GY-63_MS5611/libraries/rain

RAIN

Arduino library for rain sensor (analog).

Description

The RAIN sensor is a relative simple device. It measures the resistance of a number of wires when these are put un a liquid (water) The device converts that resistance to a voltage 0..VCC - typical 5V. The more the wires are covered by the liquid, the higher the voltage.

Furthermore the breakout I used to test had a digital output, which becomes HIGH if a certain threshold (to be set with a potentiometer) was reached. The meaning / potential of this digi-out for the library is not clear yet.

The library is EXPERIMENTAL as it needs more testing. (changes of the interface are possible).

Interface

• RAIN(uint8_t port) constructor. port is the internal analog port to use.
• bool begin(float maxVoltage, uint16_t maxSteps) sets the ADC parameters. Allows to be changed runtime, e.g. if voltage fluctuates the math can be adapted by calling begin() again. Might be a separate setVoltage() is more efficient.
• float raw(uint8_t times = 1) makes 1 or more measurements and averages them. returned value is the average number of ADC steps.
• float read(uint8_t times = 1) makes 1 or more measurements, averages them and convert the average to a voltage. THis voltage is returned, and also cached for percentage() and getLevel().

Analysis

• float percentage() returns the last read() to a percentage. Note one needs to call read() again to get a new value as this uses a cached value.
• bool setLevel(uint8_t nr, float voltage) allows a user to set 5 voltage levels.
• uint8_t getLevel() Returns the level of the current cached voltage. See example.

MultiMap

One might use the MultiMap library to map the voltage read to some other, more useful unit. See https://github.com/RobTillaart/MultiMap

Operation

The examples show the basic working of the functions.

Future

Must

• update documentation
  • a lot,
  • links etc.
• test more
  • different salinity
  • different liquids? which?
  • how linear is the device?

Should

• investigate "a scale of wetness"
• add unit-tests
• add examples.
  • interrupt example for digital output capture.
  • multimap example
• investigate possibilities of the digital output
  • how to include
  • example (see above)
• float readExt(float voltage) for external ADC

Could

Won't