Skip to content


Info Banner

Technical words with explanations

Below you can find a list of terms you might not be sure about, as well as some common abbreviations:

  • BL: Bootloader, loads the FW
  • CRSF: TBS Crossfire, more specifically in our case most often referring to the communication protocol between TX and TX module and RX and FC respectively
  • ESC: Electronic Speed Controller
  • FC: Flight Controller
  • FW: Firmware
  • LQ: Link Quality, percentage of expected packets received. Our preferred method of measuring the quality of the control link
  • Lua: Means "Moon" in Portuguese. As such, Lua is the correct way to write and not all uppercase. The ExpressLRS Lua script can be installed on a OpenTX radio, to easily alter TX parameters like Packet rate, Telemetry ratio and Output power. But also shows if the radio (OpenTX) is communicating correctly with the module. ( e.g. 0:50, 0:150, 0:200 and so on.)
  • MCU: Micro Controller Unit, generally denotes an embedded system controller as opposed to big iron CPU
  • OSD: On Screen Display, refer to this page for instructions for setup in BF
  • OTA: Update your device Over The Air (WiFi)
  • OTX: OpenTX
  • RSSI: Received Signal Strength Indicator, "arbitrary" scaled version of RSSI dBm or LQ. Signal Health: LQI and RSSI Explained
  • RSSI dBm: Measure of power level measured in dBm. Basically, how strong the signal being received is
  • S.Port: SmartPort, sometimes referred to as sport. FrSky "telemetry" protocol. The S.Port also gets used for updating FrSky receivers.

To be continued.