So thanks to the current world situation, I have had some time to continue trying to make this very nice display do something useful.
So, looking at the pin-out (previous post), we see that there are 3 inputs, and 1 output. I (rhetorically) wondered if there were any common interfaces that used 4 wires where the peripheral device would have 3 inputs and 1 output....
Turns out there is -- SPI:
So I connected up an Arduino Nano, and after a little trial-and-error, I came up with the following assumed pinout:
Code:
Arduino Verifone
D10 --> *SS --> 4
D11 --> MOSI --> 2
D12 <-- MISO <-- 5
D13 --> SCK --> 3
I then wrote a simple "Bit Banger" or "Fuzzer" to send random stuff to the SPI port.
Using this, with the above pinout, I do get data coming back on MISO, and things such as clearing the above pictured test mode, and in a few rare cases, I have gotten a couple random characters on the screen.
SPI has various possible clock edge triggering modes, as shown in the table below. I seem to get the most consistent data responses in SPI_MODE1.
Code:Mode CPOL CPHA Output Edge Data Capture
SPI_MODE0 0 0 Falling Rising
SPI_MODE1 0 1 Rising Falling <----
SPI_MODE2 1 0 Rising Falling
SPI_MODE3 1 1 Falling Rising
Next, I need to write another Arduino program to allow me to replay interesting sequences of data or strings.
I do want to note that this display is *far* more complex than the basic Noritake serial units. This display contains a Motorola 68000 processor, RAM, and 2 ASIC's. It is likely quite capable, but with no starting clues at all, determining the full capabilities and possible modes of this device is likely to be a very lengthy process.
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Verifone 13817 4 Line VFD (Read 1693 times)
