/* Initialize stuff:
* - Start Vref module
* - Clear all fail flags
* - Internal reference (default: external vcc)
* - Mux between a and b channels (b channels)
* - Calibrate with 32 averages and low speed
* - When first calibration is done it sets:
* - Resolution (default: 10 bits)
* - Conversion speed and sampling time (both set to medium speed)
* - Averaging (set to 4)
*/
void ADC_Module::analog_init() {
// default settings:
/*
- 10 bits resolution
- 4 averages
- vcc reference
- no interrupts
- pga gain=1
- conversion speed = medium
- sampling speed = medium
initiate to 0 (or 1) so the corresponding functions change it to the correct value
*/
analog_res_bits = 0;
analog_max_val = 0;
analog_num_average = 0;
analog_reference_internal = 1;
var_enableInterrupts = 0;
pga_value = 1;
conversion_speed = 0;
sampling_speed = 0;
// the first calibration will use 32 averages and lowest speed,
// when this calibration is over the averages and speed will be set to default by wait_for_cal and init_calib will be cleared.
init_calib = 1;
fail_flag = ADC_ERROR_CLEAR; // clear all errors
// Internal reference initialization
VREF_TRM = VREF_TRM_CHOPEN | 0x20; // enable module and set the trimmer to medium (max=0x3F=63)
VREF_SC = VREF_SC_VREFEN | VREF_SC_REGEN | VREF_SC_ICOMPEN | VREF_SC_MODE_LV(1); // (=0xE1) enable 1.2 volt ref with all compensations
// select b channels
*ADC_CFG2_muxsel = 1;
// set reference to vcc/external
setReference(ADC_REF_EXTERNAL);
// set resolution to 10
setResolution(10);
// calibrate at low speed and max repetitions
setAveraging(32);
setConversionSpeed(ADC_LOW_SPEED);
setSamplingSpeed(ADC_LOW_SPEED);
// begin init calibration
calibrate();
}
/* Initialize stuff:
* - Start Vref module
* - Clear all fail flags
* - Internal reference (default: external vcc)
* - Mux between a and b channels (b channels)
* - Calibrate with 32 averages and low speed
* - When first calibration is done it sets:
* - Resolution (default: 10 bits)
* - Conversion speed and sampling time (both set to medium speed)
* - Averaging (set to 4)
*/
void ADC_Module::analog_init() {
// default settings:
/*
- 10 bits resolution
- 4 averages
- vcc reference
- no interrupts
- pga gain=1
- conversion speed = medium
- sampling speed = medium
initiate to 0 (or 1) so the corresponding functions change it to the correct value
*/
analog_res_bits = 0;
analog_max_val = 0;
analog_num_average = 0;
analog_reference_internal = 2;
var_enableInterrupts = 0;
pga_value = 1;
conversion_speed = 0;
sampling_speed = 0;
calibrating = 0;
fail_flag = ADC_ERROR_CLEAR; // clear all errors
num_measurements = 0;
// select b channels
// *ADC_CFG2_muxsel = 1;
setBit(ADC_CFG2, ADC_CFG2_MUXSEL_BIT);
// set reference to vcc
setReference(ADC_REF_3V3);
// set resolution to 10
setResolution(10);
// the first calibration will use 32 averages and lowest speed,
// when this calibration is over the averages and speed will be set to default by wait_for_cal and init_calib will be cleared.
init_calib = 1;
setAveraging(32);
setConversionSpeed(ADC_LOW_SPEED);
setSamplingSpeed(ADC_LOW_SPEED);
// begin init calibration
calibrate();
}
/* Waits until calibration is finished and writes the corresponding registers
*
*/
void ADC_Module::wait_for_cal(void)
{
uint16_t sum;
while(*ADC_SC3_cal) { // Bit ADC_SC3_CAL in register ADC0_SC3 cleared when calib. finishes.
}
if(*ADC_SC3_calf) { // calibration failed
fail_flag |= ADC_ERROR_CALIB; // the user should know and recalibrate manually
}
__disable_irq();
if (calibrating) {
sum = *ADC_CLPS + *ADC_CLP4 + *ADC_CLP3 + *ADC_CLP2 + *ADC_CLP1 + *ADC_CLP0;
sum = (sum / 2) | 0x8000;
*ADC_PG = sum;
sum = *ADC_CLMS + *ADC_CLM4 + *ADC_CLM3 + *ADC_CLM2 + *ADC_CLM1 + *ADC_CLM0;
sum = (sum / 2) | 0x8000;
*ADC_MG = sum;
calibrating = 0;
}
__enable_irq();
// the first calibration uses 32 averages and lowest speed,
// when this calibration is over, set the averages and speed to default.
if(init_calib) {
// set conversion speed to medium
setConversionSpeed(ADC_MED_SPEED);
// set sampling speed to medium
setSamplingSpeed(ADC_MED_SPEED);
// number of averages to 4
setAveraging(4);
init_calib = 0; // clear
}
}
