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cpu/nrf51: adapted ADC driver to interface changes

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This commit is contained in:
Hauke Petersen 2016-01-26 23:43:37 +01:00
parent e25d1c9dc5
commit 843c456f4b
2 changed files with 69 additions and 95 deletions
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149
cpu/nrf51/periph/adc.c
View File

@ -1,10 +1,10 @@
/*
* Copyright (C) 2014 Freie Universität Berlin
* Copyright (C) 2015 Ludwig Knüpfer
* Copyright (C) 2014-2016 Freie Universität Berlin
* 2015 Ludwig Knüpfer
*
* 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.
* 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.
*/
/**
@ -12,7 +12,7 @@
* @{
*
* @file
* @brief Low-level UART driver implementation
* @brief Low-level ADC driver implementation
*
* @author Hauke Petersen <hauke.petersen@fu-berlin.de>
* @author Ludwig Knüpfer <ludwig.knuepfer@fu-berlin.de>
@ -21,114 +21,73 @@
*/
#include "cpu.h"
#include "mutex.h"
#include "periph/adc.h"
#include "periph_conf.h"
/* guard file in case no ADC device is defined */
#if ADC_NUMOF
/**
* @brief Load the ADC configuration
* @{
*/
#ifdef ADC_CONFIG
static const uint8_t adc_config[] = ADC_CONFIG;
#else
static const uint8_t adc_config[] = {};
#endif
/* save the maximum value configured for the ADC */
int adc_max_value;
/**
* @brief Lock to prevent concurrency issues when used from different threads
*/
static mutex_t lock;
int adc_init(adc_t dev, adc_precision_t precision)
static inline void prep(void)
{
/* the NRF51822 only supports one ADC... */
if (dev != ADC_0) {
return -2;
}
/* power on ADC */
mutex_lock(&lock);
NRF_ADC->POWER = 1;
NRF_ADC->ENABLE = 1;
}
/* disable ADC interrupts */
NRF_ADC->INTENSET = (ADC_INTENSET_END_Disabled << ADC_INTENSET_END_Pos);
static inline void done(void)
{
NRF_ADC->ENABLE = 0;
NRF_ADC->POWER = 0;
mutex_unlock(&lock);
}
/* configure ADC, set precision, internal reference to VBG */
switch (precision) {
case ADC_RES_8BIT:
adc_max_value = 255;
NRF_ADC->CONFIG = (ADC_CONFIG_RES_8bit << ADC_CONFIG_RES_Pos);
break;
case ADC_RES_10BIT:
adc_max_value = 1023;
NRF_ADC->CONFIG = (ADC_CONFIG_RES_10bit << ADC_CONFIG_RES_Pos);
break;
default:
NRF_ADC->POWER = 0;
return -1;
int adc_init(adc_t line)
{
if (line >= ADC_NUMOF) {
return -1;
}
/* select the reference voltage / prescaler */
NRF_ADC->CONFIG |= (ADC_CONFIG_EXTREFSEL_None << ADC_CONFIG_EXTREFSEL_Pos);
NRF_ADC->CONFIG |= (ADC_CONFIG_REFSEL_VBG << ADC_CONFIG_REFSEL_Pos);
NRF_ADC->CONFIG |= (ADC_CONFIG_INPSEL_AnalogInputOneThirdPrescaling << ADC_CONFIG_INPSEL_Pos);
/* enable the ADC */
NRF_ADC->ENABLE = (ADC_ENABLE_ENABLE_Enabled << ADC_ENABLE_ENABLE_Pos);
return 0;
}
int adc_sample(adc_t dev, int channel)
int adc_sample(adc_t line, adc_res_t res)
{
if (dev != ADC_0) {
return -2;
int val;
/* check if resolution is valid */
if (res > 2) {
return -1;
}
/* set channel */
NRF_ADC->CONFIG &= ~(ADC_CONFIG_PSEL_Msk);
NRF_ADC->CONFIG |= (ADC_CONFIG_PSEL_Disabled << ADC_CONFIG_PSEL_Pos);
switch (channel) {
case 0:
NRF_ADC->CONFIG |= (ADC_0_CH0 << ADC_CONFIG_PSEL_Pos);
break;
case 1:
NRF_ADC->CONFIG |= (ADC_0_CH1 << ADC_CONFIG_PSEL_Pos);
break;
case 2:
NRF_ADC->CONFIG |= (ADC_0_CH2 << ADC_CONFIG_PSEL_Pos);
break;
case 3:
NRF_ADC->CONFIG |= (ADC_0_CH3 << ADC_CONFIG_PSEL_Pos);
break;
default:
return -1;
}
/* prepare device */
prep();
/* set resolution, line, and use 1/3 input and ref voltage scaling */
NRF_ADC->CONFIG = ((ADC_CONFIG_REFSEL_SupplyOneThirdPrescaling << 5) |
(ADC_CONFIG_INPSEL_AnalogInputOneThirdPrescaling << 2) |
(1 << (adc_config[line] + 8)) |
res);
/* start conversion */
NRF_ADC->TASKS_START = 1;
/* wait for conversion to be complete */
while (((NRF_ADC->BUSY & ADC_BUSY_BUSY_Msk) >> ADC_BUSY_BUSY_Pos) == ADC_BUSY_BUSY_Busy) {}
NRF_ADC->EVENTS_END = 1;
while (NRF_ADC->BUSY == 1) {}
/* get result */
val = (int)NRF_ADC->RESULT;
/* return result */
return (int)NRF_ADC->RESULT;
/* free device */
done();
return val;
}
void adc_poweron(adc_t dev)
{
if (dev == ADC_0) {
NRF_ADC->POWER = 1;
}
}
void adc_poweroff(adc_t dev)
{
if (dev == ADC_0) {
NRF_ADC->POWER = 0;
}
}
int adc_map(adc_t dev, int value, int min, int max)
{
return (int)adc_mapf(dev, value, (float)min, (float)max);
}
float adc_mapf(adc_t dev, int value, float min, float max)
{
(void) dev;
return ((max - min) / ((float)adc_max_value)) * value;
}
#endif /* ADC_NUMOF */

15
cpu/nrf5x_common/include/periph_cpu.h
View File

@ -77,6 +77,21 @@ typedef enum {
} gpio_flank_t;
/** @} */
/**
* @brief Override ADC resolution values
* @{
*/
#define HAVE_ADC_RES_T
typedef enum {
ADC_RES_6BIT = 0xf0, /**< ADC resolution: 6 bit */
ADC_RES_8BIT = 0x00, /**< ADC resolution: 8 bit */
ADC_RES_10BIT = 0x02, /**< ADC resolution: 10 bit */
ADC_RES_12BIT = 0xf1, /**< ADC resolution: 12 bit */
ADC_RES_14BIT = 0xf2, /**< ADC resolution: 14 bit */
ADC_RES_16BIT = 0xf3 /**< ADC resolution: 16 bit */
} adc_res_t;
/** @} */
/**
* @brief Timer configuration options
*/