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circuitpython/stmhal/adc.c
Damien George 38ae014e42 stmhal: Update ADC, DAC and I2C objects to use new buffer protocol. 
Main reason for expanding buffer protocol API was to support writes to a
buffer in ADC module (see read_timed).  With this change you can now
create an array of arbitrary type and ADC.read_timed will store into
that array in the correct format (byte, int, float).  I wonder though if
all these changes were really worth it to support just this function.
Hopefully this enhanced buffer protocol API (with typecode specified)
will be used elsewhere.
2014-04-18 23:28:56 +01:00

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#include <stdio.h>
#include <stm32f4xx_hal.h>
#include <string.h>
#include "misc.h"
#include "nlr.h"
#include "mpconfig.h"
#include "qstr.h"
#include "obj.h"
#include "runtime.h"
#include "binary.h"
#include "adc.h"
#include "pin.h"
#include "genhdr/pins.h"
#include "timer.h"
// Usage Model:
//
// adc = pyb.ADC(pin)
// val = adc.read()
//
// adc = pyb.ADCAll(resolution)
// val = adc.read_channel(channel)
// val = adc.read_core_temp()
// val = adc.read_core_vbat()
// val = adc.read_core_vref()
/* ADC defintions */
#define ADCx (ADC1)
#define ADCx_CLK_ENABLE __ADC1_CLK_ENABLE
#define ADC_NUM_CHANNELS (19)
#define ADC_NUM_GPIO_CHANNELS (16)
#if defined(STM32F405xx) || defined(STM32F415xx) || \
defined(STM32F407xx) || defined(STM32F417xx) || \
defined(STM32F401xC) || defined(STM32F401xE)
#define VBAT_DIV (2)
#elif defined(STM32F427xx) || defined(STM32F429xx) || \
defined(STM32F437xx) || defined(STM32F439xx)
#define VBAT_DIV (4)
#endif
/* Core temperature sensor definitions */
#define CORE_TEMP_V25 (943) /* (0.76v/3.3v)*(2^ADC resoultion) */
#define CORE_TEMP_AVG_SLOPE (3) /* (2.5mv/3.3v)*(2^ADC resoultion) */
typedef struct _pyb_obj_adc_t {
mp_obj_base_t base;
mp_obj_t pin_name;
int channel;
ADC_HandleTypeDef handle;
} pyb_obj_adc_t;
void adc_init_single(pyb_obj_adc_t *adc_obj) {
if (!IS_ADC_CHANNEL(adc_obj->channel)) {
return;
}
if (adc_obj->channel < ADC_NUM_GPIO_CHANNELS) {
// Channels 0-16 correspond to real pins. Configure the GPIO pin in
// ADC mode.
const pin_obj_t *pin = pin_adc1[adc_obj->channel];
GPIO_InitTypeDef GPIO_InitStructure;
GPIO_InitStructure.Pin = pin->pin_mask;
GPIO_InitStructure.Mode = GPIO_MODE_ANALOG;
GPIO_InitStructure.Pull = GPIO_NOPULL;
HAL_GPIO_Init(pin->gpio, &GPIO_InitStructure);
}
ADCx_CLK_ENABLE();
ADC_HandleTypeDef *adcHandle = &adc_obj->handle;
adcHandle->Instance = ADCx;
adcHandle->Init.ClockPrescaler = ADC_CLOCKPRESCALER_PCLK_DIV2;
adcHandle->Init.Resolution = ADC_RESOLUTION12b;
adcHandle->Init.ScanConvMode = DISABLE;
adcHandle->Init.ContinuousConvMode = DISABLE;
adcHandle->Init.DiscontinuousConvMode = DISABLE;
adcHandle->Init.NbrOfDiscConversion = 0;
adcHandle->Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
adcHandle->Init.ExternalTrigConv = ADC_EXTERNALTRIGCONV_T1_CC1;
adcHandle->Init.DataAlign = ADC_DATAALIGN_RIGHT;
adcHandle->Init.NbrOfConversion = 1;
adcHandle->Init.DMAContinuousRequests = DISABLE;
