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stmhal: Add ADC function to read data at a given frequency.

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Reads ADC values into a bytearray (or similar) at a fixed rate.  Needs a
better name and improved API.  Also fix up DAC dma function (which also
needs a better name and API).
This commit is contained in:
Damien George 2014-04-15 19:52:56 +01:00
parent e95da5b784
commit 4d7f4eb6a9
5 changed files with 82 additions and 22 deletions
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32
stmhal/adc.c
View File

@ -11,6 +11,7 @@
#include "adc.h"
#include "pin.h"
#include "build/pins.h"
#include "timer.h"
// Usage Model:
//
@ -162,8 +163,39 @@ STATIC mp_obj_t adc_read(mp_obj_t self_in) {
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;
buffer_info_t bufinfo;
mp_get_buffer_raise(buf_in, &bufinfo);
// 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
// TODO use DMA
for (uint i = 0; i < bufinfo.len; i++) {
// 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);
((byte*)bufinfo.buf)[i] = adc_read_channel(&self->handle) >> 4;
}
// 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);

42
stmhal/dac.c
View File

@ -10,9 +10,9 @@
#include "parse.h"
#include "obj.h"
#include "runtime.h"
#include "timer.h"
#include "dac.h"
TIM_HandleTypeDef TIM6_Handle;
STATIC DAC_HandleTypeDef DAC_Handle;
void dac_init(void) {
@ -22,19 +22,8 @@ void dac_init(void) {
}
STATIC void TIM6_Config(uint freq) {
// TIM6 clock enable
__TIM6_CLK_ENABLE();
// Compute the prescaler value so TIM6 triggers at freq-Hz
uint16_t period = (uint16_t) ((SystemCoreClock / 2) / freq) - 1;
// time base clock configuration
TIM6_Handle.Instance = TIM6;
TIM6_Handle.Init.Period = period;
TIM6_Handle.Init.Prescaler = 0; // timer runs at SystemCoreClock / 2
TIM6_Handle.Init.ClockDivision = 0; // unused for TIM6
TIM6_Handle.Init.CounterMode = TIM_COUNTERMODE_UP; // unused for TIM6
HAL_TIM_Base_Init(&TIM6_Handle);
// Init TIM6 at the required frequency (in Hz)
timer_tim6_init(freq);
// TIM6 TRGO selection
TIM_MasterConfigTypeDef config;
@ -203,17 +192,14 @@ mp_obj_t pyb_dac_dma(uint n_args, const mp_obj_t *args, mp_map_t *kw_args) {
DAC_Init(self->dac_channel, &DAC_InitStructure);
*/
if (self->state != 3) {
DAC_ChannelConfTypeDef config;
config.DAC_Trigger = DAC_TRIGGER_T6_TRGO;
config.DAC_OutputBuffer = DAC_OUTPUTBUFFER_ENABLE;
HAL_DAC_ConfigChannel(&DAC_Handle, &config, self->dac_channel);
self->state = 3;
}
// DMA1_Stream[67] channel7 configuration
DMA_HandleTypeDef DMA_Handle;
DMA_Handle.Instance = self->dma_stream;
// Need to deinit DMA first
DMA_Handle.State = HAL_DMA_STATE_READY;
HAL_DMA_DeInit(&DMA_Handle);
DMA_Handle.Init.Channel = DMA_CHANNEL_7;
DMA_Handle.Init.Direction = DMA_MEMORY_TO_PERIPH;
DMA_Handle.Init.PeriphInc = DMA_PINC_DISABLE;
@ -231,6 +217,18 @@ mp_obj_t pyb_dac_dma(uint n_args, const mp_obj_t *args, mp_map_t *kw_args) {
__HAL_LINKDMA(&DAC_Handle, DMA_Handle1, DMA_Handle);
DAC_Handle.Instance = DAC;
DAC_Handle.State = HAL_DAC_STATE_RESET;
HAL_DAC_Init(&DAC_Handle);
if (self->state != 3) {
DAC_ChannelConfTypeDef config;
config.DAC_Trigger = DAC_TRIGGER_T6_TRGO;
config.DAC_OutputBuffer = DAC_OUTPUTBUFFER_ENABLE;
HAL_DAC_ConfigChannel(&DAC_Handle, &config, self->dac_channel);
self->state = 3;
}
HAL_DAC_Start_DMA(&DAC_Handle, self->dac_channel, (uint32_t*)bufinfo.buf, bufinfo.len, DAC_ALIGN_8B_R);
/*

1
stmhal/qstrdefsport.h
View File

@ -97,6 +97,7 @@ Q(filtered_xyz)
// for ADC object
Q(ADC)
Q(ADC_all)
Q(read_timed)
Q(read_channel)
Q(read_core_temp)
Q(read_core_vbat)

27
stmhal/timer.c
View File

@ -27,6 +27,7 @@
TIM_HandleTypeDef TIM3_Handle;
TIM_HandleTypeDef TIM5_Handle;
TIM_HandleTypeDef TIM6_Handle;
// TIM3 is set-up for the USB CDC interface
void timer_tim3_init(void) {
@ -57,6 +58,7 @@ void timer_tim3_deinit(void) {
*/
// TIM5 is set-up for the servo controller
// This function inits but does not start the timer
void timer_tim5_init(void) {
// TIM5 clock enable
__TIM5_CLK_ENABLE();
@ -74,6 +76,31 @@ void timer_tim5_init(void) {
HAL_TIM_PWM_Init(&TIM5_Handle);
}
// Init TIM6 with a counter-overflow at the given frequency (given in Hz)
// TIM6 is used by the DAC and ADC for auto sampling at a given frequency
// This function inits but does not start the timer
void timer_tim6_init(uint freq) {
// TIM6 clock enable
__TIM6_CLK_ENABLE();
// Timer runs at SystemCoreClock / 2
// Compute the prescaler value so TIM6 triggers at freq-Hz
uint32_t period = (SystemCoreClock / 2) / freq;
uint32_t prescaler = 1;
while (period > 0xffff) {
period >>= 1;
prescaler <<= 1;
}
// Time base clock configuration
TIM6_Handle.Instance = TIM6;
TIM6_Handle.Init.Period = period - 1;
TIM6_Handle.Init.Prescaler = prescaler - 1;
TIM6_Handle.Init.ClockDivision = 0; // unused for TIM6
TIM6_Handle.Init.CounterMode = TIM_COUNTERMODE_UP; // unused for TIM6
HAL_TIM_Base_Init(&TIM6_Handle);
}
// Interrupt dispatch
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim) {
if (htim == &TIM3_Handle) {

2
stmhal/timer.h
View File

@ -5,6 +5,8 @@
extern TIM_HandleTypeDef TIM3_Handle;
extern TIM_HandleTypeDef TIM5_Handle;
extern TIM_HandleTypeDef TIM6_Handle;
void timer_tim3_init(void);
void timer_tim5_init(void);
void timer_tim6_init(uint freq);