Sunday 25 October 2020

RC, FPV and FCB terms


FPV - First Person View. Flying while watching an onboard video transmission.

VTx VRx - Video transmitter and video receiver used for FPV.

FCB - Flight Control Board (eg. Matek F405-Wing)

MCU - Microcontroller Unit (Main processor chip of FCB eg. STM32F405)


IMU - Inertial Measurement Unit (Gyro and Accelerometer chip eg. MPU 6000)


Baro - Barometer Altitude sensor (eg. BMP280)


Magnetometer - Electronic Compass (eg QMC5883)


DFU - Direct Firmware Upload (Processor Mode which allows firmware upload)


MSP - Multiwii Serial Protocol. Communication protocol used by INAV and FCBs. MSP came from Multiwii software, which was derived from the Nintendo Wii Game Controller. 


Serial Port - Pins or pads on FCBs for connecting external devices. Serial means all channel signals use the same wire. 


UART - Universal Asynchronous Receiver Transmitter Serial port. Pins or pads where UART devices (GPS, RC receivers, camera controls) connect to the FCB. Pins labelled - Ground Voltage RX TX. RX from the device connects to TX on the FCB


I2C or I squared C - Inter Integrated Circuit Serial port. Pins or pads where I2C devices (compass, OLED screen) connect to the FCB. Pins labelled - Ground Voltage SDA SCL


SPI - Serial Peripheral Interface. Connection interface for onboard devices like SD card reader and barometer


ADC - Analog to Digital converter. FCB component that converts a varying voltage input to a digital output. Used for displaying battery voltage, current, analog airspeed sensor and analog RSSI values.


Soft Serial - Extra Serial port enabled in software, by repurposing spare UARTs pins. Eg Smart Port telemetry connection to an unused TX pin.


Vbat - Flight battery Voltage. May be filtered on some FCBs to reduce video interference


OSD - On Screen Display


GNSS - Global Navigation Satellite System (Commonly called GPS, but GPS only refers to the US satellite system. Other GNSS systems include Galileo, GLONASS)


OLED - Organic Light Emitting Diode used in OLED data display screens and some FPV goggles


RSSI - Received Signal Strength Indicator. A number representing the strength of an RC signal at the receiver.


LQ - Link Quality. A number representing the strength and quality of an RC signal.


LFR - Lost Frame Rate % - Percentage of lost frames in an RC Signal


PWM - Pulse Width Modulation. Basic RC signal protocol which uses an individual wire for each channel signal. Used for connecting servos to a receiver or receiver to FCB.


PPM or CPPM - Pulse Position Modulation. Serial RC protocol. Used for connecting a receiver to FCB, or RF module to a transmitter. All channel signals on one wire


SBUS - FrSKY and Futaba Serial RC protocol. Used for connecting a receiver to FCB, or RF module to a transmitter. All channel signals on one wire. 


S-Port - FrSKY Smart Port Telemetry system. Extra socket found on FrSky receivers to connect telemetry sensors.


F-Port - FrSKY SBUS and SPort combined. RC and telemetry signals on one wire.


F-Bus - F-Port version 2


Tandem (TD) - FrSKY RC system which uses 2.4GHz and 900MHz RF simultaneously


iBUS - FlySKY Serial RC protocol. All channel signals on one wire.


CRSF - Crossfire. Team Black Sheep long range RC protocol. Similar to FPort.


R9 - FrSKY Long range RC 900MHz protocol 


ExpressLRS (ELRS) - Open Source, Long range, low latency RC system. 2.4GHz or 900MHz versions. Uses the CRSF protocol.


ESC - Electronic Speed Controller


BEC - Battery eliminator circuit. Confusing term for a voltage regulator found on ESCs and FCBs. BECs reduce and smooth out the battery voltage for use by lower voltage devices. Eg. 9V or 5V for FPV gear, 5, 6 or 7.2V for servos.