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Basic DAC Driver, implementation on stm32f4discovery

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dev/timer
Simon Brummer 8 years ago
parent f9c7e21e4e
commit 5a4b966d9c
4 changed files with 342 additions and 5 deletions
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3
boards/stm32f4discovery/Makefile.features
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@ -1,2 +1 @@
FEATURES_PROVIDED += periph_gpio periph_spi periph_i2c periph_pwm periph_random periph_adc cpp
FEATURES_PROVIDED += periph_gpio periph_spi periph_i2c periph_pwm periph_random periph_adc periph_dac cpp

26
boards/stm32f4discovery/include/periph_conf.h
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@ -132,21 +132,41 @@ extern "C" {
#define ADC_0_CH1 4
#define ADC_0_CH1_PIN 4
/* ADC 0 configuration */
/* ADC 1 configuration */
#define ADC_1_DEV ADC2
#define ADC_1_CHANNELS 2
#define ADC_1_CLKEN() (RCC->APB2ENR |= RCC_APB2ENR_ADC2EN)
#define ADC_1_CLKDIS() (RCC->APB2ENR &= ~(RCC_APB2ENR_ADC2EN))
#define ADC_1_PORT GPIOC
#define ADC_1_PORT_CLKEN() (RCC->AHB1ENR |= RCC_AHB1ENR_GPIOCEN)
/* ADC 0 channel 0 pin config */
/* ADC 1 channel 0 pin config */
#define ADC_1_CH0 11
#define ADC_1_CH0_PIN 1
/* ADC 0 channel 1 pin config */
/* ADC 1 channel 1 pin config */
#define ADC_1_CH1 12
#define ADC_1_CH1_PIN 2
/** @} */
/**
* @name DAC configuration
* @{
*/
#define DAC_NUMOF (1U)
#define DAC_0_EN 1
#define DAC_MAX_CHANNELS 2
/* DAC 0 configuration */
#define DAC_0_DEV DAC
#define DAC_0_CHANNELS 2
#define DAC_0_CLKEN() (RCC->APB1ENR |= (RCC_APB1ENR_DACEN))
#define DAC_0_CLKDIS() (RCC->APB1ENR &= ~(RCC_APB1ENR_DACEN))
#define DAC_0_PORT GPIOA
#define DAC_0_PORT_CLKEN() (RCC->AHB1ENR |= RCC_AHB1ENR_GPIOAEN)
/* DAC 0 channel config */
#define DAC_0_CH0_PIN 4
#define DAC_0_CH1_PIN 5
/**
* @name PWM configuration
* @{

166
cpu/stm32f4/periph/dac.c
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@ -0,0 +1,166 @@
/*
* Copyright (C) 2014 Simon Brummer
*
* This file is subject to the terms and conditions of the GNU Lesser General
* Public License v2.1. See the file LICENSE in the top level directory for more
* details.
*/
/**
* @ingroup cpu_stm32f4
* @{
*
* @file
* @brief Low-level DAC driver implementation
*
* @author Simon Brummer<simon.brummer@haw-hamburg.de>
*
* @}
*/
#include "cpu.h"
#include "periph/dac.h"
#include "periph_conf.h"
/* guard in case that no DAC device is defined */
#if DAC_NUMOF
#define DAC_MAX_12BIT 0x0fff
typedef struct {
uint8_t shift_mod;
} dac_config_t;
dac_config_t dac_config[DAC_NUMOF];
int8_t dac_init(dac_t dev, dac_precision_t precision)
{
DAC_TypeDef *dac = 0;
dac_poweron(dev);
switch (dev) {
#if DAC_0_EN
case DAC_0:
dac = DAC_0_DEV;
DAC_0_PORT_CLKEN();
/* Set Mode to analoge out, disable Pullup Pulldown Resistors for both channels */
DAC_0_PORT->MODER |= (3 << (DAC_0_CH0_PIN * 2) | 3 << (DAC_0_CH1_PIN * 2));
DAC_0_PORT->PUPDR &= ~(3 << (DAC_0_CH0_PIN * 2) | 3 << (DAC_0_CH1_PIN * 2));
break;
#endif
default:
/* Unknown Device */
return -1;
}
/* Select Shift value to normalize given Value */
switch(precision) {
case DAC_RES_6BIT:
dac_config[dev].shift_mod = 0x06; /* 2^6 << 6 = 2^12 */
break;
case DAC_RES_8BIT:
dac_config[dev].shift_mod = 0x04; /* 2^8 << 4 = 2^12 */
break;
case DAC_RES_10BIT:
dac_config[dev].shift_mod = 0x02; /* 2^10 << 2 = 2^12 */
break;
case DAC_RES_12BIT:
dac_config[dev].shift_mod = 0x00; /* 2^12 << 0 = 2^12 */
break;
/* Not Supported Resolutions */
case DAC_RES_14BIT:
case DAC_RES_16BIT:
default:
dac_poweroff(dev);
return -2;
break;
}
/* Enable Channels, Clear Output */
dac->CR = 0;
dac->CR |= (DAC_CR_EN1 | DAC_CR_EN2);
dac->DHR12R1 = 0;
dac->DHR12R2 = 0;
return 0;
}
int8_t dac_write(dac_t dev, uint8_t channel, uint16_t value)
{
DAC_TypeDef* __attribute__((unused)) dac = 0;
uint16_t __attribute__((unused)) val = value << dac_config[dev].shift_mod;
switch(dev){
#if DAC_0_EN
case DAC_0:
dac = DAC_0_DEV;
if( DAC_MAX_12BIT < val ){
/* Value out of Range */
return -3;
}
switch(channel){
case 0:
dac->DHR12R1 = val;
break;
case 1:
dac->DHR12R2 = val;
break;
/* Invalid Channel */
default:
return -2;
}
break;
#endif
/* Unknown Device */
default:
return -1;
}
return 0;
}
int8_t dac_poweron(dac_t dev)
{
switch (dev){
#if DAC_0_EN
case DAC_0:
DAC_0_CLKEN();
break;
#endif
default:
/* Unknown Device */
return -1;
}
return 0;
}
int8_t dac_poweroff(dac_t dev)
{
switch (dev) {
#if DAC_0_EN
case DAC_0:
DAC_0_CLKDIS();
break;
#endif
default:
/* Unknown Device */
return -1;
}
return 0;
}
uint16_t dac_map(dac_t dev, int value, int min, int max)
{
return dac_mapf(dev, (int) value, (int) min, (int) max);
}
uint16_t dac_mapf(dac_t dev, float value, float min, float max)
{
uint16_t val_12_bit = ((value - min) * DAC_MAX_12BIT)/(max-min);
return val_12_bit >> dac_config[dev].shift_mod;
}
#undef DAC_MAX_12BIT
#endif /* DAC_NUMOF */

