Hi, I need to use the smallest pot I can for the contrast on my 16x2 LCD(1602A). The tutorials I've seen use a 10K pot. Do I need to use a large metal pot, or can I use a little plastic one like a trimmer pot? Thanks, adown
Hi, A trimmer type will do the job.
In your final design, you do not need a pot at all.
Just connect whatever pot you have (anything from 1k to 20k will do) between Vo - pin 3 - and ground. Do not connect the other end of the pot to 5V. Adjust it for best contrast, disconnect it, measure the resistance with your multimeter and substitute the nearest standard resistor value. It will generally be between zero and 1k, likely around 470 Ohm.