Analog I/O support
Analog input is available on D0 through D3. Configure these pins to 2 (ADC) to enable analog sampling.
|
Function |
Micro Pin |
SMT Pin |
TH Pin |
AT Command |
|---|---|---|---|---|
|
ADC0 |
31 |
33 |
20 |
|
|
ADC1 |
30 |
32 |
19 |
|
|
ADC2 |
29 |
31 |
18 |
|
|
ADC3 |
28 |
30 |
17 |
|
|
PWM0 |
7 |
7 |
6 |
|
|
PWM1 |
8 |
8 |
7 |
AV (Analog Voltage Reference) specifies the analog reference voltage used for the 10-bit ADCs. Analog sample data is represented as a 2-byte value. For a 10-bit ADC, the acceptable range is from 0x0000 to 0x03FF. To convert this value to a useful voltage level, apply the following formula:
ADC / 1023 (vREF) = Voltage
Note ADCs sampled through MicroPython will have 12-bit resolution.
Example
An ADC value received is 0x01AE; to convert this into a voltage the hexadecimal value is first converted to decimal (0x01AE = 430). Using the default AV reference of 1.25 V, apply the formula as follows:
430 / 1023 (1.25 V) = 525 mV
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