Attiny45 Pin State on Power Up

Development Boards MicroMod
1

What is the pin state during power up, Im using an ATtiny45 to control a few relays and when powered up it turns them on for a short time, once everything is settled everything runs fine, they are being controlled via pulse width from a RC radio, is there a way to force the output pins to stay high or low during power up?

Thanks

2

I/O pins are tri-stated on reset. You will have to pull them up or down with resistors if you want them to have a known value on power up.

3

I pull them low to control the relays, how and what resistor would I use to keep them high on reset?

4

100K to Vdd on each input pin should work well.

5

Thanks, I’m kinda new to all of this, it’s nice not to get such help for a simple question lol