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dda
dda
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Avoiding false rising and falling edge when using demultipexordemultiplexer

I have 8 sets of 8 push buttons. There is a teensyTeensy and a demultiplexordemultiplexer. The demultipexordemultiplexer has 8 outputs. When an output is selected it is pulled low. Each output is connected to a group of 8 push buttons. The 8 push buttons are then connected to 8 pullup inputs on the teensyTeensy.

Each group of 8 push buttons is connected to a unique demultipexordemultiplexer output, but all the push buttons are connected to the same 8 inputs on the teensyTeensy. AKAThat is, push button #1 in group 1 shares a teensyTeensy input with push button #1 in group 2. The pushbuttonspush buttons are isolated from each other with diodes.

I'm using bounce.hbounce.h for debouncing. It looks for rising and falling edges.

The problem is this:

  • Push button #1 in group #1 is pressed, pulling that input low, causing a falling edge to be detected. This is good.
  • The demultipexordemultiplexer shifts to group #2, where the #1 button hasn't been pressed, and thus is high.
  • Because both #1 buttons in group #1 and #2 share the same input line, the teensy seeTeensy sees this change as a rising edge. This is undesired.

What is the better approach to this?

Thanks,

  • Dan

Dan

Avoiding false rising and falling edge when using demultipexor

I have 8 sets of 8 push buttons. There is a teensy and a demultiplexor. The demultipexor has 8 outputs. When an output is selected it is pulled low. Each output is connected to a group of 8 push buttons. The 8 push buttons are then connected to 8 pullup inputs on the teensy.

Each group of 8 push buttons is connected to a unique demultipexor output, but all the push buttons are connected to the same 8 inputs on the teensy. AKA push button #1 in group 1 shares a teensy input with push button #1 in group 2. The pushbuttons are isolated from each other with diodes.

I'm using bounce.h for debouncing. It looks for rising and falling edges.

The problem is this:

  • Push button #1 in group #1 is pressed, pulling that input low, causing a falling edge to be detected. This is good.
  • The demultipexor shifts to group #2, where the #1 button hasn't been pressed, and thus is high.
  • Because both #1 buttons in group #1 and #2 share the same input line, the teensy see this change as a rising edge. This is undesired.

What is the better approach to this?

Thanks,

  • Dan

Avoiding false rising and falling edge when using demultiplexer

I have 8 sets of 8 push buttons. There is a Teensy and a demultiplexer. The demultiplexer has 8 outputs. When an output is selected it is pulled low. Each output is connected to a group of 8 push buttons. The 8 push buttons are then connected to 8 pullup inputs on the Teensy.

Each group of 8 push buttons is connected to a unique demultiplexer output, but all the push buttons are connected to the same 8 inputs on the Teensy. That is, push button #1 in group 1 shares a Teensy input with push button #1 in group 2. The push buttons are isolated from each other with diodes.

I'm using bounce.h for debouncing. It looks for rising and falling edges.

The problem is this:

  • Push button #1 in group #1 is pressed, pulling that input low, causing a falling edge to be detected. This is good.
  • The demultiplexer shifts to group #2, where the #1 button hasn't been pressed, and thus is high.
  • Because both #1 buttons in group #1 and #2 share the same input line, the Teensy sees this change as a rising edge. This is undesired.

What is the better approach to this?

Thanks,

Dan

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Daniel
Daniel
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Avoiding false rising and falling edge when using demultipexor

I have 8 sets of 8 push buttons. There is a teensy and a demultiplexor. The demultipexor has 8 outputs. When an output is selected it is pulled low. Each output is connected to a group of 8 push buttons. The 8 push buttons are then connected to 8 pullup inputs on the teensy.

Each group of 8 push buttons is connected to a unique demultipexor output, but all the push buttons are connected to the same 8 inputs on the teensy. AKA push button #1 in group 1 shares a teensy input with push button #1 in group 2. The pushbuttons are isolated from each other with diodes.

I'm using bounce.h for debouncing. It looks for rising and falling edges.

The problem is this:

  • Push button #1 in group #1 is pressed, pulling that input low, causing a falling edge to be detected. This is good.
  • The demultipexor shifts to group #2, where the #1 button hasn't been pressed, and thus is high.
  • Because both #1 buttons in group #1 and #2 share the same input line, the teensy see this change as a rising edge. This is undesired.

What is the better approach to this?

Thanks,

  • Dan