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Diffstat (limited to 'tests/adc-power/adc-power.c')
| -rw-r--r-- | tests/adc-power/adc-power.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/tests/adc-power/adc-power.c b/tests/adc-power/adc-power.c new file mode 100644 index 0000000..817671c --- /dev/null +++ b/tests/adc-power/adc-power.c @@ -0,0 +1,94 @@ +/** + * 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 */ + 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 + + /* + * 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); +} + +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(0); + unsigned int v2 = read_adc_naiive(1); + unsigned int tconv = TIM_CNT(TIMER); +#endif + + printf("ton: %u, tconv: %u, v1: %u, v2: %u\n", td, tconv, v1, v2); +} + +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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