HI all. First off sorry if I'm posting in the wrong forum section. I wasn't really sure which would be best, if this isn't the correct one please move my topic.
I'm working on a small project where I am using the arduino's analog read to read the voltage from a potentiometer. I have taken this voltage and mapped it to values between 0-25 for letters to be displayed on an LCD screen. It works pretty well the only problem I'm having is that when turning the potentiometer it tends to be too sensitive and the letters change to easily requiring very precise touch.
My question is how can this be fixed so it will move more smoothly/less sensitive through the letters? The only thing I can currently think of is that maybe the arduino doesn't have a high enough resolution to switch between 25 values? Otherwise maybe there is a different type of potentiometer I should be using?
Thanks for taking a look. If you need me to post code I can do that too.
It's a 10-bit ADC, so the resolution is 1024 (0-1023) and that should be plenty and it should be no problem scaling-down to just 25 values.
With pot rotation of about 270 degrees converted to 25 counts, that's about 10 degrees of rotation for a one-count change. You should be able to get the count you want, but it's going to be somewhat "touchy".
You might try a capacitor between the analog input and ground. Or you might consider a 10-turn pot, or a rotary encoder.
Does it read about 12 at mid position as expected? If you have a logarithmic pot all of the "change" will be concentrated at one end and that could be an issue.
It is a linear potentiometer. I think what DVDdoug was saying about have a potentiometer with more than one turn is what should solve the problem on the touchiness. If I remember I'll post back on the results when I get my hands on a 5 or 10 turn pot.