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CFAH1602B-YYH-JPV B/L & Neg V..... again

jecottrell

New member
Just want to confirm prior to releasing a board for prototyping that what I'm attempting is correct.

On the CFAH1602B-YYH-JPV module:

Pin 16 is not implemented? (If you look at the top of the module board there is a trace leading from it, to something under the LCD module.) So, is it really connected to K or not? Data sheet says N/C. Meter says it's not also.

Pin 15 is the Vee. Vo goes to the wiper on the contrast pot and Vdd and Vee go to other connections on the pot. I've got additional pads for series resistors on each leg of the contrast pot. They will be used to make the pot most effective in adjusting the contrast. (i.e. if the contrast only gets adjusted between 5K and 7K on the 10K pot, I'll use a 2K pot and trimmer resistors on the legs.... make sense?) So the question is, where is the 'meat' of the contrast adjustment occuring in a 10K pot?

A and K for the backlight need to be added (i.e. aren't pinned out on the 1x16 SIP connection.) K can be jumped to Vss on the module, but A needs to brought off the board and current limited w/ a series resistor. Are any of the open 0805 pads on the back of the module made for doing any of this?

Thanks a bunch,

John
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CF Support

Administrator
On the CFAH1602B-YYH-JPV you can load J2 and J1 each with half of the resistor value for the current limit you would like to use for your backlight and the A and K connections to the module will be jumpered to the +5v and Gnd connections on the LCD (pins 1 and 2). By loading the resistors on the module then you don't have to worry about overdriving the backlight, and you make no connections to pins 15 and 16, or A and K at the side of the PCB, respectively.
 

jecottrell

New member
OK. I got it now.

Just another quick question to ensure I've got the correct pads picked out for J1 and J2. J1 is easy, it's the two pads just above the silkscreen 'J1'. J2 is the two pads to the right of the silkscreen 'J2', actually to the right and the one above that one (the pad to the left of the 'R2' silkscreen), no?

Thanks,

John
 
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