3D Printed 737 MCP

@zcizek PWM modulation.. not idea what is this.This is.my first project with arduino. Sounds perfect . Yup with 120 ohms is like laser... I will investigate and try...

@Mike Tango Every Arduino has some digital output pins that are "PWM capable". In general, for Arduino MEGA that I'm using for this MCP build the PWM pins are pins 2-13.

I connected all the LEDs to the "left" Arduino in the MCP and I used pins starting with pin 13 and working my way down. That way I was able to connect all the LEDs to PWM capable pins and as mentioned I used 120 Ohm resistors between the pins and the actual LEDs.

Then, when you map your outputs in the Mobiflight interface, you simply tick a checkbox in the display tab to "Enable PWM Mode" and then in the "Compare" tab you simply eable the Interpolation Settings and enter two lines into the adjacent table to tell Mobiflight how it should manipulate the values it receives from MSFS. In this case the first line is simply 0 in both left and right column saying that if MSFS tells that the vaule is 0 (LED is OFF) then Mobiflight will also send 0 to the LED keeping it OFF. Second line then has 1 in the left column and a desired brightness value of the KD-22 LED (or any LED connected to that pin) in the range from 0 to 255 (where 255 is full bright and 0 is OFF) into the right column (In my case I'm using 12 as a value for my KD-22 LEDs).

So if you connect your physical LEDs to the above mentioned PWM capable Arduino digital output pins then you can use Mobiflight to control the brightness of those LEDs in a very simple and easy to setup way.

In mine I used 120 Ohm for both the FD ON indicator LEDs and the KD-22 LEDs as well. In hindsight I would probably recommend using higher value resistors for the KD-22 LEDs as with the 120 Ohm ones I'm using and the LEDs that are in the KD-22s that arrived in my order, those are perhaps a bit "eye-burning green laser bright". =)

Hello Pierre,

if you check the images I uploaded with the original post, then the last one (IMG_3246) shows the misaligned Arduino sitting in its orange mount ('8 Ard Mount.stl') that is fixed, using two screws each, to the grey Arduino Brace. The Arduinos are shown misaligned by about 3mm to the right compared to the holes in the back panel.

To fix that, you have to unscrew the four screws that are fixing the grey Arduino Brace to the RH and LH Braces, lift it up and then simply rotate it around the Z-Axis by 180 degrees, so the Arduinos (if the orange mounts would still be attached the way they were) would now be facing with their connectors towards you and away from the holes in the back panel wall.

As a last step you then simply need to re-attach the orange Arduino mounts, so the Arduinos will face the right way again and now they should be perfectly aligned with the holes in the back plate.

The screw holes for the mounts in the Arduino brace are shifted to one side by those 3mm and it is not easy to spot that. In my chat with Karl we agreed that it would probably be a good idea to update the Arduino Brace STL file so the print would contain an arrow that would give a hint which side should it be facing the back panel wall.

Hope it helps!

Cheers,

Zdenek

@zcizek Thank you for these clear explanation.!!

It helped a lot.

Thanks again!

Pierre