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Kosta
2001/09/25, 11:27 PM
Hey,

I recently purchased a CFAH1602B-TMC-JP, 16x2 STN Blue Negative Transmissive White Edge LED Backlit LCD Module. I also purchased a Wirz Serial back-pack to convert it to serial.
I was going through some posts so that I get an idea on how to go about putting this thing together, since I'm not too familiar with this stuff. I was trying to determine the value for the resistor needed, and came accross this thread on the forum - Thread (http://www.crystalfontz.com/forum/showthread.php?threadid=149). Here, it is stated that this particular LCD's backlight requires a supply voltage of 25mA at 3.3V. The maunal (http://www.crystalfontz.com/products/1602b-color/CFAH1602BTMCJP.pdf) for this LCD says it's 4.2V, if I'm reading it right. I was just wondering if this could be cleared up.
If it's 4.2V on my 5V source, I'm figuring I would need a 32+ ohm resistor. If it is 3.3V, I would go with the 68+ ohm resistor suggested in the thread above.

Thanks in advance,
-Kosta

CF Tech
2001/09/26, 09:40 AM
Thank you for your post. The backlight information on page 9 of the manual states the 3.3v value. You may be looking at the "Supply Voltage for LCD" value on page 5 that shows 4.2 volts--that is a different specification that does not involve the backlight.

Kosta
2001/09/27, 01:51 PM
I'm an idiot... Thanks for clearing it up, and for the quick reply...

-Kosta