I've been running this setup for a week or so. Should I worry that the MAX232 is driving the RX line to the '328p higher than its Vcc (3.3 volts) ? Possibly as high as 4.8 volts?
Maybe I'll add a resistor/voltage divider on that signal.
William
using 5 volt home-made MAX232/programming cable with 3.3 volt JeeNode?
(2 posts) (2 voices)-
Posted 18/05/2010 03:56:21
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A 1 k? resistor in series with the input side of the ATmega should be sufficient. So that over-voltage on the input flows away to VCC via the internal ESD protection diode. Maybe there's already something in there now which has that same effect.
Posted 18/05/2010 07:39:42