I have an ATtiny85 which had a simple program PWMing its output pins to pulse some LEDs.
While messing round trying to wire up Raspberry Pi SPI to program it with avrdude, it's gone into a state where when powered up it pulses PB0,PB1,PB2,PB3,PB4 at maybe 5 Hz (guessing by eye), even if I hold reset to ground (which I would expect to make it an SPI slave). I never got as far as actually feeding in any program code - just using avrdude to check that it can see the ATtiny85, which it could till this happened.
Is this broken or is it some state I can fix?