What would be the best way of using an Arduino to operate the pictured remote control circuit board? My initial instinct would be to leave the batteries in the remote and use a separate transistor for each of the five switches, connecting wires (solder or electrical tape) to the two sides of each button and the base to an Arduino output pin. I'm certainly not an expert, so I wanted to confirm whether (a) that would work and (b) if there's a much better way. The control is normally powered by two AAA batteries.
Thanks in advance for your help
Note: I've tried to simply record and emit the IR signals from the remote using my Arduino, but have thus far been unsuccessful, so want another way of using the Arduino to control my fan: Unable to control fan with IR circuit despite capturing and reproducing the IR transmissions