152
drivers/include/periph/dac.h
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/*
* Copyright (C) 2014 Simon Brummer
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @defgroup driver_periph_dac DAC
* @ingroup driver_periph
* @brief Low-level DAC peripheral driver
* @{
*
* @file
* @brief Low-level DAC peripheral driver interface definitions
*
* @author Simon Brummer <simon.brummer@haw-hamburg.de>
*/
#ifndef __DAC_H
#define __DAC_H
#include <stdint.h>
#include "periph_conf.h"
#ifdef __cplusplus
extern "C" {
#endif
/* guard file in case no ADC device is defined */
#if DAC_NUMOF
/**
* @brief Definition avialable DAC devices
*
* Each DAC device is based on a hardware DAC which can have one or more
* independet channels.
*/
typedef enum {
#if DAC_0_EN
DAC_0 = 0, /**< DAC device 0 */
#endif
#if DAC_1_EN
DAC_1 = 1, /**< DAC device 1 */
#endif
#if DAC_2_EN
DAC_2 = 2, /**< DAC device 2 */
#endif
#if DAC_3_EN
DAC_3 = 3, /**< DAC device 3 */
#endif
} dac_t;
/**
* @breif Possilbe DAC precision settings
*/
typedef enum {
DAC_RES_6BIT = 0, /**< DAC precision: 6 bit */
DAC_RES_8BIT, /**< DAC precision: 8 bit */
DAC_RES_10BIT, /**< DAC precision: 10 bit */
DAC_RES_12BIT, /**< DAC precision: 12 bit */
DAC_RES_14BIT, /**< DAC precision: 14 bit */
DAC_RES_16BIT, /**< DAC precision: 16 bit */
} dac_precision_t;
/**
* @brief Initialization of a given DAC device
*
* The DAC will be initialized with all possilble channels active.
* On each channel will be initialized with a Zero on it.
*
* @param[in] dev the device to initialize
* @param[in] precision the precision to use for conversion
*
* @return 0 on success
* @return -1 on unknown DAC Device
* @return -2 on precision not available
*/
int8_t dac_init(dac_t dev, dac_precision_t precision);
/**
* @brief Write a value onto DAC Device on a given Channel.
*
* @param[in] dev the DAC device to use
* @param[in] channel the channel used for Digital/Analoge conversion
* @param[in] value the value to write onto DAC.
*
* @return 0 on success
* @return -1 on unknown DAC Device
* @return -2 on invalid channel
* @return -3 if value is out of range.
*/
int8_t dac_write(dac_t dev, uint8_t channel, uint16_t value);
/**
* @brief Enable power for the given DAC Device
*
* @param[in] dev the DAC device to power up.
*
* @return 0 on success
* @return -1 on unknown DAC Device
*/
int8_t dac_poweron(dac_t dev);
/**
* @brief Disable power for the given DAC Device
*
* @param[in] dev the DAC device to power down
*
* @return 0 on success
* @return -1 on unknown DAC Device
*/
int8_t dac_poweroff(dac_t dev);
/**
* @brief Helper function to map a given integer range to a valid DAC value.
*
* This function is useful for converting ranges of values to a valid DAC output value.
*
* The min value is assumed to be smaller than max value and value is assumed
* to be between min and max.
*
* @param[in] dev the DAC Device to read precision value from
* @param[in] value the value to map onto min and max
* @param[in] min the lower bound of the target interval
* @param[in] max the upper bound of the target interval
*
* @return the mapped value, in valid DAC range
*/
uint16_t dac_map(dac_t dev, int value, int min, int max);
/**
* @brief Helper function to map a given float value range to a valid DAC value.
*
* @see dac_map
*
* @param[in] dev the DAC Device to read precision value from
* @param[in] value the value to map onto min and max
* @param[in] min the lower bound of the target interval
* @param[in] max the upper bound of the target interval
*
* @return the mapped value, in valid DAC range
*/
uint16_t dac_mapf(dac_t dev, float value, float min, float max);
#endif/* DAC_NUMOF */
#ifdef __cplusplus
}
#endif
#endif /* __DAC_H */
/** @} */
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