LCD contrast is very low


New member
Hi, I bought a 2x16 character lcd CFAH1602ARGHJP and it's working nicely, however I think it's not as brigt as I expected, I mean when backlight is ON text almost disapears. I've tried with several combinations of Vcontrast/Vled to get the best, but the results are poor. My LCD doesn't look like that of the webpage, so can anyone can tell me the combination of voltages/resistors to get the best performance?? Thanks in advance =)
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You should get adequate contrast with the Vo set to about 1 volt. The lower that Vo is, the higher the contrast. So, try grounding Vo and see if that increases the contrast. For even more range, Vo can go negative a few volts, but typically that is not necessary.


New member

I tried negative voltages for Vo but that not works. What I did and now it's working better is

1. Vo=1.6 v
2. Iled=130mA (4.2v)

I'm not satisfied at all, I expected more, but for now that's enough for my purposes. Thanks buddy =)