I’m trying to put together a guitar pedal that will let me change loops as well as channels on my amplifier. The approach I have taken is to have relays do the switching and control them with attiny chips that I have programmed with my Arduino. Each relay (5v) has an chip (attiny85) which also controls an LED. Four of these are connected to an attiny84 which is dealing with the switch inputs and control voltages to the 4 attiny85s.
Now the issue I am having is power, I have tried using a L7805CP 5v regulator to convert my 9v (1.2A) adapter but as soon as I connect each chip and relay module to the source the voltage on the output pin of the regulator drops. The measure of voltage after each module is connected is 5v, 4.55v, 3.52v, 2.92v and then 2.27v. I had the same results with another 5v regulator as well as a 5v DC adapter. Each feed has been decoupled with a 100R resistor and 100uF cap.
Could someone explain why this might be happening as I am not sure? I have powered multiple pedal circuits in a single enclosure before without issue so cannot work out what is happening here.