129 lines
3.2 KiB
C
129 lines
3.2 KiB
C
/*
|
|
* Copyright (c) 2016 Intel Corporation
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*/
|
|
|
|
#define DT_DRV_COMPAT seeed_grove_light
|
|
|
|
#include <zephyr/drivers/adc.h>
|
|
#include <zephyr/device.h>
|
|
#include <zephyr/devicetree.h>
|
|
#include <math.h>
|
|
#include <zephyr/drivers/sensor.h>
|
|
#include <zephyr/kernel.h>
|
|
#include <zephyr/logging/log.h>
|
|
|
|
LOG_MODULE_REGISTER(grove_light, CONFIG_SENSOR_LOG_LEVEL);
|
|
|
|
/* The effect of gain and reference voltage must cancel. */
|
|
#ifdef CONFIG_ADC_NRFX_SAADC
|
|
#define GROVE_GAIN ADC_GAIN_1_4
|
|
#define GROVE_REF ADC_REF_VDD_1_4
|
|
#define GROVE_RESOLUTION 12
|
|
#else
|
|
#define GROVE_GAIN ADC_GAIN_1
|
|
#define GROVE_REF ADC_REF_VDD_1
|
|
#define GROVE_RESOLUTION 12
|
|
#endif
|
|
|
|
|
|
struct gls_data {
|
|
const struct device *adc;
|
|
struct adc_channel_cfg ch_cfg;
|
|
uint16_t raw;
|
|
};
|
|
|
|
struct gls_config {
|
|
const struct device *adc;
|
|
uint8_t adc_channel;
|
|
};
|
|
|
|
static struct adc_sequence_options options = {
|
|
.interval_us = 12,
|
|
.extra_samplings = 0,
|
|
};
|
|
|
|
static struct adc_sequence adc_table = {
|
|
.options = &options,
|
|
};
|
|
|
|
static int gls_sample_fetch(const struct device *dev,
|
|
enum sensor_channel chan)
|
|
{
|
|
const struct gls_config *cfg = dev->config;
|
|
|
|
return adc_read(cfg->adc, &adc_table);
|
|
}
|
|
|
|
static int gls_channel_get(const struct device *dev,
|
|
enum sensor_channel chan,
|
|
struct sensor_value *val)
|
|
{
|
|
struct gls_data *drv_data = dev->data;
|
|
uint16_t analog_val = drv_data->raw;
|
|
double ldr_val, dval;
|
|
|
|
/*
|
|
* The formula for converting the analog value to lux is taken from
|
|
* the UPM project:
|
|
* https://github.com/intel-iot-devkit/upm/blob/master/src/grove/grove.cxx#L161
|
|
*/
|
|
ldr_val = (BIT(GROVE_RESOLUTION) - 1.0 - analog_val) * 10.0 / analog_val;
|
|
dval = 10000.0 / pow(ldr_val * 15.0, 4.0/3.0);
|
|
|
|
val->val1 = (int32_t)dval;
|
|
val->val2 = ((int32_t)(dval * 1000000)) % 1000000;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct sensor_driver_api gls_api = {
|
|
.sample_fetch = &gls_sample_fetch,
|
|
.channel_get = &gls_channel_get,
|
|
};
|
|
|
|
static int gls_init(const struct device *dev)
|
|
{
|
|
struct gls_data *drv_data = dev->data;
|
|
const struct gls_config *cfg = dev->config;
|
|
|
|
if (!device_is_ready(cfg->adc)) {
|
|
LOG_ERR("ADC device is not ready.");
|
|
return -EINVAL;
|
|
}
|
|
|
|
/*Change following parameters according to board if necessary*/
|
|
drv_data->ch_cfg = (struct adc_channel_cfg){
|
|
.gain = GROVE_GAIN,
|
|
.reference = GROVE_REF,
|
|
.acquisition_time = ADC_ACQ_TIME_DEFAULT,
|
|
.channel_id = cfg->adc_channel,
|
|
#ifdef CONFIG_ADC_NRFX_SAADC
|
|
.input_positive = SAADC_CH_PSELP_PSELP_AnalogInput0 + cfg->adc_channel,
|
|
#endif
|
|
};
|
|
adc_table.buffer = &drv_data->raw;
|
|
adc_table.buffer_size = sizeof(drv_data->raw);
|
|
adc_table.resolution = GROVE_RESOLUTION;
|
|
adc_table.channels = BIT(cfg->adc_channel);
|
|
|
|
adc_channel_setup(cfg->adc, &drv_data->ch_cfg);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#define GLS_DEFINE(inst) \
|
|
static struct gls_data gls_data_##inst; \
|
|
\
|
|
static const struct gls_config gls_cfg_##inst = { \
|
|
.adc = DEVICE_DT_GET(DT_INST_IO_CHANNELS_CTLR(inst)), \
|
|
.adc_channel = DT_INST_IO_CHANNELS_INPUT(inst), \
|
|
}; \
|
|
\
|
|
SENSOR_DEVICE_DT_INST_DEFINE(inst, &gls_init, NULL, \
|
|
&gls_data_##inst, &gls_cfg_##inst, POST_KERNEL, \
|
|
CONFIG_SENSOR_INIT_PRIORITY, &gls_api); \
|
|
|
|
DT_INST_FOREACH_STATUS_OKAY(GLS_DEFINE)
|