/******************************************************************************
* @fn halJoystickGetDir
*
* @brief
* This function utilizes the ADC to give an indication of the current
* position of the joystick. Current support is for 90 degrees
* positioning only.
*
* The joystick control is encoded as an analog voltage. Keep on reading
* the ADC until two consecutive key decisions are the same.
*
* Meassured values from the ADC:
* -------------------------------------------
* |Direction | Voltage | Value | Range |
* -------------------------------------------
* |UP | 0.31 V | 0x0D | 0x00-0x27 |
* |DOWN | 1.16 V | 0x31 | 0x28-0x3B |
* |LEFT | 1.62 V | 0x45 | 0x3C-0x49 |
* |RIGHT | 1.81 V | 0x4D | 0x4A-0x53 |
* |CENTER | 2.12 V | 0x5A | 0x54- |
* -------------------------------------------
*
* Parameters:
*
* @param void
*
* @return uint8
* DOWN: Joystick direction is down (270 degrees)
* LEFT: Joystick direction is left (180 degrees)
* RIGHT: Joystick direction is right (0 degrees)
* UP: Joystick direction is up (90 degrees)
* CENTER: Joystick direction is centred (passive position)
*
******************************************************************************/
uint8 halJoystickGetDir(void)
{
uint16 adcValue;
uint8 direction, directionOld;
do {
directionOld = direction;
adcValue = adcSampleSingle(ADC_REF_AVDD, ADC_9_BIT, \
HAL_BOARD_IO_JOYSTICK_ADC_CH);
// Only use 7 out of the 9 bits
adcValue = (adcValue & 0x7FC0) >> 8;
if (adcValue < 0x28) {
direction = HAL_JOYSTICK_EVT_UP;
} else if (adcValue < 0x3C) {
direction = HAL_JOYSTICK_EVT_DOWN;
} else if (adcValue < 0x4A) {
direction = HAL_JOYSTICK_EVT_LEFT;
} else if (adcValue < 0x54) {
direction = HAL_JOYSTICK_EVT_RIGHT;
} else {
direction = HAL_JOYSTICK_EVT_CENTER;
}
} while(direction != directionOld);
return direction;
}
/***********************************************************************************
* @fn getSamples
*
* @brief Get ADC Samples of Specified Channel and Average
*
* @param none
*
* @return none
*/
unsigned int getSamples(unsigned int chan)
{
unsigned char loop;
unsigned int avg = 0; // Clear average variable
for (loop=0;loop<NUMSAMPLES;loop++) { // Loop
avg = avg + adcSampleSingle(ADC_REF_AVDD,ADC_12_BIT,chan); // Accumulate samples
}
avg = avg >> SAMPLESHIFT; // Calculate average
return avg; // Return average
}
/************************************************************************************
* @fn halJoystickPushed
*
* @brief
* This function detects if the joystick is being pushed. The function
* implements software debounce. Return true only if previuosly called
* with joystick not pushed. Return true only once each time the joystick
* is pressed.
*
* Parameters:
*
* @param void
*
* @return uint8
* 1: Button is being pushed
* 0: Button is not being pushed
*
******************************************************************************/
uint8 halJoystickPushed(void)
{
uint8 value, active;
uint8 i;
static uint8 prevValue = 0;
uint16 adcValue;
// Criterion for button pushed:
// 3 times joystick active and in center position
value = 1;
for (i=0; i<3; i++) {
active = MCU_IO_GET(HAL_BOARD_IO_JOY_MOVE_PORT, HAL_BOARD_IO_JOY_MOVE_PIN);
adcValue = adcSampleSingle(ADC_REF_AVDD, ADC_9_BIT, \
HAL_BOARD_IO_JOYSTICK_ADC_CH);
// Only use 7 out of the 9 bits
adcValue = (adcValue & 0x7FC0) >> 8;
if (! active || adcValue < 0x54) {
// Joystick not active or not in center position
value = 0;
break;
}
halMcuWaitUs(3);
}
if (value){
if (!prevValue){
value = prevValue = 1;
halMcuWaitMs(100);
}
else {
value = 0;
}
}
else{
prevValue = 0;
}
return value;
}