adcHandle->Init.EOCSelection = DISABLE;
HAL_ADC_Init(adcHandle);
ADC_ChannelConfTypeDef sConfig;
sConfig.Channel = adc_obj->channel;
sConfig.Rank = 1;
sConfig.SamplingTime = ADC_SAMPLETIME_15CYCLES;
sConfig.Offset = 0;
HAL_ADC_ConfigChannel(adcHandle, &sConfig);
}
uint32_t adc_read_channel(ADC_HandleTypeDef *adcHandle) {
uint32_t rawValue = 0;
HAL_ADC_Start(adcHandle);
if (HAL_ADC_PollForConversion(adcHandle, 10) == HAL_OK && HAL_ADC_GetState(adcHandle) == HAL_ADC_STATE_EOC_REG) {
rawValue = HAL_ADC_GetValue(adcHandle);
}
HAL_ADC_Stop(adcHandle);
return rawValue;
}
/******************************************************************************/
/* Micro Python bindings : adc object (single channel) */
STATIC void adc_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
pyb_obj_adc_t *self = self_in;
print(env, "<ADC on ");
mp_obj_print_helper(print, env, self->pin_name, PRINT_STR);
print(env, " channel=%lu>", self->channel);
}
STATIC mp_obj_t adc_make_new(mp_obj_t type_in, uint n_args, uint n_kw, const mp_obj_t *args) {
// check number of arguments
mp_check_nargs(n_args, 1, 1, n_kw, false);
// 1st argument is the pin name
mp_obj_t pin_obj = args[0];
uint32_t channel;
if (MP_OBJ_IS_INT(pin_obj)) {
channel = mp_obj_get_int(pin_obj);
} else {
const pin_obj_t *pin = pin_find(pin_obj);
if ((pin->adc_num & PIN_ADC1) == 0) {
// No ADC1 function on that pin
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "pin %s does not have ADC capabilities", pin->name));
}
channel = pin->adc_channel;
}
if (!IS_ADC_CHANNEL(channel)) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "not a valid ADC Channel: %d", channel));
}
if (pin_adc1[channel] == NULL) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "channel %d not available on this board", channel));
}
pyb_obj_adc_t *o = m_new_obj(pyb_obj_adc_t);
memset(o, 0, sizeof(*o));
o->base.type = &pyb_adc_type;
o->pin_name = pin_obj;
o->channel = channel;
adc_init_single(o);
return o;
}
STATIC mp_obj_t adc_read(mp_obj_t self_in) {
pyb_obj_adc_t *self = self_in;
uint32_t data = adc_read_channel(&self->handle);
return mp_obj_new_int(data);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(adc_read_obj, adc_read);
STATIC mp_obj_t adc_read_timed(mp_obj_t self_in, mp_obj_t buf_in, mp_obj_t freq_in) {
pyb_obj_adc_t *self = self_in;
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(buf_in, &bufinfo, MP_BUFFER_WRITE);
int typesize = mp_binary_get_size(bufinfo.typecode);
// Init TIM6 at the required frequency (in Hz)
timer_tim6_init(mp_obj_get_int(freq_in));
// Start timer
HAL_TIM_Base_Start(&TIM6_Handle);
// This uses the timer in polling mode to do the sampling
// We could use DMA, but then we can't convert the values correctly for the buffer
for (uint index = 0; index < bufinfo.len; index++) {
// Wait for the timer to trigger
while (__HAL_TIM_GET_FLAG(&TIM6_Handle, TIM_FLAG_UPDATE) == RESET) {
}
__HAL_TIM_CLEAR_FLAG(&TIM6_Handle, TIM_FLAG_UPDATE);
uint value = adc_read_channel(&self->handle);
if (typesize == 1) {
value >>= 4;
}
mp_binary_set_val_array_from_int(bufinfo.typecode, bufinfo.buf, index, value);
}
