I have a CHI040 and I want to turn on a DFPlayer same as in the SPE035. So I have hooked it up as below.
The reason I want to do this is the player uses a huge amount of current when doing nothing. It may need to turn on for 30 seconds a day, at the moment when it is idle the circuit consumes 100+ mA. If the speakers are not connected the current is quite low, when they are connected the current goes up. If I connect the GND of the speaker to that of the DFPlayer, the player does not work at all.
So the amp must be drawing current via the GND and 4.5V.
The reason I want to do this is the player uses a huge amount of current when doing nothing. It may need to turn on for 30 seconds a day, at the moment when it is idle the circuit consumes 100+ mA. If the speakers are not connected the current is quite low, when they are connected the current goes up. If I connect the GND of the speaker to that of the DFPlayer, the player does not work at all.
So the amp must be drawing current via the GND and 4.5V.