Originally Posted by baball
Read judge post. Don't need regulator...
I know that...where do i say use it?
Actually, heres pics of the power mod, except you dont need to add the regulator
Originally Posted by judges
And yes, according to the Teensy specs, it should only run at 8 MHz on 3.3V. I'll also update this.
The AVR processor is not specified to run faster than 8 MHz when running at 3.3 volts, even though it often can operate at 16 MHz at room temperature.
You do NOT need to replace the 16 MHz crystal. Just set the CPU prescaler to 0x01 so the processor runs at 8 MHz.
#define CPU_PRESCALE(n) (CLKPR = 0x80, CLKPR = (n))
// set for 8 MHz clock because 3.3 volts
// rest of program....]
You also need to edit your Makefile to change F_CPU to 8000000.
# Processor frequency.
# Normally the first thing your program should do is set the clock prescaler,
# so your program will run at the correct speed. You should also set this
# variable to same clock speed. The _delay_ms() macro uses this, and many
# examples use this variable to calculate timings. Do not add a "UL" here.
F_CPU = 8000000
Looking at the schematic, don't you tie the 3.3v nor vcc to the teensy 5v. Your hardware connections doesn't show the 3.3 volt tie to the teensy