Hello everyone,
For a project I am multiplexing several pin outputs of a microcontroller (Chipkit max32) to a different controller (with not enough inputs to wire each separately)
I recall using this method before for some older project but I cannot recall how I solved the problem I have now.
The schematic I included does work for individual outputs but when using multiple signals the values do not add up as they should.
The 5V for the schematic is supplied by a LM7805C.
The opamp is a LM324.
The optocouplers are all four gates from a TIL193.
now the Vout is not stable when opening multiple optocouplers, can I solve this using different resistors/optocouplers? a change in schematic perhaps?
The output must be able to see which button is pressed based on the Vout. this is read via a ADC from the second controller (but initial tests use the chipkit's microprocessor and ADC)
For a project I am multiplexing several pin outputs of a microcontroller (Chipkit max32) to a different controller (with not enough inputs to wire each separately)
I recall using this method before for some older project but I cannot recall how I solved the problem I have now.
The schematic I included does work for individual outputs but when using multiple signals the values do not add up as they should.
The 5V for the schematic is supplied by a LM7805C.
The opamp is a LM324.
The optocouplers are all four gates from a TIL193.
now the Vout is not stable when opening multiple optocouplers, can I solve this using different resistors/optocouplers? a change in schematic perhaps?
The output must be able to see which button is pressed based on the Vout. this is read via a ADC from the second controller (but initial tests use the chipkit's microprocessor and ADC)
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