// Stop timer
HAL_TIM_Base_Stop(&TIM6_Handle);
return mp_obj_new_int(bufinfo.len);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_3(adc_read_timed_obj, adc_read_timed);
STATIC const mp_map_elem_t adc_locals_dict_table[] = {
{ MP_OBJ_NEW_QSTR(MP_QSTR_read), (mp_obj_t)&adc_read_obj},
{ MP_OBJ_NEW_QSTR(MP_QSTR_read_timed), (mp_obj_t)&adc_read_timed_obj},
};
STATIC MP_DEFINE_CONST_DICT(adc_locals_dict, adc_locals_dict_table);
const mp_obj_type_t pyb_adc_type = {
{ &mp_type_type },
.name = MP_QSTR_ADC,
.print = adc_print,
.make_new = adc_make_new,
.locals_dict = (mp_obj_t)&adc_locals_dict,
};
/******************************************************************************/
/* adc all object */
typedef struct _pyb_adc_all_obj_t {
mp_obj_base_t base;
ADC_HandleTypeDef handle;
} pyb_adc_all_obj_t;
void adc_init_all(pyb_adc_all_obj_t *adc_all, uint32_t resolution) {
switch (resolution) {
case 6: resolution = ADC_RESOLUTION6b; break;
case 8: resolution = ADC_RESOLUTION8b; break;
case 10: resolution = ADC_RESOLUTION10b; break;
case 12: resolution = ADC_RESOLUTION12b; break;
default:
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError,
"resolution %d not supported", resolution));
}
for (uint32_t channel = 0; channel < ADC_NUM_GPIO_CHANNELS; channel++) {
// Channels 0-16 correspond to real pins. Configure the GPIO pin in
// ADC mode.
const pin_obj_t *pin = pin_adc1[channel];
GPIO_InitTypeDef GPIO_InitStructure;
GPIO_InitStructure.Pin = pin->pin_mask;
GPIO_InitStructure.Mode = GPIO_MODE_ANALOG;
GPIO_InitStructure.Pull = GPIO_NOPULL;
HAL_GPIO_Init(pin->gpio, &GPIO_InitStructure);
}
ADCx_CLK_ENABLE();
ADC_HandleTypeDef *adcHandle = &adc_all->handle;
adcHandle->Instance = ADCx;
adcHandle->Init.ClockPrescaler = ADC_CLOCKPRESCALER_PCLK_DIV2;
adcHandle->Init.Resolution = resolution;
adcHandle->Init.ScanConvMode = DISABLE;
adcHandle->Init.ContinuousConvMode = DISABLE;
adcHandle->Init.DiscontinuousConvMode = DISABLE;
adcHandle->Init.NbrOfDiscConversion = 0;
adcHandle->Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
adcHandle->Init.ExternalTrigConv = ADC_EXTERNALTRIGCONV_T1_CC1;
adcHandle->Init.DataAlign = ADC_DATAALIGN_RIGHT;
adcHandle->Init.NbrOfConversion = 1;
adcHandle->Init.DMAContinuousRequests = DISABLE;
adcHandle->Init.EOCSelection = DISABLE;
HAL_ADC_Init(adcHandle);
}
uint32_t adc_config_and_read_channel(ADC_HandleTypeDef *adcHandle, uint32_t channel) {
ADC_ChannelConfTypeDef sConfig;
sConfig.Channel = channel;
sConfig.Rank = 1;
sConfig.SamplingTime = ADC_SAMPLETIME_15CYCLES;
sConfig.Offset = 0;
HAL_ADC_ConfigChannel(adcHandle, &sConfig);
return adc_read_channel(adcHandle);
}
int adc_get_resolution(ADC_HandleTypeDef *adcHandle) {
uint32_t res_reg = __HAL_ADC_GET_RESOLUTION(adcHandle);
switch (res_reg) {
case ADC_RESOLUTION6b: return 6;
case ADC_RESOLUTION8b: return 8;
case ADC_RESOLUTION10b: return 10;
}
return 12;
}
int adc_read_core_temp(ADC_HandleTypeDef *adcHandle) {
int32_t raw_value = adc_config_and_read_channel(adcHandle, ADC_CHANNEL_TEMPSENSOR);
// Note: constants assume 12-bit resolution, so we scale the raw value to
// be 12-bits.
