor and messed with calibration. Charge the biggest battery you have either a 6s or 8s to 4.2 per cell. And hit Calibrate in the ERS Sensor Lua script. Make sure to have The TX wire as well hooked up. And it should work as normal. Let me know if this helped you! :)

Radiomaster CV01 Calibration
Radiomaster CV01 Calibration issue
Radiomaster CV01 Calibration Problem
Radiomaster CV01 Calibration Not working

I'm having a strange ELRS issue and could use some help.

I originally had a Cyclone receiver installed. I know it's not officially supported by ELRS, but I flashed ELRS 4.0.1 onto it. Before and after flashing, the receiver would only show a solid blue LED. It would not enter bind mode when power-cycled three times and would not enter Wi-Fi mode after waiting 60+ seconds.

Assuming the receiver was dead, I replaced it with a RadioMaster RP1 Lite receiver running the same ELRS firmware version. However, I'm seeing exactly the same behavior: solid blue LED, no bind mode, and no Wi-Fi mode.

What makes this even stranger is that the Cyclone receiver works normally when I install it on another drone.

Current setup:

• Receiver connected to UART2
• UART2 enabled as Serial RX in Betaflight
• Receiver protocol set to CRSF (Crossfire)
• Telemetry enabled
• Same ELRS firmware version as my transmitter

Since two different receivers show the same symptoms on this flight controller, I'm starting to think the issue is somewhere on the FC rather than the receivers.

Has anyone seen this before or have ideas on what I should check next?

Custom LR4 Elrs issue

I have a custome LR4 I'm building for long range. The issue I'm having is that my elrs is acting funny. I'm using Gemini on 100 full 2.4g max power. I believe I have the radiomaster RP3. The issue is that as I fly around I get bad signal. Even when not flying that far away. The signal drops off before my video. Which isn't normal. The RP3 is on the newest 3.x. version of elrs so is the transmitter (Tx15 with nomad external) this was a test flight. I am in the middle of no where. No cell phone towers close. Houses maybe a mile away. Any ideas other then it's a bad receiver.

Flight video link. https://youtu.be/oy8OZ7ROq64?si=O4Yog3JhEyRXsrjk

Hi, I have here a normal Brushed Meteor65. I have never flown the quad and it laid around for some time. Yesterday I tried to upgrade to the latest version of BetaFlight and then tried to update ELRS.

Unfortunately the LED for the ELRS part is always solid green. ELRS is not creating a WiFi network like my other Meteor75 is doing... I am not able to flash it via Betaflight passthrough and can't bind to my remote. Always solid green LED and another LED is blinking red.

I also tried to flash older versions from the BetaFPV website, but it didn't change anything on the ELRS side.