Anyone know of any MSP430 code/schematics for this?
I've been digging in Google w/o any luck...
There are different approaces. Some jacks do have a separate switch which can be checked by the MSP. Or you put a pullup on the signal line and detect whether input voltage is VCC or below (indicating that some signal, but not an empty plug has been inserted). It depends on your hardware and the signal source. There's no generic answer.
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Thanks, Jens.
Do you have an example on how it would work w/ the 5 contact 3.5mm plugs like this one?
I'm using 1/2/4 already but can't figure out what to do w/ 3/5 to sense a plug has been inserted. They're normally used to switch between headphones vs. speakers from what I've dug up, so 3/5 normally would go to the speakers if you have them, but I just want to use them to sense that a plug is in.
Hi,
there is some some cool stuff here, hope helpfull!
http://electronics.stackexchange.com/questions/1647/how-does-an-audio-jack-detect-when-a-speaker-is-plugged-in
regards,
sri.
Regards,
Sri.
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You can put a pullup resistor on 3/5. E.g. 50k each to VCC. The input on 4/2 is then VCC if no plug is inserted and breaks down to whatever if yu plug something in. You can go even further and use 5k pullup on 3/5 and 47k pulldown on 4 and 2. This will again have the signal on VCC if no plug is inserted, but ensure 0V if a plug without signal is inserted (in the first case without pulldown, an unconnected plug would lead to an open input and therefore an indeterminate state). If you use an audio line signal, a 47k load is expected anyway.
Or you connect 3/5 to two port pins and periodically toggle their output state and check for a change in the input state on 2/4. This too will let you detect whether the socket is empty or not.
Of cource you can only check on one of the two channels.
Sri: That stackexchange article was pretty useless...I found that w/ Google already and it essentially doesn't say much useful except to say someone else did it.
I was experimenting w/ the pullup technique you mentioned before and making some progress. This post added a lot more clarity :-)