djsundog/circuitpython
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Implement initial ADC support

Browse Source 
* Add simple ADC driver, with support for ADC1 and all channels.
* Export MicroPython ADC object with read_channel function.
* Add stm32f4xx_adc.c and adc.c to Makefile.
This commit is contained in:
mux 2014-01-14 19:57:51 +02:00
parent b4e374f138
commit 3591285091
4 changed files with 168 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
stm/Makefile
View File

@ -57,6 +57,7 @@ SRC_C = \
pybwlan.c \
i2c.c \
usrsw.c \
adc.c \
SRC_S = \
startup_stm32f40xx.s \
@ -100,6 +101,7 @@ SRC_STM = \
usbd_storage_msd.c \
stm324x7i_eval.c \
stm324x7i_eval_sdio_sd.c \
stm32f4xx_adc.c \
#SRC_STM_OTG = \
# usb_hcd.c \

163
stm/adc.c Normal file
View File

@ -0,0 +1,163 @@
#include <stdio.h>
#include <stm32f4xx_rcc.h>
#include <stm32f4xx_gpio.h>
#include <stm32f4xx_adc.h>
#include "misc.h"
#include "mpconfig.h"
#include "obj.h"
#include "adc.h"
/* ADC defintions */
#define ADCx (ADC1)
#define ADCx_CLK (RCC_APB2Periph_ADC1)
#define ADC_NUM_CHANNELS (16)
/* GPIO struct */
typedef struct {
GPIO_TypeDef* port;
uint32_t pin;
} gpio_t;
/* ADC GPIOs */
static gpio_t adc_gpio[] = {
{GPIOA, GPIO_Pin_0}, /* ADC123_IN0 */
{GPIOA, GPIO_Pin_1}, /* ADC123_IN1 */
{GPIOA, GPIO_Pin_2}, /* ADC123_IN2 */
{GPIOA, GPIO_Pin_3}, /* ADC123_IN3 */
{GPIOA, GPIO_Pin_4}, /* ADC12_IN4 */
{GPIOA, GPIO_Pin_5}, /* ADC12_IN5 */
{GPIOA, GPIO_Pin_6}, /* ADC12_IN6 */
{GPIOA, GPIO_Pin_7}, /* ADC12_IN7 */
{GPIOB, GPIO_Pin_0}, /* ADC12_IN8 */
{GPIOB, GPIO_Pin_1}, /* ADC12_IN9 */
{GPIOC, GPIO_Pin_0}, /* ADC123_IN10 */
{GPIOC, GPIO_Pin_1}, /* ADC123_IN11 */
{GPIOC, GPIO_Pin_2}, /* ADC123_IN12 */
{GPIOC, GPIO_Pin_3}, /* ADC123_IN13 */
{GPIOC, GPIO_Pin_4}, /* ADC12_IN14 */
{GPIOC, GPIO_Pin_5}, /* ADC12_IN15 */
};
void adc_init(uint32_t resolution) {
ADC_InitTypeDef ADC_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
ADC_CommonInitTypeDef ADC_CommonInitStructure;
/* Enable ADCx, DMA and GPIO clocks */
#if 0
/* GPIO clocks enabled in main */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA |
RCC_AHB1Periph_GPIOB |
RCC_AHB1Periph_GPIOC, ENABLE);
#endif
RCC_APB2PeriphClockCmd(ADCx_CLK, ENABLE);
/* ADC Common Init */
ADC_CommonInitStructure.ADC_Mode = ADC_Mode_Independent;
ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div2;
ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_Disabled;
ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_5Cycles;
ADC_CommonInit(&ADC_CommonInitStructure);
/* Configure ADC GPIOs */
for (int i=0; i<ADC_NUM_CHANNELS; i++) {
GPIO_InitStructure.GPIO_Pin = adc_gpio[i].pin;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(adc_gpio[i].port, &GPIO_InitStructure);
}
/* ADCx Init */
// ADC_DeInit();
ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
ADC_InitStructure.ADC_ScanConvMode = DISABLE;
ADC_InitStructure.ADC_ContinuousConvMode = DISABLE;
ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_T1_CC1;
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfConversion = 1;
ADC_Init(ADCx, &ADC_InitStructure);
/* Enable ADCx */
ADC_Cmd(ADCx, ENABLE);
}
uint32_t adc_read_channel(int channel)
{
int timeout = 10000;
if (channel > (ADC_NUM_CHANNELS-1)) {
return 0;
}
/* ADC regular channel config ADC/Channel/SEQ Rank/Sample time */
ADC_RegularChannelConfig(ADCx, channel, 1, ADC_SampleTime_3Cycles);
/* Start ADC single conversion */
ADC_SoftwareStartConv(ADCx);
/* Wait for conversion to be complete*/
while(!ADC_GetFlagStatus(ADCx, ADC_FLAG_EOC) && --timeout >0) {
}
/* ADC conversion timed out */
if (timeout == 0) {
return 0;
}
/* Return converted data */
return ADC_GetConversionValue(ADCx);
}
/******************************************************************************/
/* Micro Python bindings */
typedef struct _pyb_adc_obj_t {
mp_obj_base_t base;
int adc_id;
bool is_enabled;
} pyb_adc_obj_t;
static mp_obj_t adc_obj_read_channel(mp_obj_t self_in, mp_obj_t channel) {
mp_obj_t ret = mp_const_none;
pyb_adc_obj_t *self = self_in;
if (self->is_enabled) {
uint32_t chan = mp_obj_get_int(channel);
uint32_t data = adc_read_channel(chan);
ret = mp_obj_new_int(data);
}
return ret;
}
static void adc_obj_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in) {
pyb_adc_obj_t *self = self_in;
print(env, "<ADC %lu>", self->adc_id);
}
static MP_DEFINE_CONST_FUN_OBJ_2(adc_obj_read_channel_obj, adc_obj_read_channel);
static const mp_method_t adc_methods[] = {
{ "read_channel", &adc_obj_read_channel_obj},
{ NULL, NULL },
};
static const mp_obj_type_t adc_obj_type = {
{ &mp_const_type },
"ADC",
.print = adc_obj_print,
.methods = adc_methods,
};
mp_obj_t pyb_ADC(mp_obj_t resolution) {
/* init ADC */
adc_init(mp_obj_get_int(resolution));
pyb_adc_obj_t *o = m_new_obj(pyb_adc_obj_t);
o->base.type = &adc_obj_type;
o->adc_id = 1;
o->is_enabled = true;
return o;
}

1
stm/adc.h Normal file
View File

@ -0,0 +1 @@
mp_obj_t pyb_ADC(mp_obj_t resolution);

2
stm/main.c
View File

@ -40,6 +40,7 @@
#include "pybwlan.h"
#include "i2c.h"
#include "usrsw.h"
#include "adc.h"
int errno;
@ -839,6 +840,7 @@ soft_reset:
rt_store_attr(m, qstr_from_str_static("I2C"), rt_make_function_n(2, pyb_I2C));
rt_store_attr(m, qstr_from_str_static("gpio"), (mp_obj_t)&pyb_gpio_obj);
rt_store_attr(m, qstr_from_str_static("Usart"), rt_make_function_n(2, pyb_Usart));
rt_store_attr(m, qstr_from_str_static("ADC"), rt_make_function_n(1, pyb_ADC));
rt_store_name(qstr_from_str_static("pyb"), m);
rt_store_name(qstr_from_str_static("open"), rt_make_function_n(2, pyb_io_open));