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| author | Kevin O'Connor <kevin@koconnor.net> | 2019-11-26 23:06:56 -0500 |
|---|---|---|
| committer | Kevin O'Connor <kevin@koconnor.net> | 2019-11-27 11:16:41 -0500 |
| commit | fc476f22b66c81cb57c161ae843cc434bdeabe26 (patch) | |
| tree | 55fcdce6030a38688438841e854fbc06a13da9a3 /src/stm32/adc.c | |
| parent | 8d93d1a8ef89a3c727fa2f8059961363c785dd78 (diff) | |
| download | kutter-fc476f22b66c81cb57c161ae843cc434bdeabe26.tar.gz kutter-fc476f22b66c81cb57c161ae843cc434bdeabe26.tar.xz kutter-fc476f22b66c81cb57c161ae843cc434bdeabe26.zip | |
stm32: Fix typo in adc startup delay
Fix (harmless) typo and add comments on adc timing.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Diffstat (limited to 'src/stm32/adc.c')
| -rw-r--r-- | src/stm32/adc.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/src/stm32/adc.c b/src/stm32/adc.c index b6aa14b8..3998915f 100644 --- a/src/stm32/adc.c +++ b/src/stm32/adc.c @@ -34,6 +34,11 @@ static const uint8_t adc_pins[] = { #define CR2_FLAGS ADC_CR2_ADON #endif +// ADC timing: +// stm32f103: ADC clock=9Mhz, Tconv=12.5, Tsamp=28.5, total=4.556us +// stm32f407: ADC clock=21Mhz, Tconv=12, Tsamp=56, total=3.238us +// stm32f446: ADC clock=22.5Mhz, Tconv=12, Tsamp=56, total=3.022us + struct gpio_adc gpio_adc_setup(uint32_t pin) { @@ -72,7 +77,7 @@ gpio_adc_setup(uint32_t pin) #if CONFIG_MACH_STM32F1 // Perform calibration - udelay(timer_from_us(1)); + udelay(10); adc->CR2 = ADC_CR2_CAL | CR2_FLAGS; while (adc->CR2 & ADC_CR2_CAL) ; |