ModalAI Forum

before running esptool ensure px4 is disabled with "systemctl status voxl-px4"
if it's still running try disabling it again and rebooting.
It must be disabled from boot for esptool to work.
Then after the update is successful you can re-nable px4 and reboot

Once the update is complete the receiver led should start blinking and the voxl-elrs ping command should respond

@Hector-Gutierrez

It should always be supported, there's instances where an update fails and you'll need to re-enter bootloader mode to fix it.
bootloader mode should be recoverable from the drone. Here's some tips to try and recover it.

this may take a few attempts until you get it right

try these steps to see if it will atleast communicate in bootloader mode. sometimes the esptool can take a minute to respond

• voxl-configure-px4 disable
• Turn off drone
• Hold down the receiver's boot button, Power on the drone while holding the button
• Keep holding for 1-2 second after power on, then release
• receiver led should be solid blue (after following these steps it should be in bootloader mode)
• run this command to check if receiver is alive: "python3 -m esptool --port /dev/slpi-uart-7 --chip ESP8266 --baud 115200 --before no_reset chip_id"
• If that works then proceed with update.
• "python3 -m esptool --port /dev/slpi-uart-7 --chip ESP8266
  --baud 115200 --before no_reset --after soft_reset
  write_flash 0x00 /usr/share/modalai/voxl-elrs/firmware/3.5.3.21/BETAFPV_900_RX_via_UART/BETAFPV_900_RX-3.5.3.21-20251205.bin"

@Hector-Gutierrez hey I've been able to recover almost all of these betafpv receivers. Is the blue led still active or has it gone completely black? Holding the button on power up should force it into bootloader mode with a solid blue light which is a good first step.