x275 (GI 275-style)
The x275 board's own firmware (the GI 275-style UI written in C on LVGL) running natively inside the app, fed with the simulator's values and drawn in its square bezel with the dual concentric knob. It is a complete multi-page instrument: PFD, HSI, CDI, an engine (EIS) page, EGT with Lean Assist, CHT and a fuel computer, paged by swipes or the outer knob.
- Modeled on
- Garmin GI 275-style round electronic flight instrument / EIS
- Category
- Displays
- Size
- 1 cell
- Version
- 1.0 · 2026-10-19
- Plan
- Pro
- Simulators
- MSFS 2020 · MSFS 2024 · X-Plane 11 · X-Plane 12
Variants
PFD pagev1.0
Attitude (sky / green ground, no synthetic vision), speed and altitude tapes, VS box, heading tape, cyan references, autopilot mode strip
Swipe left/right on the screen or turn the outer knob
HSI pagev1.0
Compass rose with heading bug and course needle, source label (GPS1 / VOR1 / LOC1 / VOR2 / LOC2) in its color, distance, glideslope, HDG and CRS boxes, CDI key
Page swipe / outer knob
CDI pagev1.0
Course deviation indicator with TO/FROM, CRS box and the CDI key
Page swipe / outer knob
EIS (engine) pagev1.0
POWER: manifold pressure and RPM arcs (per engine profile), bar gauges, cylinder CHT/EGT/TIT graph, ammeter, fuel quantity, battery volts; caution/warning look
Page swipe / outer knob
EGT pagev1.0
A bar per cylinder (hottest in purple, TIT as T) with Lean Assist
Page swipe / outer knob
CHT pagev1.0
A bar per cylinder on a graduated scale with the red line
Page swipe / outer knob
Fuel pagev1.0
Fuel computer: flow, used, remaining, endurance and range, and fuel/range at the active waypoint
Page swipe / outer knob
Engine profilev1.0
Which engine's gauges and limits the EIS pages draw (C172SP, C182T, TSIO-520) and the V-speed markers on the speed tape
Automatic: the aircraft profile id sent by the Hub (Ids.profile); unknown ids fall back to the C172SP
Night lightingv1.0
Bezel and knob take the red flood light with their printing backlit and the glareshield's warm light; the display keeps its colors, dimmed (Displays dimmer), and goes dark when the aircraft's avionics power is off
Panel lights: day / night / auto, and the lighting dimmers
Features
- Runs the real x275 firmware UI (the board's own firmware on LVGL 9.2) natively at ~30 fps, a 480x480 round screen
- Up to 4 independent x275s on the panel, each its own copy of the instrument
- PFD: pitch ladder, roll scale with sky pointer and slip bar, yellow aircraft symbol, magenta single-cue flight director
- PFD: airspeed tape with V-speed bands and R/G/Y/X markers from the profile, rolling-digit pointer boxes, trend and VS box with magenta VSI bar
- PFD: heading tape with TRK, GS readout, cyan speed/altitude/heading/baro references
- PFD: altitude alerter (flashes approaching the selected altitude, captured within 200 ft, amber when deviating)
- PFD: GFC 500-style autopilot mode strip (lateral, AP/YD, vertical mode with its target, armed modes)
- PFD: yellow GLIDE annunciation (Smart Glide), flashing when it comes on
- HSI / CDI: GPS in magenta, VOR/LOC in green, pilot selections in cyan; TO/FROM; on-screen CDI key cycles the source
- EIS: engine gauges per profile, digits refresh slower than pointers (as the real unit); cautions yellow, warnings in a flashing red box until acknowledged
- EGT: Lean Assist marks each cylinder's peak, announces the first (and last) to peak with the difference from peak, LEAN TO PEAK
- Fuel: remaining set by the pilot (FUEL EST) or from the tank gauges, then integrated from fuel flow; endurance and range, red when the waypoint can't be reached
- Data entry keypad (3x3, +/-, backspace, Back / Enter) for baro, heading, altitude, speed and fuel; values sent as steps
- Smoothed values between Hub updates; WAITING FOR DATA and NO SIM DATA banners when the stream stops
- Page dots appear briefly after each page change
Your aircraft: The Hub's profile id picks the firmware's engine profile (c172sp, c182t, tsio520; others fall back to c172sp): EIS gauges and limits, cylinder count / TIT, and V-speed markers on the speed tape.
