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| author | Kevin O'Connor <kevin@koconnor.net> | 2020-01-25 10:48:26 -0500 |
|---|---|---|
| committer | Kevin O'Connor <kevin@koconnor.net> | 2020-01-25 10:50:29 -0500 |
| commit | bf3fa979f9a75288aaae74214e5e8536a1fa3b6b (patch) | |
| tree | 336519bc5da42cf0de0606fedb5b552d98e33f1b /src/stm32/adc.c | |
| parent | 264aac585680b36490ed80625e26efde0482af83 (diff) | |
| download | kutter-bf3fa979f9a75288aaae74214e5e8536a1fa3b6b.tar.gz kutter-bf3fa979f9a75288aaae74214e5e8536a1fa3b6b.tar.xz kutter-bf3fa979f9a75288aaae74214e5e8536a1fa3b6b.zip | |
stm32: Increase adc sample time
Increase the sample time register from 3 to 4 (which adds about ~1.5us
to each adc sample).
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Diffstat (limited to 'src/stm32/adc.c')
| -rw-r--r-- | src/stm32/adc.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/src/stm32/adc.c b/src/stm32/adc.c index ac769c4f..efe71a2f 100644 --- a/src/stm32/adc.c +++ b/src/stm32/adc.c @@ -35,9 +35,9 @@ static const uint8_t adc_pins[] = { #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 +// stm32f103: ADC clock=9Mhz, Tconv=12.5, Tsamp=41.5, total=6.000us +// stm32f407: ADC clock=21Mhz, Tconv=12, Tsamp=84, total=4.571us +// stm32f446: ADC clock=22.5Mhz, Tconv=12, Tsamp=84, total=4.267us struct gpio_adc gpio_adc_setup(uint32_t pin) @@ -66,7 +66,7 @@ gpio_adc_setup(uint32_t pin) // Enable the ADC if (!is_enabled_pclock(adc_base)) { enable_pclock(adc_base); - uint32_t aticks = 3; // 2.5-3.2us (depending on stm32 chip) + uint32_t aticks = 4; // 4-6us sample time (depending on stm32 chip) adc->SMPR1 = (aticks | (aticks << 3) | (aticks << 6) | (aticks << 9) | (aticks << 12) | (aticks << 15) | (aticks << 18) | (aticks << 21) |