Joystick
Description
The EVK1101 provides a joystick to design Human to Machine Interface for software developments.
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Pinout
The joystick inputs are low level active. (ie : the PVR register value is 0 when the joystick is set in a direction and/or pressed, and 1 otherwise)
The pinout is as follow :
| Joystick Pin | Joystick Direction | GPIO Name | Alternate function used |
|---|---|---|---|
| Joy_A | LEFT | PB 6 | SCAN_4 |
| Joy_B | UP | PB 7 | SCAN_5 |
| Joy_C | DOWN | PB 8 | SCAN_6 |
| Joy_D | RIGHT | PB 9 | SCAN_7 |
| EXTINT | PUSH | PA 13 | EXTINT_8 |
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Using Interrupts
In order to use the joystick, two ways are available :
- Polling on the GPIO Port Value Register
- Using GPIO interrupts to get state changes
Using GPIO interrupts need to :
- Register an interrupt handler for the input (depending on the compiler you are using),
- Set the GPIO control bit for the input,
- Set the GPIO glitch filter bit for the input,
- Configure the GPIO interrupt mask bit for the input to act either on rising edge, falling edge or input change (this mode should be the better for the joystick),
- Set the GPIO interrupt enable bit for the input.
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