[Torslund]

Sorry if drifted away. If I understood correct that rmp2 input is designed for low Hz and that why an other capacitor. Running rpm1 input from spark is also low HZ. Max hundreds Hz. If input is x36 or x60 wheel frequency is also higher. Option, different capacitors for tooth wheel and distributor setups, or rpm2 as distributor input.

[PSIG]

If I understood correct that rmp2 input is designed for low Hz and that why an other capacitor. [examples]

Correct. Capacitors involve time. That time can work for you or against you, or both.

Option, different capacitors for tooth wheel and distributor setups, or rpm2 as distributor input.

Possibly, depending on the factors you stated, but also knowing if there is an issue and exactly what it is, and that the issue cannot be solved more efficiently or effectively a different way and without excessive secondary or negative side-effects.

The capacitor values are generic, in an attempt to thwart an unknown level of noise or signal distortion, on as many of the hundreds of different setups out there as possible. One size does not fit all, but not all issues should be addressed with signal capacitors either, e.g., if you have a noisy signal, fix the noise source instead of applying a workaround "band-aid" like capacitors or shielding — whenever possible.

You can test different capacitance by simply holding or soldering another cap "piggyback" on the original, or by switching the RPM1/VR1+ and RPM2/VR2+ inputs in code. etc. Don't forget there is also software filtering available, but that has its own set of side-effects. Back to finding the problem source.

I responded here as your question loosely relates to some perceived decoder issues. Back to decoders!

[ThomasColtart]

I have 2 Crank triggers: 138 count no missing teeth, and other one is a single tooth at TDC. It is a 6 cylinder(1986 bmw 325). I found a decoder that was discussed about a very similar setup but there were 135 teeth instead of 138(I think it was Audi). I know many older Bosch motronic systems have this setup (Audi, Porsche, bmw) with various number of teeth because it’s reading the ring gear on the flywheel. Could I propose some sort of generic decoder that could be set up for these? I think the main problem is that the number is not evenly divisible with 360 but it seems like a simple equation to get them to work. Like in my situation(and many of these older setups), i am using a distributor so I would only need the ecu to count every 46 teeth and then use that signal for spark, and reset every time the single pin comes around. Could this somehow work with the current firmware or could you write a decoder for it? Thank you very much.

[theonewithin]

seems like a simple equation to get them to work.

Giggles to self....

If it were simple then it would already be part of the firmware...

It is NOT simple.

Put up a bounty if you want it done else hope someone who has the same wheel and has the required expertise to write the decoder does it.

Else change it out for something supported.

[PervertAngelMarc]

seems like a simple equation to get them to work.

Giggles to self....

If it were simple then it would already be part of the firmware...

It is NOT simple.

because that's how it works... a lot of simple stuff adds up to not being reasonable to add everything

[ThomasColtart]

Ok maybe I shouldn’t have said “simple”. Sorry about that. I’d like to request this decoder:

2-crank triggers
138 tooth no missing teeth
1 tooth

For use with a distributor based 6 cylinder.

I don’t know how to do a bounty but I’m more than willing to donate for having this added. Please consider. Thank you.

[PervertAngelMarc]

Ok maybe I shouldn’t have said “simple”. Sorry about that. I’d like to request this decoder:

2-crank triggers
138 tooth no missing teeth
1 tooth

For use with a distributor based 6 cylinder.

I don’t know how to do a bounty but I’m more than willing to donate for having this added. Please consider. Thank you.

The triggers don't really need to be cylinder count specific. Just FYI, sounds like you want what the software refers to as "dual wheel", just to make communication/and navigation of software more intuitive later.

[ThomasColtart]

Ooh. I just found this. Maybe my setup is already supported.
https://wiki.speeduino.com/en/decoders/Non-360

[Chris Wolfson]

Maybe, before you spent your money on a 333 tooth decoder, ask how fast Speeduino can count.

At some RPM it might just quit, because it is not enough time for the CPU to separate two signals?

[PervertAngelMarc]

Maybe, before you spent your money on a 333 tooth decoder, ask how fast Speeduino can count.

At some RPM it might just quit, because it is not enough time for the CPU to separate two signals?

??? The signals go in separated. IDK about Speeduino, but I remember the Microsquirt manual states that 360 tooth wheels aren't supported because of (I think they said firmware but) computational/speed limitations of the controer. Dop bear can PROBABLY support 360 and beyond; don't quote me on that.