- Thu Nov 06, 2014 5:11 pm
#176652
So I've always put small 100nF caps on AVCC and AREF when I need to do analog to digital conversions on my atmel chips. Everything worked, but I just got an LCD working and I'm getting a ~15% error between what my meter and the A2D are claiming the voltage is. If I remove the cap on either AVCC or AREF (ie hardware the connection) the error goes away.
So, should I only be putting a cap on AREF and not AVCC? I've messed a ton with the code and trouble shooting, I'm sure it is a wiring issue related to the caps as removing them eliminates the error. Of course, it also eliminates any filtering as well, I'd like to keep that.
So, should I only be putting a cap on AREF and not AVCC? I've messed a ton with the code and trouble shooting, I'm sure it is a wiring issue related to the caps as removing them eliminates the error. Of course, it also eliminates any filtering as well, I'd like to keep that.