Standalone 3.3v Arduino problems

Hi guys

I followed this guide to build a standalone Arduino. It worked great on 5v. When adding power using a 9v battery - this standard "brick" battery - the output voltage was around 5v. The thing is that I want the Arduino to operate on 3.3v. I switched the 16 MHz clock crystal with a 8 Mhz one. I also swapped the L7805CV voltage regulator with a LM1117 regulator. I just swapped these two components without changing the pins and such.

My problem is that the microchip is only getting around 0.35 volt? The LM1117 regulator is getting really hot. What am I doing wrong here?


Are you sure you have the right pin assignments for the lm1117?

Sounds like you have the input and output pins reversed on the voltage regulator.