AXE133 serial LCD driver - Non-standard pinout ! WHY ?

Hi everybody,

I was wondering why the 16-pin output connector of this Picaxe Board did not conform to the pinout of a standard LCD !? (1-2-3 ... 14-15-16)

It is realized to the standards of some strange OLED-2 Lines (15-16-1-2 ... 12-13-14) and is therefore not adapted to conventional LCD displays.

Too bad, especially since this board is designed to place a switching transistor backlight (for LCD display ! ) ... but the pins do not line up!

zorgloub said:

Hi everybody,

I was wondering why the 16-pin output connector of this Picaxe Board did not conform to the pinout of a standard LCD !? (1-2-3 ... 14-15-16)

It is realized to the standards of some strange OLED-2 Lines (15-16-1-2 ... 12-13-14) and is therefore not adapted to conventional LCD displays.

Too bad, especially since this board is designed to place a switching transistor backlight (for LCD display ! ) ... but the pins do not line up!

Click to expand...

I think you chose an LCD with the wrong standard .

In my part of the world, type 'A' is the most common and are often the cheapest. Rev-Ed has chosen to support this standard. Type 'B' is the second most popular, with type 'C' (like yours) being the least common.

I understand your frustration but we live in a world of registered designs, copyrights and lawyers. Lawyers have a habit of working for one manufacturer and making money by suing other manufacturers for breach of the these designs and copyrights (my apologies to any lawyers reading this - it is my attempt at humour). So the world ends up with many different designs and 'standards'. Like the pin-outs of many identically-performing devices like transistors and voltage regulators - frustrating.

In your case, with the LCD pins, it would be possible to cut a 2-pin section of header strip for the LCD end pins 15, 16 and connect then by two short wires to the AXE133 host connector.

Peter

FWIW I salvaged some 2x24 LCDs from Rolm phones and they had connections that were offset from the expected logical sequence- Always check! Non standard might be standard... ;-0

Bottom line is we designed the AXE133 board to match the LCD and OLED modules which we stock and sell. The AXE133 should work with other LCD and OLED pin-outs but might require wire jumper connections and may involve some wire crossover.

Hi, Peter & Cie

Indeed, there are several standards for LCD displays, but, if I am not mistaken, my model used here is indeed the most "Standard A" according to the link you have indicated!
---> Vss(1), Vdd, V0, RS, R/W, Enable, D0 to D7, A, K(16)

So, finally, I realized my interface "standard", double-sided, with a 20X2 with a configuration entry by jumper (selection of character number or number of lines), integrated backlight, ...
And the program, which is in the process of being realized, will also be able to create its own graphic characters by the master MCU (and modify them if necessary during system operation).
My interface thus recognizes an additional "command" for the creation of graphic characters.

zorgloub said:

Indeed, there are several standards for LCD displays, but, if I am not mistaken, my model used here is indeed the most "Standard A" according to the link you have indicated!
---> Vss(1), Vdd, V0, RS, R/W, Enable, D0 to D7, A, K(16)

Click to expand...

The model in your picture in the first post is not standard A. The pins are in the bottom left corner on standard A. Yours, when the correct way up, will have the pins in the top left corner.

It does not seem to me that the corner to be considered is the most important.
What to check is the successive order of the contacts: vss (1) ... A (15), K (16). (see post #5)
Correct?

The top-left or bottom-right corner LCDs may be similar hardware with different (internal) pixel display firmware. Altronics also supply these (20x4), with a bottom-right pin connector. I haven't checked the pin functions/numbering.

Your wiring drawing in post #5 is probably your best solution to the current problem.