ExpressLRS¶

Wiring¶

ep wiring

Flashing¶

Link to the ExpressLRS HappyModel EP documentation

My usual settings¶

250Hz packet rate
100mW power
ADC filtering off in Radio (Sys / Hardware)

RSSI in DJI OSD setup¶

You need Betaflight 4.2+ to format the new RFMD:LQ% in the LQ OSD element.

On Betaflight configuration tab, disable RSSI_ADC
On Betaflight receiver tab, set RSSI Channel to AUX 12

Note

AUX12/ch16 is set as the "RSSI Channel" - Displays the RSSI dBm scaled as a percentage from the current Sensitivity Limit to -50dBm and is a decent indicator of how much range is left before the LQI cliff (0 here = Sensitivity Limit).

On Betaflight OSD, activate the RSSI element, you can setup a warning to something like 30 since the AUX12 is a percentage trying to tell you how much range is left on your link.

LQ warning thresholds setup¶

On the radio, get to the ELRS Lua script
Check your packet rate setting, you'll see a dbm threshold in parenthesis (say 108dBm for 250Hz for example)
On Betaflight OSD, activate RSSI dBm warning
On Betaflight CLI, set the RSS dBm alarm to the dBm threshold from your package rate + 10 (-108 + 10 = -98 in our example)

set osd_rssi_dbm_alarm = -98
save

Note

There is no real low threshold for LQ since it greatly depends on what you fly and how acceptable it is for you that some of your packets do not get through.

HappyModel EP2¶

Is your ceramic antenna defective?¶

Switch your power to 10mW on the radio
Get your radio and receiver about 1 meter away
On your radio, get to your Telemetry page, the 1RSS sensor value should be no worse than 60-65 dB
Of course, the lower the dB the better