On the iPad
- Swipe left / right on the display to change page (the swipe belongs to the instrument, not the app's pages)
- Drag around the outer ring of the dual knob to change page; drag the inner knob to step the selected field (baro, heading, altitude, speed, course); fast turns step x5 for heading, altitude and course
- Tap (push) the knob to move to the next field on the page; hold (long push) to sync it: baro standard, heading sync, altitude sync, speed sync, course sync
- On the EIS page a push acknowledges a flashing warning; on the EGT page it toggles Lean Assist; on the Fuel page it opens the fuel estimate
- Tap a reference box on the PFD (speed, altitude, heading, baro) to open the keypad for it
- Tap the CDI key on the HSI / CDI pages to cycle the navigation source
- Tap FUEL EST on the Fuel page to enter fuel remaining
Settings
- None of its own in the app: page and the knob's field are in the instrument; the engine profile follows the aircraft; panel lighting applies
Keys and controllers
Map any of these to a key, a game controller's button or axis, or a MIDI knob (how):
- COM 1 MHz +
- COM 1 MHz -
- COM 1 channel +
- COM 1 channel -
- COM 1 swap
- NAV 1 MHz +
- NAV 1 MHz -
- NAV 1 channel +
- NAV 1 channel -
- NAV 1 swap
- CDI: next source
- Course +
- Course -
- Course sync
- Heading bug +
- Heading bug -
- Heading bug sync
- Altitude +
- Altitude -
- Altitude sync
- Baro +
- Baro -
- Baro sync
Simulator data
What the Hub reads from the simulator for this instrument, and what the instrument sends back. Names are the simulators' own: MSFS SimVars and events, X-Plane datarefs and commands.
Reads
| Value | MSFS | X-Plane |
|---|---|---|
| Pitch attitude, + nose up (deg) | ATTITUDE INDICATOR PITCH DEGREES (degrees) | sim/flightmodel/position/theta |
| Bank angle, + right wing down (deg) | ATTITUDE INDICATOR BANK DEGREES (degrees) | sim/flightmodel/position/phi |
| Slip/skid ball position, -1..1 | TURN COORDINATOR BALL (position) | sim/cockpit2/gauges/indicators/slip_deg |
| Indicated airspeed (kt) | AIRSPEED INDICATED (knots) | sim/cockpit2/gauges/indicators/airspeed_kts_pilot |
| True airspeed (kt) | AIRSPEED TRUE (knots) | sim/flightmodel/position/true_airspeed |
| Ground speed (kt) | GPS GROUND SPEED (knots) | sim/flightmodel/position/groundspeed |
| Indicated altitude (ft) | INDICATED ALTITUDE (feet) | sim/cockpit2/gauges/indicators/altitude_ft_pilot |
| Vertical speed (fpm) | VERTICAL SPEED (feet per minute) | sim/cockpit2/gauges/indicators/vvi_fpm_pilot |
| Altimeter setting (inHg) | KOHLSMAN SETTING HG (inHg) | sim/cockpit2/gauges/actuators/barometer_setting_in_hg_pilot |
| Heading (glass AHRS heading, else magnetic heading) (deg magnetic) | HEADING INDICATOR (degrees) | sim/cockpit2/gauges/indicators/heading_AHARS_deg_mag_pilotsim/flightmodel/position/mag_psi |
| Ground track (deg magnetic) | GPS GROUND MAGNETIC TRACK (degrees) | sim/cockpit2/gauges/indicators/ground_track_mag_pilot |
| Heading bug (deg) | AUTOPILOT HEADING LOCK DIR (degrees) | sim/cockpit2/autopilot/heading_dial_deg_mag_pilot |
| Selected altitude (ft) | AUTOPILOT ALTITUDE LOCK VAR (feet) | sim/cockpit2/autopilot/altitude_dial_ft |
| Selected airspeed (kt) | AUTOPILOT AIRSPEED HOLD VAR (knots) | sim/cockpit2/autopilot/airspeed_dial_kts_mach |
| CDI/HSI navigation source: 0 GPS, 1 NAV (enum) | GPS DRIVES NAV1 (bool) | sim/cockpit2/radios/actuators/HSI_source_select_pilot |
