Question about the Count Command.

[mister_e]

Ralph suggestion is quite good, the only problem i see, is when the audio signal will cross the Zero, the amp could turn off.

mmm... in conjunction with the ralph suggestion, connect the op-amp output to the PIC, check the signal, wait let's say 100 ms or more and redo the test. If both tests are positive, turn on the amp, if both negative, turn off the amp.

Now it's time to do some home work guy. We provided more than enough stuff to do the whole thing... even on more than one thread

1. You have a snip of code
2. you have a heap of idea how to do it
3. the circuit is virtually in the air... look !!! you see it??

Probably... the op-amp could be skip if you use the PIC comparator. If you keep the op-amp, you can do the whole project with a simple nifty 10F serie without analog stuff on

[NavMicroSystems]

Ralph suggestion is quite good, the only problem i see, is when the audio signal will cross the Zero, the amp could turn off.

Steve, I was assuming there is a small PIC at the output of the OpAmp.
(This was why had suggested to supply the OpAmp with 5V)
(The positive Rail of the OpAmp would limit the voltage you feed into the PICs)

However,
let's stop here, TEAR has probably got more info than he'll ever need or he can cope with.

[nomada]

Hi Michael and of course all the others

I supposed that in your post #3 you said that you intend to get the audio signal from the link between the stereo deck and the amplifier, and in post #7 you wrote about getting the signal from speakers wires, which one is the correct one?

Besides a lot of other things, at my company we produce audio amplifiers (OEM regime) from 100W to 3000W (2 channels). One thing I've learned, turning on a amplifier with signal present at the inputs when the amplifier has no soft-start feature or other kind of (BUMP) protection will surely damage the speakers, please take care in your aproach regarding the method of turning on the power while monitoring the ammount of signal at the inputs.

I suppose that you are really determined to use a PIC, because as all the others had already said there are "other" ways to get the same result.

Keep us informed

[mister_e]

Nomada have a good point about the soft start for sure, this is why we suggest a op-amp at the input with a wide gain to compensate, but i do understand your point.

BTW last suggestion, since more than everything has been covered, and we still don't know in wich car it will be installed...

Most of those deck have a turn-on lead for factory amp and/or electric antenna and such. The use of a volmeter on the back connector of the radio will show you the truth. The easy solution of using the ignition/accessory wire it's still working too.


http://www.installdr.com/QuickWiring.html or www.google.com for radio pinout

And of course, the best one that need a few experience.. open the radio and probe the circuit to find a remote, use a MOSFET, Transistor ,CMOS buffer to provide your turn-on.

That's all for me too