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| -rw-r--r-- | docs/library/pyb.ADC.rst | 45 |
1 files changed, 4 insertions, 41 deletions
diff --git a/docs/library/pyb.ADC.rst b/docs/library/pyb.ADC.rst index 1256c6a3c..679ba2f5a 100644 --- a/docs/library/pyb.ADC.rst +++ b/docs/library/pyb.ADC.rst @@ -170,44 +170,7 @@ The ADCAll Object The default value is 0xffffffff which means all analog inputs are active. If just the internal channels (16..18) are required, the mask value should be 0x70000. - It is possible to access channle 16..18 values without incurring the side effects of ``ADCAll``:: - - def adcread(chan): # 16 temp 17 vbat 18 vref - assert chan >= 16 and chan <= 18, 'Invalid ADC channel' - start = pyb.millis() - timeout = 100 - stm.mem32[stm.RCC + stm.RCC_APB2ENR] |= 0x100 # enable ADC1 clock.0x4100 - stm.mem32[stm.ADC1 + stm.ADC_CR2] = 1 # Turn on ADC - stm.mem32[stm.ADC1 + stm.ADC_CR1] = 0 # 12 bit - if chan == 17: - stm.mem32[stm.ADC1 + stm.ADC_SMPR1] = 0x200000 # 15 cycles - stm.mem32[stm.ADC + 4] = 1 << 23 - elif chan == 18: - stm.mem32[stm.ADC1 + stm.ADC_SMPR1] = 0x1000000 - stm.mem32[stm.ADC + 4] = 0xc00000 - else: - stm.mem32[stm.ADC1 + stm.ADC_SMPR1] = 0x40000 - stm.mem32[stm.ADC + 4] = 1 << 23 - stm.mem32[stm.ADC1 + stm.ADC_SQR3] = chan - stm.mem32[stm.ADC1 + stm.ADC_CR2] = 1 | (1 << 30) | (1 << 10) # start conversion - while not stm.mem32[stm.ADC1 + stm.ADC_SR] & 2: # wait for EOC - if pyb.elapsed_millis(start) > timeout: - raise OSError('ADC timout') - data = stm.mem32[stm.ADC1 + stm.ADC_DR] # clear down EOC - stm.mem32[stm.ADC1 + stm.ADC_CR2] = 0 # Turn off ADC - return data - - def v33(): - return 4096 * 1.21 / adcread(17) - - def vbat(): - return 1.21 * 2 * adcread(18) / adcread(17) # 2:1 divider on Vbat channel - - def vref(): - return 3.3 * adcread(17) / 4096 - - def temperature(): - return 25 + 400 * (3.3 * adcread(16) / 4096 - 0.76) - - Note that this example is only valid for the F405 MCU and all values are not corrected by Vref and - factory calibration data. + Example:: + + adcall = pyb.ADCAll(12, 0x70000) # 12 bit resolution, internal channels + temp = adcall.read_core_temp() |