2.3 Analog IO
- brief: set analog reference voltage to a particular value according to different type.
- DEFAULT: 5 Volt;
- INTERNAL: 2.56 Volt
- EXTERNAL: get the voltage value via AREF pin. There must be a 5K ohm pull-up resistor.
- param:
- type: DEFAULT, INTERNAL or EXTERNAL.
- return: void.
- brief: read analog voltage from a particular pin, at a period about 100US.
- param:
- pin: analog IO pin index, must be a value between 0 and 5, corresponding to analog pin A0 ~ A5.
- return: int, between 0 and 1023.
- brief: write voltage value to pin, by PWM.
- Arduino PWM is typically of frequency 490HZ.
- On an Arduino UNO, digital pins 3, 5, 6, 9, 10, 11 with a ~ sign support PWM analog output.
- PWM output is of 8 bits, namely, a value between 0 and 255.
- param:
- pin: analog IO pin index, must be a value between 0 and 5, corresponding to analog pin A0 ~ A5.
- value: HIGH or LOW, where HIGH is for high level voltage, LOW is for low level voltage.
- return: void.
Last modified 5yr ago