| The NAV source is a localizer (1/0) (bool) | NAV HAS LOCALIZER:1 (bool)GPS DRIVES NAV1 (bool) | sim/cockpit2/radios/actuators/nav1_frequency_hzsim/cockpit2/radios/actuators/HSI_source_select_pilot |
| CDI needle valid (1/0) (bool) | HSI CDI NEEDLE VALID (bool) | sim/cockpit2/radios/indicators/hsi_flag_from_to_pilot |
| Course shown on the HSI (deg) | GPS WP DESIRED TRACK (degrees)NAV OBS:1 (degrees)GPS DRIVES NAV1 (bool) | sim/cockpit2/radios/actuators/hsi_obs_deg_mag_pilot |
| Course deviation, + = course to the right (dots (-2.5..2.5)) | HSI CDI NEEDLE (number) | sim/cockpit2/radios/indicators/hsi_hdef_dots_pilot |
| TO/FROM flag: 0 off, 1 TO, 2 FROM (enum) | HSI TF FLAGS (enum) | sim/cockpit2/radios/indicators/hsi_flag_from_to_pilot |
| Glideslope valid (1/0) (bool) | HSI GSI NEEDLE VALID (bool) | sim/cockpit2/radios/indicators/hsi_flag_glideslope_pilot |
| Glideslope deviation (dots) | HSI GSI NEEDLE (number) | sim/cockpit2/radios/indicators/hsi_vdef_dots_pilot |
| Distance to the station / waypoint (HSI) (nm) | HSI DISTANCE (nautical miles) | sim/cockpit2/radios/indicators/hsi_dme_distance_nm_pilot |
| Flight director on (1/0) (bool) | AUTOPILOT FLIGHT DIRECTOR ACTIVE (bool) | sim/cockpit2/autopilot/flight_director_mode |
| Flight director pitch command (deg) | AUTOPILOT FLIGHT DIRECTOR PITCH (degrees) | sim/cockpit2/autopilot/flight_director_pitch_deg |
| Flight director bank command (deg) | AUTOPILOT FLIGHT DIRECTOR BANK (degrees) | sim/cockpit2/autopilot/flight_director_roll_deg |
| Turn rate, + right (turn coordinator) (deg/s) | TURN INDICATOR RATE (degrees per second) | sim/flightmodel/position/Qsim/flightmodel/position/Rsim/flightmodel/position/phisim/flightmodel/position/thetasim/cockpit2/gauges/indicators/turn_rate_heading_deg_pilot |
| Manifold pressure, engine 1 (inHg) | RECIP ENG MANIFOLD PRESSURE:1 (inHg) | sim/cockpit2/engine/indicators/MPR_in_hg[0] |
| Engine RPM, engine 1 (rpm) | GENERAL ENG RPM:1 (rpm) | sim/cockpit2/engine/indicators/engine_speed_rpm[0] |
| Oil pressure, engine 1 (psi) | GENERAL ENG OIL PRESSURE:1 (psi) | sim/cockpit2/engine/indicators/oil_pressure_psi[0] |
| Oil temperature, engine 1 (degF) | GENERAL ENG OIL TEMPERATURE:1 (fahrenheit) | sim/cockpit2/engine/indicators/oil_temperature_deg_C[0]sim/aircraft/engine/acf_max_OILT |
| Fuel pressure, engine 1 (psi) | GENERAL ENG FUEL PRESSURE:1 (psi) | sim/cockpit2/engine/indicators/fuel_pressure_psi[0] |
| Fuel flow, engine 1 (gal/h) | ENG FUEL FLOW GPH:1 (gallons per hour) | sim/cockpit2/engine/indicators/fuel_flow_kg_sec[0] |
| Vacuum / suction (inHg) | SUCTION PRESSURE (inHg) | sim/cockpit/misc/vacuum |
| Left main tank quantity (gal) | FUEL TANK LEFT MAIN QUANTITY (gallons) | sim/cockpit2/fuel/fuel_quantity[0] |
| Right main tank quantity (gal) | FUEL TANK RIGHT MAIN QUANTITY (gallons) | sim/cockpit2/fuel/fuel_quantity[1] |
| Ammeter, + charging (A) | ELECTRICAL BATTERY LOAD:1 (amperes) | sim/cockpit2/electrical/battery_amps[0] |
| Main bus voltage (V) | ELECTRICAL MAIN BUS VOLTAGE (volts) | sim/cockpit2/electrical/bus_volts[0] |
| Cylinder head temperature, engine 1 (degF) | RECIP ENG CYLINDER HEAD TEMPERATURE:1 (fahrenheit) | sim/cockpit2/engine/indicators/CHT_deg_C[0]sim/aircraft/engine/acf_max_CHT |
| Exhaust gas temperature, engine 1 (degF) | GENERAL ENG EXHAUST GAS TEMPERATURE:1 (fahrenheit) | sim/cockpit2/engine/indicators/EGT_deg_C[0]sim/aircraft/engine/acf_max_EGT |
