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