Hacking VFD display Key Scanner with an Arduino

Discussion in 'Embedded Systems and Microcontrollers' started by samf48, Nov 10, 2015.

  1. samf48

    Thread Starter New Member

    Nov 5, 2015
    Hello all, I'm wondering if anyone can help me figure out how to talk to a Sanyo 75700 key scanner IC. The key scanner uses Sanyo's CCB protocol as outlined in the data sheet with a Chip Enable, Data In, Data Out, and Clock line. The chip interfaces with a Renesas M30873MHA microcontroller. My ultimate goal is to use an Arduino (or whatever works) to mimic the output of the key-scanner and send it to the microcontroller. The key scanner is hooked up to the button contacts on the faceplate of the radio. So as far as I can tell, when a button is pressed, for example the FM/AM button, the microcontroller reads the DO line of the key scanner and the mode or changes. Of course that is only speculation because I have yet to figure out how to read this line.

    There is a CCB library for the Arduino which I've loaded up. I hooked up just the faceplate and powered up the chip through the same connector that normally connects the faceplate to the radio (see pic). After that I tried running the Arduino to read the DO line while pressing different buttons on the faceplate but it seems like it's not reading anything out. The DO line does have a 10k Ohm pullup resistor but that is also powered up via the 5V line.

    Any ideas?