Controlling 7-Segment display brightness
7-segment displays can have their brightness set using the value of an output configuration. This is most often used to turn the displays off and on based on whether the avionics have power, or to adjust the brightness based on the aircraft’s panel backlight level.
Note
This guide assumes an output configuration is already created to display a value on the display.
Turning the display on and off
The following steps demonstrate how to use an airplane’s avionics power state in a Cessna 172 (G1000) to turn a MAX7219 display module off and on with Microsoft Flight Simulator 2020 and Microsoft Flight Simulator 2024.
Create an output configuration for the brightness
Add an output configuration named Display brightness. Select the CIRCUIT GENERAL PANEL ON preset.
This preset is 0 when the avionics do not have power and 1 when they do.
Tip
The variable for avionics power may be different in other aircraft.
Add a transform modifier to avionics power output
On the Modify tab for the output created in the previous step, add a Transform modifier and set the value to $*5. This multiplies the value from the simulator (either 0 or 1) by five to provide a brightness value of 5 when the avionics have power.
Tip
7-segment displays support 1–15 for brightness values. Adjust the brightness of the display when on by changing 5 to the desired brightness level. See the following section to use a dynamic brightness level.
Use the avionics power output to control the display brightness
On the Display tab for the 7-segment display output configuration, set the Brightness ref. dropdown to the output configuration added in the first step.
Adjusting the brightness display based on the avionics brightness
The following steps demonstrate how to use an airplane’s avionics power state and avionics brightness value in a Cessna 172 (G1000) to control the brightness of a MAX7219 display with Microsoft Flight Simulator 2020 and Microsoft Flight Simulator 2024.
Create an output configuration for the avionics power
Add an output configuration named Avionics power. Select the CIRCUIT GENERAL PANEL ON preset.
This preset is 0 when the avionics do not have power and 1 when they do.
Tip
The variable for avionics power may be different in other aircraft.
Create an output configuration for the brightness
Add an output configuration named Display brightness. Select the AVIONICS BRIGHTNESS preset.
Tip
The variable for avionics brightness may be different in other aircraft.
Add a config reference for the avionics power
On the Modify tab for the Display brightness configuration, add a reference to the Avionics power output configuration.
Adjust the brightness value range
The brightness value from the simulator ranges between 0–100, however the 7-segment display requires a value between 0–15.
To adjust the range, on the Modify tab for the Display brightness configuration, add an Interpolate modifier. Set the input values to 0 and 100. Set the output values to 0 and 15.
Ensure the brightness is 0 when the power is off
When the aircraft is cold and dark, the brightness sim variable may still report the actual position of the knob instead of 0.
To address this, on the Modify tab for the Display brightness configuration, add a Transform modifier to multiply the brightness by the avionics power value config reference using the formula $#. This ensures the output brightness will be 0 when the avionics power reports 0.
Use the brightness output to control the display brightness
On the Display tab for the 7-segment display output configuration, set the Brightness ref. dropdown to the Display brightness output configuration.