Hello, i have a very old plane laying around and decided to switch the rx to an elrs one. I have bound the rx and tx. The rx is elrs version 3.5.3 and the tx is 3.0.0. It does not haven fc. When i power on the plane and the tc i have a connection, but when i move my sticks i get no response from the plane. Thanks for your help! Please let me know if you need more information.
#no inputs with pwm rx
jagged meadow
trail waspBOT
Hello, i have a very old plane laying around and decided to switch the rx to an ...
✨AI-Generated response✨
It seems your transmitter and receiver versions are compatible (both v3.x) and you have a connection, but the servos aren't responding. This often points to a configuration issue on the PWM receiver itself.
- Check Channel Mapping: By default, TX Channel 1 maps to PWM Output 1, CH2 to Output 2, and so on. AUX1/CH5 is often only a 2-position channel by default. You likely need to remap the channels using the receiver's WebUI or the ExpressLRS Lua script under "Other Devices" > "[Your RX]" > "Output Mapping". Ensure the TX channels you're using (e.g., Throttle, Aileron) are mapped to the correct PWM output pins connected to your servos. See the PWM Receivers page and the Lua Script Guide for details.
- Check Output Mode: Verify that the output pins are set to a PWM mode (e.g., 50Hz PWM) suitable for your servos, also via the WebUI or Lua script.
- Use Full Res Mode: For best performance with PWM servos, consider using a Full Resolution packet rate (like 100Hz Full Res) on your transmitter, as detailed on the Switch Configs page.
- Servo Power: Ensure your servos are receiving adequate power. PWM receivers typically pass power through but don't supply it themselves; servos usually need power from a BEC or separate battery.
- Update Firmware: While v3.0 and v3.5 should work together, updating both your TX and RX to the same latest 3.x version is recommended for the best compatibility. See the updating guides.
If you still have issues, checking the receiver's WebUI (https://expresslrs.org/quick-start/webui/) is often the easiest way to configure PWM outputs.
-# {'cause': 'thread creation'}
jagged meadow
i cant connect tx to rx because it has no fc. Output pins are set to pwm. Servos receive power because when i power the plane on the servos move once.
Can i update my tx over wifi, because i see no option in the elrs configurator for that for the tx.
forest hazel
Show a screenshot of the RX and TX !webui
late etherBOT
Connect to your transmitter's or receiver's WiFi network to access the web UI:
forest hazel
What radio do you have?
jagged meadow
i have a taranis qx 7 acces with the 2.4ghz namimno elrs module
forest hazel
i have a taranis qx 7 acces with the 2.4ghz namimno elrs module
Flashing guide here: https://www.expresslrs.org/quick-start/transmitters/flash2400/
I recommend flashing via USB
forest hazel
Show both the options and model tabs for the RX please
jagged meadow
this is from the rx
forest hazel
You have model match enabled on the receiver
Open the ELRS lua with the receiver connected, and turn model match on
Turn it off again if you don't want to use it
jagged meadow
i want it enabled and the rx light is steady and doesnt blink so it is succesfully bound, isnt it. at first i had a model mismatch but fixed it then
whenever i try to flash the firmware on the tx, it says update aborted and the wifi just shuts down
it also says syntax error on my tx
jagged meadow
Open the ELRS lua with the receiver connected, and turn model match on
i did that
forest hazel
whenever i try to flash the firmware on the tx, it says update aborted and the w...
Post the !log
forest hazel
i want it enabled and the rx light is steady and doesnt blink so it is succesful...
Disable model match for now while troubleshooting
jagged meadow
jagged meadow
Disable model match for now while troubleshooting
ok i will do that
forest hazel
This doesn't look like USB
jagged meadow
no it is wifi. i forgot u said i shou8ld try with usb
will do that now
should i plug in the module directly? When i do that nothing happnes
forest hazel
Are you following the flashing guide?
jagged meadow
yes
jagged meadow
yep
jagged meadow
That is literally step 1
just wanted to make sure cause nothing happened
forest hazel
What do you mean nothing happened? What does it show up as in device manager?
jagged meadow
im just stupid im sorry. It worked now. I thought it didnt show up in the device manager even thoughj it did
forest hazel
Servos working now?
jagged meadow
no, sadly not. I will turn off model match now
still got telemetry but no movement off the servos or the motor whatsoever
forest hazel
Can you show the servo wiring?
jagged meadow
yes, wait
forest hazel
You have the sticks mapped properly to outputs?
There is movement in the channel monitor on your radio when you move the sticks?
jagged meadow
You have the sticks mapped properly to outputs?
i think so, yes
forest hazel
Can you also show the ELRS lua on the radio?
jagged meadow
There is movement in the channel monitor on your radio when you move the sticks?
yes
is this enough of the wiring?
forest hazel
Are two of the servos plugged in backwards?
glass orchid
they are all backwards
jagged meadow
thank you very much! Everything works now, except my elevator but that is probably due to some channel mapping error. I will try to fix it later. I really appreciate your help!
forest hazel
thank you very much! Everything works now, except my elevator but that is proba...
Ch5 is a 1 bit arm channel. Remap ch5 output on the receiver to channel 6, and use one of the full res modes
jagged meadow
i have elevator on output 3 and rudder on output 4. Elevator doesnt work. If i switch those elevator works and rudder which is now on ouput 3 doesnt. Does this mean output 3 doesnt work?