OSD functionality is provided for on-board OSDs using MAX7456-type chips and external MSP based OSDs, including DJI Goggles, and goggles using DisplayPort. This enables overlay of FC data on the video. Once enabled, it uses various panel items that can individually be set active and positioned on the screen using respective parameters. It allows to setup multiple screen layouts and switch between those using a spare RC channel. It also allows the display and change of sets of parameters using stick gestures or RC transmitters, in certain cases.


Being an integral library of ArduPilot firmware, the OSD code provides the prerequisites to be redirected to various backends other than MAX-type chipsets, including testing on SITL setups without actual autopilot- or video-hardware needed.


To enable the OSD overlay on MAX7456-type chips, set parameter: OSD_TYPE to 1, reboot and reload parameters. This exposes the whole OSD parameter group.

To set a RC channel for screen switching, use parameter OSD_CHAN.

To set the units used to display, use parameter OSD_UNITS:

  • 0 = Metric (meters,kilometers,meters/sec,kilometers/hour,degs in C)

  • 1 = Imperial (feet, miles, feet/sec, miles/hour, degs in F)

  • 2 = ArduPilot Native (meters,kilometers,meters/sec,degs in C)

  • 3 = Aviation (feet, nautical mile, feet/min, knots, degs in C)

To set vertical and horizontal display offset (space at top and left side of screen), use parameters OSD_H_OFFSET, OSD_V_OFFSET.

Several options can be set using OSD_OPTIONS (bitmask selection):

  • bit0 = Enable use of compact number+decimal point fonts

  • bit1 = Invert wind direction indicator (to point to the direction its blowing from instead of toward)

  • bit2 = Invert horizon roll direction

  • bit3 = Convert feet to miles at 5280ft instead of 10000ft

  • bit4 = Do not display crosshair

  • bit5 = Translate arrow directions when using BF font set

  • bit6 = Aviation style horizon when inverted (pitch moves horizon in opposite direction)

Several font sets are included and can be changed during runtime (and those who can build the software can customize or add additional font sets….see libraries/AP_OSD/fonts/README.md)


  • 0 = Clarity (default). A clearly visible large font

  • 1 = Clarity Medium. Good visibility, less dominant than clarity default

  • 2 = Betaflight. bf- / inav-osd default style

  • 3 = Bold. A bolder version of Betaflight

  • 4 = Digital. 80’s LED clock radio style


In firmware 4.1 and above, onboard font options might be limited on 1 MB boards to save memory for other features. However, font upload from SD card is supported. This allows the user to choose from up to 10 font files (named “font0.bin” - “font9.bin”) placed in the root directory of your SD card. Additionally, this allows the user to easily add individualized and/or customized language charsets for the onboard OSD without the need to compile individual firmware. Runtime font changing using the parameter OSD_FONT is unaffected.

MAVftp might be a convenient option to upload files to your SD card without having to physically remove it from your autopilot. Font files, font editor, and utilities to convert to a .bin file from .mcm are here. If downloading the editor or a font’s .bin file from this site, be sure to use the Download` button, rather than selecting ``Raw, and then right click saving, as you would the .mcm or .py files.

To enable the use of external MSP OSDs or DisplayPort systems see:

Second OSD

ArduPilot now supports having two OSD backends simultaneously. For example, this would be used on long range planes where a shorter range HD system like DJI or Walksnail would be used up until it reached the limit of its range, and then the pilot would switch to using an analog, lower definition, longer range system while operating at distance. In fact, it is possible to have three OSD systems running simultaneously since pure MSP OSD telemetry is active if any ONE OSD backend is running and an MSP base OSD could be attached to a serial port using MSP protocol.

A typical configuration would be to use the onboard analog video OSD system, together with a DisplayPort system. The setup would be:

  • OSD_TYPE = 1 to enable the analog system, with a long range video transmitter connected to the Video output pin of the autopilot

  • OSD_TYPE2 = 5 to enable the second DisplayPort backend

  • SERIALx_PROTOCOL = 42 for the serial port which the DJI or Walksnail VTX is connected for telemetry input to the goggles.


there are several combinations of first and second OSD type that are not allowed and will result in a pre-arm warning to change configuration. The most obvious is using two osd types of the same kind.


although both OSD systems work simultaneously, if the two OSD systems are different resolutions, you will need to setup multiple OSD screens (see below) and switch the screen layout when switching to using the different system (ie when swapping the video display being actively used). It is possible to create a single screen layout that works for both, but the advantage of the HD system would be obviously reduced.


screen item setup for HD displays may give warnings in Mission Planner about screen location parameters being out of range. Just ignore those.

