[TriEmbed] Large Wall Charts

[Pete Soper]

On 04/14/2014 02:25 PM, Grawburg wrote:
> You have stated it correctly, sir.

In that case I agree with Martin Brooke. Since you need, at a minimum, 
one bit into the microcontroller and one bit out of it, that's also 
enough to sense the pushbutton and turn the gadget on and then back off, 
emulating any kind of latching behavior you'd like. So perhaps all that 
is needed is a FET or FET/relay combination and some signal 
conditioning/buffering to protect the RPI's gates.

-Pete
> -----Original Message-----
>>   
>>
>> I don't think your requirements were well understood. I gathered you
>> want to push a momentary contact switch and have some gadget turn on and
>> stay on until some period of time has passed or a microcontroller
>> preempts the time period by reseting the circuit. The microcontroller
>> would use 3.3 volt digital I/O pins like those of a Raspberry Pi system
>> for sensing the and controlling the latch state and the gadget might be
>> powered by the latch circuit or it might require some other switch like
>> a relay.
>>
>> Have I got that right?
>>
>>
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