I found an old LCD in my pile of trunk. I would like to be able to use it. However, someone (possibly / probably me) sawed off the part of the PCB with the series code, so I can't know what the controller chip is. I'm trying to figure it out.
My analysis so far:
The display has backlight. There are 16 pins, so HD44780 would be my first guess (3 power pins, 11 data pins and 2 for backlight). The three pins that are wired up could be power, looking at the traces, and the last two LED anode and cathode. So I tried to wire it up with pin 1 to 0V, pin 2 to 5V, and pin 3 (probably contrast) to 0V. I got this result:
This looks like HD44780 to me, with a 2x16 screen.
But I've got a few questions about this:
- Are there other (not HD44780-compatible) displays that would give this display when only power is supplied (but no controls), or is this specific for HD44780?
The pinout I have used up to now for all LCDs with HD44780 I've used so far (as far as I can remember) had a pinout like this:
- Power (Vss, Vdd, Vcontrast)
- Control (RS (register select, command or data), R/W (read / not write), E (enable)
- Data (DB0 - DB7)
- Possibly backlight (Anode, Cathode)
But is this a standard? Can I assume that this uses the same pins for the same functions? And, if not, is it safe to just try it, or could things go wrong? If it could go wrong, is there a way to say judging by the PCB traces what lines would be data, probably?
I don't think it's important, but in the end I intend to use this chip with a PIC. I have used HD44780 displays with PIC before, so I have working code to try out (and also other displays with HD44780 (or ~compatible) to check the code and setup).