I would like to save battery life by turning on the DFPlayer using an arduino output pin only when needed...
The problem very similar to the one discussed here: https://forum.arduino.cc/index.php?topic=512879.0
Specs/setup: - arduino pro (3.3v) - DFPlayer mini: 5V, draws ~25mA when idle, and ~100mA when playing - Arduino and DFPlayer powered by breadboard connected to 5V
I've tried both NPN (P2N222A) and PNP (2N3906) transistors, with limited success. The mp3 player gets power but just plays stuttering/grinding noises - a low power scenario. I see the same symptom when the player is connected to 3.3v (as opposed to 5).
The PNP setup looks like this;
(For me, the emitter is hooked up directly to the 5V on the breadboard)
QUESTIONS: - Is it even possible to use a 3.3v pin on the arduino to switch on a 5V device with a transistor? - Is there an easier/better way to attempt this besides a transistor switch?