I have designed this audio switch. 1 out of 4 TRRS inputs is selected.
I am testing it but it does nothing.
I press the switch to switch the next channel and nothing works.
The idea here is:
- the 555 debounces the key and a pulse is injected on the flipflop when the button is pressed.
- the flipflop is a 2 bit counter, producing a sequence from 00 to 11 as the button is pressed repeatedly.
- the two bits from the flip flop selects one of the four channels of the MAX359E switch.
- The leds display 00, 01, 10, 11, depending on the input selected, obviously... 😃
- I am not sure what to do with the mic input in relation to the input/output capacitor. This is because some TRRS inputs, like iPhone's, send a voltage on the mic line, to supply the mic. If I put a capacitor it will remove that voltage...
Any ideas why it is not working? I may have connected something wrong on the test board. I have double checked the connections several times but at this point I may be tired and not seeing the problem or the circuit is bad designed...
Any ideas? Thanks
EDIT: I have modified the circuit according to