I am trying to use an standalone Atmega328p chip powered by 5v battery to turn on/off the power (12v battery) to a drone, and mimic pushing one of the momentary buttons on the drone circuit (start/stop recording).
I have tried successfully using a TIP120 transistor to switch on/off the 12v power supply to the drone circuit. Next I decided to use a CD4066 chip to mimic the push button on the drone. Now this circuit stops working, and the voltmeter is reading 7-8 volts. If i remove the TIP120, and just power the drone directly, the CD4066 chip successfully toggles the button, and the voltmeter reads 5v.
With the TIP120 back in place, it seems that when i connect the power to the CD4066 chip, the arduino gets 7-8 volts all of a sudden. But when i cut that wire ( green circle/cross) the voltage goes back to 5v and the remaining part of the circuit works fine. I can't seem to have both switches be operable at once.
I could just use a relay to push the switch for me, but it's big and bulky.
What should i poke first??