If I use an LM317 Voltage Regulator
effectively raising the voltage but keeping the proportions
and 0 - 5V Variable supply from the ATTiny ouput pin)
Here's a photo of my breadboard circuit...
You'd need a transistor to drive the relay, so no, do not ditch the transistor. It's just fine.In this circuit, the input at pin2 goes low when the button is pressed, and from what I can see that looks correct. Does the code expect the input to be active low or high?