raw_value <<= (12 - adc_get_resolution(adcHandle));
return ((raw_value - CORE_TEMP_V25) / CORE_TEMP_AVG_SLOPE) + 25;
}
float adc_read_core_vbat(ADC_HandleTypeDef *adcHandle) {
uint32_t raw_value = adc_config_and_read_channel(adcHandle, ADC_CHANNEL_VBAT);
// Note: constants assume 12-bit resolution, so we scale the raw value to
// be 12-bits.
raw_value <<= (12 - adc_get_resolution(adcHandle));
return raw_value * VBAT_DIV / 4096.0f * 3.3f;
}
float adc_read_core_vref(ADC_HandleTypeDef *adcHandle) {
uint32_t raw_value = adc_config_and_read_channel(adcHandle, ADC_CHANNEL_VREFINT);
// Note: constants assume 12-bit resolution, so we scale the raw value to
// be 12-bits.
raw_value <<= (12 - adc_get_resolution(adcHandle));
return raw_value * VBAT_DIV / 4096.0f * 3.3f;
}
/******************************************************************************/
/* Micro Python bindings : adc_all object */
STATIC mp_obj_t adc_all_make_new(mp_obj_t type_in, uint n_args, uint n_kw, const mp_obj_t *args) {
// check number of arguments
mp_check_nargs(n_args, 1, 1, n_kw, false);
// make ADCAll object
pyb_adc_all_obj_t *o = m_new_obj(pyb_adc_all_obj_t);
o->base.type = &pyb_adc_all_type;
adc_init_all(o, mp_obj_get_int(args[0])); // args[0] is the resolution
return o;
}
STATIC mp_obj_t adc_all_read_channel(mp_obj_t self_in, mp_obj_t channel) {
pyb_adc_all_obj_t *self = self_in;
uint32_t chan = mp_obj_get_int(channel);
uint32_t data = adc_config_and_read_channel(&self->handle, chan);
return mp_obj_new_int(data);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(adc_all_read_channel_obj, adc_all_read_channel);
STATIC mp_obj_t adc_all_read_core_temp(mp_obj_t self_in) {
pyb_adc_all_obj_t *self = self_in;
int data = adc_read_core_temp(&self->handle);
return mp_obj_new_int(data);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(adc_all_read_core_temp_obj, adc_all_read_core_temp);
STATIC mp_obj_t adc_all_read_core_vbat(mp_obj_t self_in) {
pyb_adc_all_obj_t *self = self_in;
float data = adc_read_core_vbat(&self->handle);
return mp_obj_new_float(data);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(adc_all_read_core_vbat_obj, adc_all_read_core_vbat);
STATIC mp_obj_t adc_all_read_core_vref(mp_obj_t self_in) {
pyb_adc_all_obj_t *self = self_in;
float data = adc_read_core_vref(&self->handle);
return mp_obj_new_float(data);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(adc_all_read_core_vref_obj, adc_all_read_core_vref);
STATIC const mp_map_elem_t adc_all_locals_dict_table[] = {
{ MP_OBJ_NEW_QSTR(MP_QSTR_read_channel), (mp_obj_t)&adc_all_read_channel_obj},
{ MP_OBJ_NEW_QSTR(MP_QSTR_read_core_temp), (mp_obj_t)&adc_all_read_core_temp_obj},
{ MP_OBJ_NEW_QSTR(MP_QSTR_read_core_vbat), (mp_obj_t)&adc_all_read_core_vbat_obj},
{ MP_OBJ_NEW_QSTR(MP_QSTR_read_core_vref), (mp_obj_t)&adc_all_read_core_vref_obj},
};
STATIC MP_DEFINE_CONST_DICT(adc_all_locals_dict, adc_all_locals_dict_table);
const mp_obj_type_t pyb_adc_all_type = {
{ &mp_type_type },
.name = MP_QSTR_ADCAll,
.make_new = adc_all_make_new,
.locals_dict = (mp_obj_t)&adc_all_locals_dict,
};
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