From 0029ed768ea0b3626ba8b26c369c409962ff38b6 Mon Sep 17 00:00:00 2001
From: jaseg <git@jaseg.net>
Date: Mon, 24 Dec 2018 18:08:01 +0900
Subject: Make center ADC work in "scope mode"
---
fw/adc.c | 52 +++++-----------------------------------------------
fw/main.c | 4 ++--
2 files changed, 7 insertions(+), 49 deletions(-)
diff --git a/fw/adc.c b/fw/adc.c
index 726e9a8..9deeb72 100644
--- a/fw/adc.c
+++ b/fw/adc.c
@@ -26,7 +26,7 @@ enum adc_channels {
TEMP_CH,
NCH
};
-static volatile uint16_t adc_buf[NCH];
+static volatile uint16_t adc_buf[1024];
void adc_init(void) {
/* The ADC is used for temperature measurement. To compute the temperature from an ADC reading of the internal
@@ -35,15 +35,13 @@ void adc_init(void) {
* The ADC is triggered by compare channel 4 of timer 1. The trigger is set to falling edge to trigger on compare
* match, not overflow.
*/
- ADC1->CFGR1 = ADC_CFGR1_DMAEN | ADC_CFGR1_DMACFG | (2<<ADC_CFGR1_EXTEN_Pos) | (1<<ADC_CFGR1_EXTSEL_Pos);
+ ADC1->CFGR1 = ADC_CFGR1_DMAEN | ADC_CFGR1_DMACFG | (2<<ADC_CFGR1_EXTEN_Pos) | (1<<ADC_CFGR1_EXTSEL_Pos) | ADC_CFGR1_CONT;
/* Clock from PCLK/4 instead of the internal exclusive high-speed RC oscillator. */
ADC1->CFGR2 = (2<<ADC_CFGR2_CKMODE_Pos); /* Use PCLK/4=12MHz */
/* Sampling time 13.5 ADC clock cycles -> total conversion time 2.17us*/
ADC1->SMPR = (2<<ADC_SMPR_SMP_Pos);
- /* Internal VCC and temperature sensor channels */
- ADC1->CHSELR = ADC_CHSELR_CHSEL0 | ADC_CHSELR_CHSEL1 | ADC_CHSELR_CHSEL16 | ADC_CHSELR_CHSEL17;
- /* Enable internal voltage reference and temperature sensor */
- ADC->CCR = ADC_CCR_TSEN | ADC_CCR_VREFEN;
+
+ ADC1->CHSELR = ADC_CHSELR_CHSEL0 | ADC_CHSELR_CHSEL1;
/* Perform ADC calibration */
ADC1->CR |= ADC_CR_ADCAL;
while (ADC1->CR & ADC_CR_ADCAL)
@@ -55,7 +53,7 @@ void adc_init(void) {
/* Configure DMA 1 Channel 1 to get rid of all the data */
DMA1_Channel1->CPAR = (unsigned int)&ADC1->DR;
DMA1_Channel1->CMAR = (unsigned int)&adc_buf;
- DMA1_Channel1->CNDTR = NCH;
+ DMA1_Channel1->CNDTR = sizeof(adc_buf)/sizeof(adc_buf[0]);
DMA1_Channel1->CCR = (0<<DMA_CCR_PL_Pos);
DMA1_Channel1->CCR |=
DMA_CCR_CIRC /* circular mode so we can leave it running indefinitely */
@@ -70,49 +68,9 @@ void adc_init(void) {
NVIC_SetPriority(DMA1_Channel1_IRQn, 3<<5);
}
-uint16_t buf_a[256];
-uint16_t buf_b[256];
-int bufp = 0;
-
void DMA1_Channel1_IRQHandler(void) {
- /* This interrupt takes either 1.2us or 13us. It can be pre-empted by the more timing-critical UART and LED timer
- * interrupts. */
- static int count = 0; /* oversampling accumulator sample count */
- static uint32_t adc_aggregate[NCH] = {0}; /* oversampling accumulator */
-
/* Clear the interrupt flag */
DMA1->IFCR |= DMA_IFCR_CGIF1;
- for (int i=0; i<NCH; i++)
- adc_aggregate[i] += adc_buf[i];
-
- if (++count == (1<<ADC_OVERSAMPLING)) {
- for (int i=0; i<NCH; i++)
- adc_aggregate[i] >>= ADC_OVERSAMPLING;
- /* This has been copied from the code examples to section 12.9 ADC>"Temperature sensor and internal reference
- * voltage" in the reference manual with the extension that we actually measure the supply voltage instead of
- * hardcoding it. This is not strictly necessary since we're running off a bored little LDO but it's free and
- * the current supply voltage is a nice health value.
- */
- adc_data.adc_vcc_mv = (3300 * VREFINT_CAL)/(adc_aggregate[VREF_CH]);
-
- int64_t read = adc_aggregate[TEMP_CH] * 10 * 10000;
- int64_t vcc = adc_data.adc_vcc_mv;
- int64_t cal = TS_CAL1 * 10 * 10000;
- adc_data.adc_temp_celsius_tenths = 300 + ((read/4096 * vcc) - (cal/4096 * 3300))/43000;
-
- adc_data.adc_vmeas_a_mv = (adc_aggregate[VMEAS_A]*13300L)/4096 * vcc / 3300;
- adc_data.adc_vmeas_b_mv = (adc_aggregate[VMEAS_B]*13300L)/4096 * vcc / 3300;
-
- buf_a[bufp] = adc_data.adc_vmeas_a_mv;
- buf_b[bufp] = adc_data.adc_vmeas_b_mv;
- if (++bufp >= sizeof(buf_a)/sizeof(buf_a[0])) {
- bufp = 0;
- }
-
- count = 0;
- for (int i=0; i<NCH; i++)
- adc_aggregate[i] = 0;
- }
}
diff --git a/fw/main.c b/fw/main.c
index b766488..07d065d 100644
--- a/fw/main.c
+++ b/fw/main.c
@@ -69,8 +69,8 @@ int main(void) {
TIM1->CCR4 = 1;
TIM1->DIER = TIM_DIER_UIE;
- TIM1->PSC = SystemCoreClock/1000000 - 1; /* 1.0us/tick */
- TIM1->ARR = 20-1; /* 20us */
+ TIM1->PSC = SystemCoreClock/500000 - 1; /* 0.5us/tick */
+ TIM1->ARR = 25-1;
/* Preload all values */
TIM1->EGR |= TIM_EGR_UG;
TIM1->CR1 = TIM_CR1_ARPE;
--
cgit