These 1602 are fun and easy to use, when I solder them to the I2C boards and only use 4 wires, and 2 of them are output pins. So I tried to explore my options and be creative and bought this interesting one, with SPI interface built in. In my haste, I confused SPI with I2C, it's a different interface. The page explained "4 wire interface". In my haste, I assumed it meant power supply and 2 data, not 4 data lines - which means 6 wires - plus more since I think the actual LED has to get power from 2 other lines (for reasons unknown).
Anyway. Here is the DISPLAY:
I do not have the experience or patience to read the 51-page manual on a ST7070. For what it's worth to me, I can just go buy another display without the onboard SPI and attach the standard I2C one that works without giving me trouble.
I'm posting here to see if anyone else has ever used these displays with onboard SPI, with a working library. The one from the adafruit site did not work (for me), and I have tried several others from a google search. I got it to power on and display some characters upside, scrolling in a unreadable manner, that I could not seem to control.