AirSpeed
It is an airspeed indicator. It is displayed by measuring the relative velocity with the atmosphere. It is not the ground speed.
The display unit is knot knot. One knot is 1852m per hour (1.852km / h). 100 knots is 185.2km / h.
The maximum speed required depends on the model, how to set the scale of the instrument. Of course, the required scales are different for Cessna planes and jet fighters.
Backlight
I turned on the backlight. It is illuminated by two white LEDs from the back of the scale plate. A prism sheet or a diffuser plate cut out from the disassembled liquid crystal panel is sandwiched between them, and the distance from the light source is about 1 cm. This will brighten the whole area evenly, but the white pointer will be in the shadow.Which is better, the lighting of the meter from the back side of the scale or the side surface attached to the side of the front side? I'm still at a loss.
config settings
The scales are not evenly spaced. Perhaps it is the structure of the device that measures the airspeed. In Mobiflight this can be adjusted under Modify in the ConfigWizard. A well thought out program.In Modify, I sets the Output Value to minus because the direction of rotation is reversed. It seems that it can be fixed by changing the wiring of the stepping motor, but I avoided changing the connection only for this instrument and I responded on the software side.
Didital-AirSpeed
Addition of digital display
Like the Altimeter, I have added a digital display. For the LED, I used the LED OSL30251-LYG with a 3-digit display of 0.25inch cathode common.The analog scale was also reexamined and the display was changed. The non-linear change in the scale matches the actual instrument (although some devices have a linear scale). The maximum value depends on the model, so I match it with his turboprop machine that I often use. With a maximum of 350knots, It wasn't enough to operate a jet airliner, but I came to reach it by adding a digital display.
MAX7219
I decided to add the digital display to the MAX7219 used when adding the digital display to Altimeter. Since the MAX7219 has an 8-digit display capability, it is in charge of displaying both ALT 3-digit + Speed 3-digit display. I can do it without increasing the output pin of Arduino.The Rset resistance was not changed, and it was used as it was, and there was no shortage of brightness, so it remains as it is.
config settings
The Mobiflight Module is shared with the digital altimeter. In the Display, I corrected the previous 3 digits to 8 digits, and checked to use for 1, 2 and 3 of them. FSUIPC offset is 02BCh and Indicated AirSpeed is specified. The value has been multiplied by 128, so I'm reverting it to $/128.With mobiflight 9.6, right-aligned display is no longer possible. Therefore, the Transform value is set to Round($/128,0) to round off decimals.
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