Help controlling a salvaged LCD from a piano keyboard

Hello everyone!
I have salvaged an LCD display from a piano keyboard and I would like to control it via an Arduino Nano.
I tried desoldering the backlight to see what kind of chip it has and there was only a black blob there with some unconnected pads.
After some searching on the internet, all I found was some chinese chips and no Arduino libraries.
I think it uses serial communication in some way. Unfortunately, I don’t have the original controller to analyze what kind of signals it sends.
The pins are: VDD, VSS, DATA, WR, CS (Those were the only pins the original controller had access to) and some unconnected pins: RD, OSCI, OSCO, IRQ, BZ, BZB
I have attached the pictures of the LCD (The wire coming out of the LCD is connected to the RD pin because I thought I had to send a clock signal through this pin).
I am a decent programmer but not experienced in Arduino/electronics so any help is appreciated!

Piano LCD Front.jpg

Piano LCD Back.jpg

MG4mes:
I tried desoldering the backlight to see what kind of chip it has and there was only a black blob there with some unconnected pads.

Rather bad idea. The markings on the five pins are all the information you will get.

MG4mes:
After some searching on the internet, all I found was some Chinese chips and no Arduino libraries.

So - what were these chips, and how do you know they are in any way related to this device?

MG4mes:
I think it uses serial communication in some way. Unfortunately, I don't have the original controller to analyse what kind of signals it sends.

It uses SPI by the look of it. But it is not obvious what is the clock. I was thinking that if you can find some SPI code for LCD displays, it is worth trying. If you can guess the initialisation code, and get it to show patterns, you are winning. :grinning:

MG4mes:
The pins are: VDD, VSS, DATA, WR, CS (Those were the only pins the original controller had access to) and some unconnected pins: RD, OSCI, OSCO, IRQ, BZ, BZB

The first thing you need to know is what was its operating voltage. This should be determined from the original device.

If you do not have the original device, you have a significant problem, but at least you have a device which includes the necessary controller. Every so often someone comes here having found a bare LCD and wondering whether an Arduino can operate it. (No! :astonished: ) It will probably be fairly safe to try it on a 5 V Arduino.

Thank you for the fast reply.

Paul__B:
So - what were these chips, and how do you know they are in any way related to this device?

I don't know if they are related, I am just guessing at this point. (Here are some of the ones I found: SC1621SS, HT1621, SW1621).

Paul__B:
It uses SPI by the look of it. But it is not obvious what is the clock. I was thinking that if you can find some SPI code for LCD displays, it is worth trying. If you can guess the initialisation code, and get it to show patterns, you are winning. :grinning:

Alright, I will try some libraries with different SPI speeds.

EDIT: Wait... is there even SPI LCD libraries? I don't seem to find one. (I did find one specific for HT1621 but that showed nothing at all)

Any help please?
Thanks