GY-63_MS5611/libraries/DMM/README.md
rob tillaart 349b871476 0.1.1 DMM
2022-12-21 21:16:14 +01:00

2.7 KiB

Arduino CI Arduino-lint JSON check License: MIT GitHub release

DMM = Digital MultiMeter.

Arduino library for a DMM class.

Description

DMM is a class that uses the Arduino analogRead to make measurements. It is based upon the UNO but will work on some other boards too.

The first version only works as a voltmeter, DC only. It is meant to be extended in the future to be a complete Digital MultiMeter class. that includes amps ohms, diode testing etc.

(this is an old 'toy' project, wrapped into a class)

Interface

  • DMM() constructor.

Configuration

  • begin(uint8_t analogPin, float volts = 5.0, uint16_t maxADC = 1023) configuration.
  • void setMaxVoltage(float maxVoltage)
  • float getMaxVoltage()
  • void setGain(float factor = 1.0) GAIN e.g. due to voltage divider. a 25V to 5V divider has a factor = 5.
  • float getGain() returns the set gain.

Read

  • float readVolts(uint8_t times = 1) read voltage. Times can be set to average multiple measurements.
  • float readMilliVolts(uint8_t times = 1) convenience wrapper.

Calibration

  • float readNoise(uint8_t times = 1) get noise level for accuracy.

Operation

Basic operation is to connect the Arduino GND to the projects GND (or -) and use the configured analog pin to measure (positive) voltage.

By adding a voltage divider one can measure larger voltages. The divider factor can be set with setGain(factor).

To elaborate.

  • GND, VCC

Future

Functional

  • AMPS (how -> measure voltage over a known resistor)
  • OHM (how -> known divider)
  • DIODE (how -> 5V or 0V)
  • CAPS (how -> RC timing)

Must

  • update documentation
  • update examples
  • add use of AREF
    • external or internal 1.1 Volt

Should

  • investigate noise
  • analogReference(EXTERNAL) for external voltage for build in ADC
  • support external ADC e.g. ADS1115 for 16 bit resolution.

Could

  • multichannel compare
  • schema for
  • scope functionality?

Won't