| Instrument page to show (start page) (enum) | From the Hub | From the Hub |
| Display brightness (setting) | From the Hub | From the Hub |
| Heartbeat counter (count) | From the Hub | From the Hub |
| Autopilot modes, one bit each (ApBit: ap, fd, yd, hdg, nav, apr, bc, alt, vs, flc, lvl, gs, vnv) (bitfield) | AUTOPILOT MASTER (bool)AUTOPILOT FLIGHT DIRECTOR ACTIVE (bool)AUTOPILOT YAW DAMPER (bool)AUTOPILOT HEADING LOCK (bool)AUTOPILOT NAV1 LOCK (bool)AUTOPILOT APPROACH HOLD (bool)AUTOPILOT BACKCOURSE HOLD (bool)AUTOPILOT ALTITUDE LOCK (bool)AUTOPILOT VERTICAL HOLD (bool)AUTOPILOT FLIGHT LEVEL CHANGE (bool)AUTOPILOT WING LEVELER (bool)AUTOPILOT GLIDESLOPE HOLD (bool) | sim/cockpit2/autopilot/servos_onsim/cockpit2/autopilot/flight_director_modesim/cockpit2/switches/yaw_damper_onsim/cockpit2/autopilot/heading_statussim/cockpit2/autopilot/nav_statussim/cockpit2/autopilot/approach_statussim/cockpit2/autopilot/backcourse_statussim/cockpit2/autopilot/altitude_hold_statussim/cockpit2/autopilot/vvi_statussim/cockpit2/autopilot/speed_statussim/cockpit2/autopilot/roll_statussim/cockpit2/autopilot/glideslope_status |
| Autopilot vertical speed target (fpm) | AUTOPILOT VERTICAL HOLD VAR (feet per minute) | sim/cockpit2/autopilot/vvi_dial_fpm |
| Text: active (next) waypoint ident (text) | GPS WP NEXT ID (string8) | Not available |
| Text: engine/aircraft profile name (text) | From the Hub | From the Hub |
Sends
| When you… | MSFS | X-Plane |
|---|---|---|
| Inner knob on the baro field, or a baro entered on the keypad (as steps) | KOHLSMAN_SET | sim/cockpit2/gauges/actuators/barometer_setting_in_hg_pilot |
| Long push on the baro field | KOHLSMAN_SET | sim/cockpit2/gauges/actuators/barometer_setting_in_hg_pilot |
| Inner knob on the heading field, or a heading entered on the keypad | HEADING_BUG_SET | sim/cockpit2/autopilot/heading_dial_deg_mag_pilot |
| Long push on the heading field | HEADING_GYRO_SETHEADING_BUG_SET | sim/instruments/DG_sync_magsim/cockpit2/autopilot/heading_dial_deg_mag_pilot |
| Inner knob on the altitude field, or an altitude entered on the keypad | AP_ALT_VAR_SET_ENGLISH | sim/cockpit2/autopilot/altitude_dial_ft |
| Long push on the altitude field | AP_ALT_VAR_SET_ENGLISH | sim/cockpit2/autopilot/altitude_dial_ft |
| Inner knob on the speed field, or a speed entered on the keypad | AP_SPD_VAR_SET | sim/cockpit2/autopilot/airspeed_dial_kts_mach |
| Long push on the speed field | AP_SPD_VAR_SET | sim/cockpit2/autopilot/airspeed_dial_kts_mach |
| Inner knob on the course field (HSI / CDI pages) | VOR1_SET | sim/cockpit2/radios/actuators/nav1_obs_deg_mag_pilotsim/cockpit2/radios/actuators/hsi_obs_deg_mag_pilot (also, when HSI_source_select_pilot == 0) |
| Long push on the course field | VOR1_SET | sim/cockpit2/radios/actuators/nav1_obs_deg_mag_pilotsim/cockpit2/radios/actuators/hsi_obs_deg_mag_pilot (when HSI shows NAV1) |
| CDI key on the HSI / CDI pages | TOGGLE_GPS_DRIVES_NAV1 | sim/cockpit2/radios/actuators/HSI_source_select_pilot (2 GPS <-> 0 NAV1) |
Add-on aircraft with their own systems may use other variables; the Hub reads the standard ones.
Changes
The instrument's version counts what its faces share (the case, the mechanism, the data, the sounds); a face's own version counts that face alone.
- 1.0 2026-10-19
- First numbered version.
