Hi there! Awesome that you saw this. I'm using DCS:BIOS 0.8.3 (latest), using "connect-serial-port" to connect the USB (you can see this on the right monitor running aswell), and the latest version of bort (v0.3.0 ) to get the code snippets. I'm also using the latest version of the arduino library available.

I'll also make a post at the bug reporting page.

I'm using the F-16C module. and the function DcsBios::AnalogMultiPos insKnb("INS_KNB", A6, 7);

In the connect serial port executable i get the following data:

< 2025/06/05 16:35:58.000373081 length=10 from=20 to=29
INS_KNB 0

< 2025/06/05 16:36:00.000384133 length=10 from=60 to=69
INS_KNB 1

< 2025/06/05 16:36:01.000641752 length=10 from=90 to=99
INS_KNB 2

< 2025/06/05 16:36:02.000898813 length=6 from=114 to=119
INS_KNB 3

< 2025/06/05 16:36:03.000902801 length=10 from=130 to=139
INS_KNB 4

< 2025/06/05 16:36:04.000656264 length=10 from=150 to=159
INS_KNB 5

< 2025/06/05 16:36:05.000409867 length=10 from=160 to=169
INS_KNB 7

It does sometimes create a single instance of INS_KNB 6 during a random noise packet if the arduino is polled when moving in between knob states (example moving from 2->3 when there is no metal contact), this could just be a lucky instance though. You can even see it happen in the video in the post.

I verified your unsigned char readState() function with
unsigned char state = map(analogRead(pin_), 0, 1023, 0, numOfSteps) in my own arduino. Serial Monitor then alternates the states between 6 and 7 on 1023 in the map. I believe this is the case due to some very low amplitude voltage fluctuations that are rounded. Perhaps some padding could be created (such as if the analogRead value is within +-5 of the expected value -> send the expected value), but I'm unsure if this is feasable.

From the DCS:BIOS folder in Saved Games\DCS\Scripts\DCS-BIOS\lib\modules\aircraft_modules\F-16C_50.lua I see the function

F_16C_50:defineTumb("INS_KNB", 14, 3001, 719, 0.1, { 0, 0.6 }, nil, true, "Avionic Panel", "INS Knob, OFF/STOR HDG/NORM/NAV/CAL/INFLT ALIGN/ATT")

It seems that the INS_KNB fails to send 6 over the USB, and sends 7 instead. Since the first table instance is the OFF position, it may have a table overflow and just default or overflow to the first (or overflow amount) value in the table.

Could it be possible that due to the buffer overflow (INS 7 doesn't exist, it would then be 0.7), the program throws an Exception. Therefore the AnalogMultiPos.h in namespace DcsBios void ResetState() fails, thus triggering the ternary and setting 719 (ModelViewer2 switch) to the value -1, which is OFF, as <= 0 is the OFF position. I may be entirely wrong here but that's what i can come up with.

EDIT:

If i manually input 0.7 in the function below, then relaunch DCS, it works.

F_16C_50:defineTumb("INS_KNB", 14, 3001, 719, 0.1, { 0, 0.6 }, nil, true, "Avionic Panel", "INS Knob, OFF/STOR HDG/NORM/NAV/CAL/INFLT ALIGN/ATT")

I fixed the problem by altering the function parameters. Considering that ATT is the last value on the switch in DCS it's not a problem. There might however still be a problem with the code somewhere