Hooking up a 4x20 LCD to a Propeller

sjogan

I have dusted off an old 4x20 LDC i got from Parallax a long time ago. The only numbers on it are 2420SYNNBNZ-P.

There are 16 pins coming off the board, but only 14 are wired up to a 2X7 female header. Now I've been able to decode the pin layout ( i think) from pin 1 on the board to female header pin 1. I've downloaded from the OBEX the parallel lcd driver from Dan Miller and uploaded it to the Propeller chip.

Problems: the code assumes 16 pins, but I have 14 (on the female header). can I just ignore pins 15 and 16? (they are labeled VB+ and VB- in the code.)

Don M

Pins 15 and 16 are probably for the backlight.

HShanko

I Googled your number and that took me to http://www.parallax.com/dl/docs/prod/audiovis/DS4X20Parallel.pdf for the first item. That should detail the pin usage,

frank freedman

Don M wrote: »

Pins 15 and 16 are probably for the backlight.

InOBEX, someone may have done an object including pwm for backlight brightness.

If it is hitachi compatible you can drop to 4 data and save 4 i/o pins.....
Or add a shift register like 74xx164 and go down to three i/o pins total.

Frank

Toby Seckshund

Dr_Acula did a 4 x 20 LCD on his Dracblade.

caskaz

Hi frank.
If used counter(TC4040), LCD is connected by 2-wire to prop.
(using 8bit-mode about LCD)