Tuesday, December 5, 2006

Mac OS X USB LCD Info

Since I haven't had any LCD Kits available for a while, I thought I would clear up some details about the kit for people who want to try it on their own.

The LCD is a HD44780 compatible character LCD. It is connected to the Mac USB port using a Belkin F5U002 USB Parallel adapter. Make sure to get the correct version that uses a separate USB cable.

The pinout I used for the kit and the Mac OS X USB LCD Command Line Tool is available here: Beyond Logic Interfacing Example. With some minor changes to get power from the parallel port, the final pinout is:

Centronics
Parallel    LCD
30             1
13,14          2
30             3
36             4
29             5
1              6
2              7
3              8
4              9
5             10
6             11 
7             12
8             13
9             14

Following this pinout should allow you to use the Mac OS X USB LCD Command Line Tool on your own cable and LCD.

2 comments:

miles said...

I followed your instructions for the pinout but I have a problem, the lcd is not backlight or at least it is very dim.

Instead of using an lcd adapter cable like you had included in your kit, I soldered everything to the parallel usb board; including the usb wires. It worked, I see the text that I type in the program on the lcd but the backlight is very dim. Is there anything that you can think of that I might have done wrong that would have resulted in this?

epooch said...

What is dim? The back light or the text?. The instructions I posted do not include a connection for a backlight. You can use the instructions here:

http://lcdproc.sourceforge.net/docs/stable-0-5-x-user.html#hd44780-connections-backlight.circuit

to add a backlight using the 5 volts from the USB connector.