mramos1
Active Member
I bought my son a used car and we put in a new setero (one with an input earphone jack he can plug his MP3 player in). He was telling me it had a click or something. I went to listen. Turns out the preamp on the input jack/MP3 on the radio does not have enough gain. It is a cheap no name brand but it had SD, USB and the input jack on the front of it.
I do not want to open the radio (as it is installed and a pain to get it out).
My thought. I have an amp I can put in the trunk and there is a large wire I traced it to the battery (was shocked it had a fuse). Frame is ground. But they did not run an ignition wire to the radio area.
The AMP needs that to turn it on. If I jumper that, the amp is always on.
My thought.. I small board in the trunk that taps one of the incoming speaker wires (now an amp input) to an opto going to a pic (16F683) running 31Khz (low power). Using the pic ADC via the opto. If the PIC sees audio I know the radio is on, I power a transistor and realy to power the AMP (power/ignition).
Anyone have a better idea? Simpler is fine.
I do not want to open the radio (as it is installed and a pain to get it out).
My thought. I have an amp I can put in the trunk and there is a large wire I traced it to the battery (was shocked it had a fuse). Frame is ground. But they did not run an ignition wire to the radio area.
The AMP needs that to turn it on. If I jumper that, the amp is always on.
My thought.. I small board in the trunk that taps one of the incoming speaker wires (now an amp input) to an opto going to a pic (16F683) running 31Khz (low power). Using the pic ADC via the opto. If the PIC sees audio I know the radio is on, I power a transistor and realy to power the AMP (power/ignition).
Anyone have a better idea? Simpler is fine.
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