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/**
* Testing ADC power up and power down, for timing and actual on/off
* Uses TIM6, because DWT_CYCCNT not available on cm0(+) :(
* (And with no DWT, no ITM timestamping either, get a real mcu!)
*/
#include <stdio.h>
#include <stdint.h>
#include <libopencm3/stm32/adc.h>
#include <libopencm3/stm32/rcc.h>
#include <libopencm3/stm32/timer.h>
#include "adc-power.h"
/* Everyone has tim6 right? */
#define TIMER TIM6
#define TIMER_RCC RCC_TIM6
// TODO - stick this in libopencm3?
#define ARRAY_SIZE(a) (sizeof((a)) / sizeof((a)[0]))
void adc_power_init(void)
{
/* Some basic ADC config, that we won't touch again */
#if defined(STM32F3)
/* silly f303 */
rcc_periph_clock_enable(RCC_ADC12);
rcc_adc_prescale(RCC_CFGR2_ADCxPRES_PLL_CLK_DIV_1, RCC_CFGR2_ADCxPRES_PLL_CLK_DIV_1);
adc_enable_regulator(ADC1);
adc_set_sample_time_on_all_channels(ADC1, ADC_SMPR1_SMP_19DOT5CYC);
adc_set_sample_time(ADC1, ADC_CHANNEL_TEMP, ADC_SMPR1_SMP_181DOT5CYC);
#else
rcc_periph_clock_enable(RCC_ADC1);
adc_set_sample_time_on_all_channels(ADC1, ADC_SMPR_SMP_28CYC);
#if 0
// DANGER DANGER! doing this without DMA is dum.
// but... we're busy polling, we should be right... right?
// (dma across platforms is teh suck)
adc_enable_scan_mode(ADC1);
ADC_CR2 |= ADC_CR2_EOCS; // FIXME
#else
adc_disable_scan_mode(ADC1);
#endif
#endif
adc_enable_temperature_sensor();
adc_enable_vrefint();
/*
* We're going to setup a timer to run at top speed, so... "fast"
* but we don't actually care about the rate itself. We just
* want to collect how many ticks it takes to enable and disable
* the adc.
*/
rcc_periph_clock_enable(TIMER_RCC);
timer_reset(TIMER);
timer_set_prescaler(TIMER, 0);
timer_enable_counter(TIMER);
}
static uint16_t read_adc_naiive(uint8_t channel)
{
uint8_t channel_array[16];
channel_array[0] = channel;
adc_set_regular_sequence(ADC1, 1, channel_array);
adc_start_conversion_regular(ADC1);
while (!adc_eoc(ADC1));
return adc_read_regular(ADC1);
}
static uint16_t compensate_vref(uint16_t adc_count, uint16_t vref_count) {
uint32_t ret = adc_count * ST_VREFINT_CAL;
return (ret / vref_count);
}
static int work_temp(unsigned int ts_v, unsigned int vref) {
// This is important! as the calibration values are give us a slope in mv/C
int raw_temp_mv = compensate_vref(ts_v, vref);
// millivolts gives millcentigrade
float slope = raw_temp_mv - (ST_TSENSE_CAL1_30C * 1.0) / (ST_TSENSE_CAL2_110 * 1.0) - ST_TSENSE_CAL1_30C;
int temp_mc = (110 - 30) * slope + 30.0;
return temp_mc / 10;
}
static float adc_calculate_temp(unsigned int ts_v) {
#if 0
float factor = (110-30) / ((ST_TSENSE_CAL1_30C * 1.0) - (ST_TSENSE_CAL2_110 * 1.0));
return (factor * (ts_v - ST_TSENSE_CAL2_110)) + 30.0;
#else
float factor = (110-30) / ((ST_TSENSE_CAL2_110 * 1.0) - (ST_TSENSE_CAL1_30C * 1.0));
return (factor * (ts_v - ST_TSENSE_CAL1_30C)) + 30.0;
#endif
}
void adc_power_task_up(void) {
TIM_CNT(TIMER) = 0;
adc_power_on(ADC1);
unsigned int td = TIM_CNT(TIMER);
/* just for kicks, let's time some sequences too....
* I mean, we're going to do some conversions right? */
adc_set_single_conversion_mode(ADC1);
#if 0
uint8_t channels[2] = { 0, 1 };
adc_set_regular_sequence(ADC1, ARRAY_SIZE(channels), channels);
TIM_CNT(TIMER) = 0;
adc_start_conversion_regular(ADC1);
while (!adc_eoc(ADC1));
unsigned int v1 = adc_read_regular(ADC1);
while (!adc_eoc(ADC1));
unsigned int v2 = adc_read_regular(ADC1);
unsigned int tconv = TIM_CNT(TIMER);
#else
TIM_CNT(TIMER) = 0;
unsigned int v1 = read_adc_naiive(1);
unsigned int v5 = read_adc_naiive(5);
unsigned int temp_adc = read_adc_naiive(ADC_CHANNEL_TEMP);
unsigned int vref_adc = read_adc_naiive(ADC_CHANNEL_VREF);
// TODO - use vref to adjust temp_adc for non-3v readings!
float temp = adc_calculate_temp(temp_adc);
int tempi = 100 * temp;
unsigned int tconv = TIM_CNT(TIMER);
#endif
printf("ton: %u, tconv: %u, ch1: %u, ch5: %u\n", td, tconv, v1, v5);
printf("\tTemperature: %f (raw count: %u)\n", temp, temp_adc);
}
void adc_power_task_down()
{
TIM_CNT(TIMER) = 0;
adc_power_off(ADC1);
unsigned int td = TIM_CNT(TIMER);
printf("toff in: %u\n", td);
}
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