Reading separate credit counts from NEO-F0

Dman325

n00b
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Jun 22, 2020
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I've been working on creating a credit display interface for my MVS-1FZ. The MVS-1FZ, as far as I can tell, does not have a pinout for the MV-LED boards. It does have the NEO-F0 chip.

Using some of the code from the MVSPlus project by Phillrb and what I could get from the Neo Geo Development wiki, I was able to tap into the data and LED clock lines on the NEO-F0 and read the data with an Arduino. My test code is checking for the LED clock 0 and LED clock 1 pins, reading all 8 data lines, and converting that into an integer. The Arduino prints out which clock pin was hit and what the data lines are set to.

What is strange is that when I view the output of the data lines from the chip, I'm seeing this:
Code:
Clock 0 is hit - Credits: 01
Clock 1 is hit - Credits: 01

Clock 0 is hit - Credits: 01
Clock 1 is hit - Credits: 01

Clock 0 is hit - Credits: 02
Clock 1 is hit - Credits: 02

Clock 0 is hit - Credits: 01
Clock 1 is hit - Credits: 01

This is from me setting dip switch #2 on, adding a coin to player 1, and adding two coins to player 2.

It looks like LEDCLK0 and LEDCLK1 are being used to control both sets of credit counts. The schematic made it look like LEDCLK0 was for the first display and LEDCLK2 was for the second display.

When I turn dip switch #2 off, I get a reading of either the total number of credits entered or 00. But it's the same situation where both clocks will report the same number (either total credits or 00).

Does anyone have an idea as to how the NEO-F0 uses the clock and data lines to send data over to the MV-LED board? Am I missing something weird with when the LEDCLK pins are activated (like one is the clock but the other is actually a latch pin)?
 
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