I am using an attiny84 and am trying to run 4 pwm led's and have a isp header setup. Unfortunately the pwm pins on the attiny84 and the isp pins overlap so I want to reuse those pins for both purposes. I read on this forum that putting a 1k resistor on the non-ISP side of the circuit should isolate it and should allow for isp-programming, however its not working for me.
My setup is (ISP/PWM PIN) ---- (LED) ---- (1K resistor) --- (GND) | ----- (ISP header)
The error I am getting is
Binary sketch size: 3828 bytes (of a 8192 byte maximum) avrdude: please define PAGEL and BS2 signals in the configuration file for part ATtiny84 avrdude: Yikes! Invalid device signature. Double check connections and try again, or use -F to override this check.
How do I reuse the isp pins properly for both isp programming and the led pwm to work properly? Also are there any negatives for switching to software serial and leaving the isp pins dedicated? I would rather not since I might need the extra pins for other uses.