I'm looking to use the GPIO pins to control a remote control car by activating the switches in the controller using a transistor as a switch.
The controller is powered by 2 AA batteries (3V) and the pins for the different controls are tied high normally. When the switch is activated the pin is tied to Zero (-)
I was considering the following attached circuit and before I wire it all up I thought it might be a good idea to make sure I have it right. I have basic-ish knowledge of electronics and don't want to damage my Raspberry Pi
In my head this ties the pin to 3V until a Base current is applied.
When the current is applied the circuit effectively become 3V - R1 - Pin - Q1 (0Ohm) - OV, so Pin is tied to 0V.
Also, any suggestions for R1 and R2
R1 - 1KOhm
R2 - 10KOhm (Base)
I checked the current across the switches (so inline) and it was reading 0.1mA. With a 10KOhm resistor and 3.3V from the GPIO I would be providing 0.33mA (I think), so way more than enough to saturate the Base.
Any and all tips appreciated. You could save a Raspberrp Pi from being being fried...