555 as on & off switch
Thanks onion
Oh, all and any help is appreciated.
Enabling the 555 is by connecting the output Pin 3. It may well be a route to deny the chip its +5V or deny Ground or some other method ?
Enabling the resistors has been to connect all at one end, and then, with each different key to a particular resistor, the sample changes pitch. I realise that's probably not the best method, but it seemed to work as a route for pitch changing.
I'd like to know of other methods, where an on/off switch and further processing of a voltage are implemented. 1V per Octave would be the best, similar to most analog synths, but I figured the design needn't be too difficult for simple resistor changing.
Signals per line are: One completes a wire to wire connection, the connection being from Pin 3 to the 4040's. The other affects the VR which controls the pitch of the sample, this is where each resistor is to run to.
Progress today has been to find a PC817 opto isolator and solder it up. The PC817 is connected to +5V (through 1.5k resistor) and the other leg goes to a common Ground rail that runs along all the switches and works when the switch is pressed. Now all the keys trigger the sample. It's a butt head method though, because now I have a Ground rail !
hmm, maybe the Ground rail connection can start the 555 ?
I'm open to any and all ideas..finding proven methods online might give a diagram too to work with