Table of Contents

• ADC
  • Create ADC driver
  • Use ADC interface
  • API
    • adc.getCurrent()
    • adc.getVoltage()
    • adc.getRawValue()
    • adc.getResolution()

ADC#

The ADC module allows you to create your own device driver with ADC output.Following line of code includes the ADC module: require('adc');.

ADC driver developers may extend this module by adding more functions.

Create ADC driver#

Using Ruff Framework, you just need to write some easy implementation

Below is an example of an ADC driver:

var adc = require('adc');

AdcDriverClass = adc.driver({
    attach: function(options) {
        ...
    },

    exports: {
        getRawValue: function() {
            // raw value from your device
            ...
        },

        getResolution: function() {
            // your resolution is here
            ...
        },
    }
});

As you can see, getRawValue and getResolution are the only two functions you have to implement. getCurrent and getVoltage functions are Ruff built-in functions. Other functions may be provided by ADC driver developers.

Use ADC interface#

Driver developers who use ADC need first to declare the device as ADC type in driver.json.

• type: There are to valid ADC channel types:
  • current: current type,
  • voltage: voltage type
• min: min value for ADC channel
• max: max value for ADC channel
• resistance: resistance value for ADC channel, only works when ADC channel type is current

{
    "inputs": {
        "adc": {
            "type" : "adc",
            "args" : {
                    "type": "current",
                    "min": 0,
                    "max": 5
                }
            }
        }
   }

(driver.json)

You may obtain an ADC instance in your driver code:

var driver = require('ruff-driver');

module.exports = driver({
    attach: function(options) {
        adc = options.getRequired('adc');
    }

    ...
});

API#

adc.getCurrent()#

return the current value specified by your driver.

Example:

try {
    var value = channel.getCurrent();
    console.log(value);
} catch(error) {
    console.log(error);
}

adc.getVoltage()#

return voltage value.

adc.getRawValue()#

return ADC channel raw value.

adc.getResolution()#

return ADC resolution, which is significance bits, e.g. 12 bit.