The EVK1101 provides two push buttons to design Human to Machine Interface for software developments.
Pinout
The push buttons inputs are low level active. (ie: the PVR register value is 0 when the button is pressed, and 1 otherwise) The pinout is as follows:
| Push Button | GPIO Name | Alternate function used |
|---|---|---|
| 1 | PB 2 | EIC/EXTINT 6 |
| 2 | PB 3 | EIC/EXTINT 7 |
Using Interrupts
In order to use a push button, two ways are available:
-
Polling on the GPIO Port Value Register,
-
Using GPIO interrupts to get state changes.
Using GPIO interrupt needs to:
-
Register an interrupt handler for the input (depending on the compiler you are using),
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Set the GPIO control bit for the input,
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Set the GPIO glitch filter bit for the input,
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Configure the GPIO interrupt mask bit for the input to act either on rising edge, falling edge or input change,
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Set the GPIO interrupt enable bit for the input.