Screens and screen switching

For multiple screen layouts, each parameter’s “OSD” part is trailed by a number, starting with “1” for the screen number for which the parameter applies.

  • OSDn_<ITEM>_<PARAMETER> - n represents the screen number, ITEM the displayed data item, and PARAMETER, the enable and positions parameters for this display item. OSD settings default to allowing up to 4 screens available, each optionally enabled. Displayed data items can be shown on one screen and not on others by setting its ENABLE parameter for that screen.

  • Set parameters OSDn_CHAN_MIN and OSDn_CHAN_MAX are used to adjust RC channel pwm limits to use for switching to a respective screen. Be careful not to have overlapping PWM ranges for two screens.

There are different switch-method options to meet individual RC systems switch layout requirements. These can be set by parameter: OSD_SW_METHOD. The options are:

  • 0 = switches to next screen if the set RC channel’s (OSD_CHAN) value is changed

  • 1 = directly selects a screen based on the set pwm limits for each respective screen. RC channel value must change for new pwm value to be recognized.

  • 2 = toggles screens on a low to high transition of set RC channel. keeps toggling to next screen every 1s while channel value is kept high

Panel items

Each OSD panel item uses a set of three variables to be set:

  • OSDn_<ITEM>EN - activates the respective item when set to 1.

  • OSDn_<ITEM>_X and OSDn_<ITEM>_Y set the horizontal and vertical position of the item, starting with X = 0 and Y = 0 in the upper left corner of your screen.


The typical MAXChip based OSD screen has a visible matrix of 30 horizontal x 13 vertical chars in NTSC standard, while PAL standard has 16 vertical chars. The OSD code enables auto-detection of NTSC vs. PAL to match input signal properties.


ArduPilot calculates an sensor-less airspeed estimate that is used if no sensor is present or fails. ARSPD_TYPE must be set to zero in order to display this value as the airspeed item, if no sensor is present.

Callsign panel

This panel allows to display your amateur radio callsign (or any other individual character string) on your onboard OSD screen. It will read the character string from a file named “callsign.txt” placed in the root of your SD card. Mind that the default ardupilot charsets require to use capital letters for correct display. Using MAVftp is a convenient option to upload the file to your SD card without having to physically remove it from your flightcontroller.


You will find this feature in firmware 4.1 and later

User Programmable Warnings

Several user defined warnings can be set which will flash the respective osd panel item when warning level is reached or exceeded

  • OSD_W_BATVOLT - Blinks battery voltage panel if less than this value. 0-100V with up tenth volt precision

  • OSD_W_RSSI - Blinks rssi panel if less than this integet percentage value. 0-99%

  • OSD_W_NSAT - Blinks #Sat panel if less than this number. 0-30

Testing OSD with SITL

OSD functionality can be tested without autopilot- or video-hardware using a Software In The Loop (SITL) simulator setup. Follow the SITL-Instructions to setup a simulation environment. Run the simulator on current source code.

A graphical OSD simulation in a separate window can be opened by adding the following option to sim_vehicle.py:


The simulated OSD can now be set and configured via parameters.


To see all available options type:

./sim_vehicle.py -help

List of OSD Panels

Panel Name



Altitude above Home


Primary Battery Voltage


RC Received Signal Strength


Primary Battery Current


Consumed Battery Capacity


Number of GPS Satellites


Flight Mode


GCS Messages


Ground Speed


Artificial Horizon


Distance and Direction to Home


Magnetic Heading


Throttle Percentage


Compass Rose


Wind Speed and Direction


System Airspeed


Climb Rate


ESC Temperature




ESC Current


GPS Latitude


GPS Longitude


Roll degrees


Pitch degrees


Baro Temperature




Next Waypoint Distance and Direction


Cross Track Error


Total Distance Traveled


Statistics Summary


Elasped Time in Flight


Climb Efficiency




2nd Baro Temperature


Airspeed Temperature


Second Battery Voltage


Second Battery Consumption


Airspeed sensor 2


Airspeed sensor 1


Local Time of Day


Speed/Alt Sidebars


Artificial Horizon Crosshair


Distance to HOME (MSPOSD only)


Direction to HOME (MSPOSD only)


Power (MSPOSD only)


Calculated Cell Voltage for Primary Battery (MSPOSD only)


Battery Health Bar (MSPOSD only)


Arming Status (MSPOSD only)


Open Location Code


Callsign from SD card callsign.txt


2nd Battery Current


Video TX power setting


Altitude above Terrain


Calculated Cell Voltage for Primary Battery


Calculated Resting Voltage for Primary Battery


EENCE enabled status


Rangefinder Distance


Calculated Cell Resting Voltage for Primary Battery


RC Link Quality