[Success Story] 99 miata 1.8 turbo PnP setup #53

[AndreyB]

registration is on the slack forum thread which was mentioned above

[scramblr]

By the way, my knowledge of all the functions of the discovery board is very limited. I've only made it as far as I have by trial and error and using subtle clues in schematic drawings.

[AndreyB]

I do not follow why discovery is being mentioned? it is believed that all 12 low side drivers on Frankenso are using good to use Discovery pins.

[scramblr]

I guess that goes to show my lack of understanding of the board
My brain works better with mechanical things
I'll try not confusing matters more.
I can say that I'm confident in the circuit for the solenoid.
One wire to 12v, the other to w37.

[AndreyB]

this is a forum and we are chatting. three messages every 24 hours is my limit. See you on slack

[scramblr]

Question about AC. I recently updated to the most recent bundle for Frankenso in my NB miata, and wanted to try out the AC functionality. I've connected my AC relay to a low side driver and am able to actuate the relay successfully with the bench test button, but am struggling with the AC switch input. I currently have the input on Pin PA6, but I'm having trouble getting it to reliably detect the signal. TunerStudio will sometimes show "AC Switch On" on the bottom of the gauge panel, but only if the engine is not running. This is only the case when I have the AC switch mode set to "Pullup." Any pointers on what pin I should be using? Do I need to add/remove resistors to make this work?

[stefanst]

It looks like what you did should work. PA6 is for Input_10 which has an external 10k pullup. You should not need to have to set the input pin to pullup as well- that doesn't make sense on an analog input.
Can you verify that the voltage level on PA6 on the brain board actually changes? With the switch off it should be 3.3V and with it on it should be around 3.3V.

[BeerMoneyMotorsports]

We had this issue on the Hellen64 for miata. The miata has a diode in the circuit which screws up the ability to use PA6. Can you switch to PB0? Should be pin 36(AV8) on the connector. This is what is used on the Hellen now and works great.

[scramblr]

From my interpretation of the Frankenso schematic, pin 36 connects to PD7 on the brain board, whereas PB0 doesn't go to any of the pins on the connector. I put a snip of the schematic I'm referencing. Am I seeing this right?

image.png (175.78 KiB) Viewed 5839 times

[BeerMoneyMotorsports]

Unfortunately i am unfamiliar with the schematics on the Frankenso. I was thinking in terms of MRE, my apologies.