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Code Issues Releases Activity

Extended analogRead/Write API to support difference ADC/DAC resolutions.

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This commit is contained in:
Cristian Maglie 2012-08-04 11:27:46 +02:00
parent 66747ec688
commit 181a3fbbe4
3 changed files with 41 additions and 15 deletions
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33
hardware/arduino/sam/cores/arduino/wiring_analog.c
View File

@ -22,10 +22,24 @@
extern "C" {
#endif
static int _analogResolution = 10;
static int _readResolution = 10;
static int _writeResolution = 8;
void setAnalogResolution(int res) {
_analogResolution = res;
void analogReadResolution(int res) {
_readResolution = res;
}
void analogWriteResolution(int res) {
_writeResolution = res;
}
static inline uint32_t mapResolution(uint32_t value, uint32_t from, uint32_t to) {
if (from == to)
return value;
if (from > to)
return value >> (from-to);
else
return value << (to-from);
}
eAnalogReference analog_reference = AR_DEFAULT;
@ -69,6 +83,7 @@ uint32_t analogRead(uint32_t ulPin)
// Read the value
ulValue = adc_get_latest_value(ADC);
ulValue = mapResolution(ulValue, 10, _readResolution);
// Disable the corresponding channel
adc_disable_channel( ADC, ulChannel );
@ -98,6 +113,7 @@ uint32_t analogRead(uint32_t ulPin)
// Read the value
ulValue = adc12b_get_latest_value(ADC12B) >> 2;
ulValue = mapResolution(ulValue, 12, _readResolution);
// Stop the ADC12B
// adc12_stop( ADC12B ) ; // never do adc12_stop() else we have to reconfigure the ADC12B each time
@ -142,15 +158,11 @@ uint32_t analogRead(uint32_t ulPin)
// Read the value
ulValue = adc_get_latest_value(ADC);
ulValue = mapResolution(ulValue, ADC_RESOLUTION, _readResolution);
// Disable the corresponding channel
adc_disable_channel(ADC, ulChannel);
// Map result into user selected resolution
if (_analogResolution > ADC_RESOLUTION)
ulValue <<= _analogResolution - ADC_RESOLUTION;
if (_analogResolution < ADC_RESOLUTION)
ulValue >>= ADC_RESOLUTION - _analogResolution;
break;
// Compiler could yell because we don't handle DAC pins
@ -244,12 +256,15 @@ void analogWrite(uint32_t ulPin, uint32_t ulValue) {
}
// Write user value
ulValue = mapResolution(ulValue, _writeResolution, DACC_RESOLUTION);
dacc_write_conversion_data(DACC_INTERFACE, ulValue);
return;
}
}
if ((attr & PIN_ATTR_PWM) == PIN_ATTR_PWM) {
ulValue = mapResolution(ulValue, _writeResolution, PWM_RESOLUTION);
if (!PWMEnabled) {
// PWM Startup code
pmc_enable_periph_clk(PWM_INTERFACE_ID);
@ -280,6 +295,7 @@ void analogWrite(uint32_t ulPin, uint32_t ulValue) {
const uint32_t TC = VARIANT_MCK / 2 / TC_FREQUENCY;
// Map value to Timer ranges 0..255 => 0..TC
ulValue = mapResolution(ulValue, _writeResolution, TC_RESOLUTION);
ulValue = ulValue * TC;
ulValue = ulValue / TC_MAX_DUTY_CYCLE;
@ -338,6 +354,7 @@ void analogWrite(uint32_t ulPin, uint32_t ulValue) {
// Defaults to digital write
pinMode(ulPin, OUTPUT);
ulValue = mapResolution(ulValue, _writeResolution, 8);
if (ulValue < 128)
digitalWrite(ulPin, LOW);
else

11
hardware/arduino/sam/cores/arduino/wiring_analog.h
View File

@ -57,11 +57,18 @@ extern void analogWrite( uint32_t ulPin, uint32_t ulValue ) ;
extern uint32_t analogRead( uint32_t ulPin ) ;
/*
* \brief Set the resolution of analogRead return values. Default is 10 bits (0..1024).
* \brief Set the resolution of analogRead return values. Default is 10 bits (range from 0 to 1023).
*
* \param res
*/
void setAnalogResolution(int res);
extern void analogReadResolution(int res);
/*
* \brief Set the resolution of analogWrite parameters. Default is 8 bits (range from 0 to 255).
*
* \param res
*/
extern void analogWriteResolution(int res);
extern void analogOutputInit( void ) ;

12
hardware/arduino/sam/variants/arduino_due_x/variant.h
View File

@ -174,11 +174,12 @@ static const uint8_t CANTX0 = 69;
/*
* PWM
*/
#define PWM_INTERFACE PWM
#define PWM_INTERFACE_ID ID_PWM
#define PWM_FREQUENCY 1000
#define PWM_MAX_DUTY_CYCLE 255
#define PWM_MIN_DUTY_CYCLE 0
#define PWM_INTERFACE PWM
#define PWM_INTERFACE_ID ID_PWM
#define PWM_FREQUENCY 1000
#define PWM_MAX_DUTY_CYCLE 255
#define PWM_MIN_DUTY_CYCLE 0
#define PWM_RESOLUTION 8
/*
* TC
@ -188,6 +189,7 @@ static const uint8_t CANTX0 = 69;
#define TC_FREQUENCY 1000
#define TC_MAX_DUTY_CYCLE 255
#define TC_MIN_DUTY_CYCLE 0
#define TC_RESOLUTION 8
#ifdef __cplusplus
}