ads1x15

Documentation

Overview

Package ads1x15 controls ADS1015/ADS1115 Analog-Digital Converters (ADC) via I²C interface.

Datasheet

ADS1015: http://www.ti.com/product/ADS1015

ADS1115: http://www.ti.com/product/ADS1115

Example

package main

import (
	"fmt"
	"log"

	"periph.io/x/periph/conn/i2c/i2creg"
	"periph.io/x/periph/conn/physic"
	"periph.io/x/periph/experimental/devices/ads1x15"
	"periph.io/x/periph/host"
)

func main() {
	// Make sure periph is initialized.
	if _, err := host.Init(); err != nil {
		log.Fatal(err)
	}

	// Open default I²C bus.
	bus, err := i2creg.Open("")
	if err != nil {
		log.Fatalf("failed to open I²C: %v", err)
	}
	defer bus.Close()

	// Create a new ADS1115 ADC.
	adc, err := ads1x15.NewADS1115(bus, &ads1x15.DefaultOpts)
	if err != nil {
		log.Fatalln(err)
	}

	// Obtain an analog pin from the ADC.
	pin, err := adc.PinForChannel(ads1x15.Channel0Minus3, 5*physic.Volt, 1*physic.Hertz, ads1x15.SaveEnergy)
	if err != nil {
		log.Fatalln(err)
	}
	defer pin.Halt()

	// Read values from ADC.
	fmt.Println("Single reading")
	reading, err := pin.Read()

	if err != nil {
		log.Fatalln(err)
	}

	fmt.Println(reading)

	// Read values continously from ADC.
	fmt.Println("Continuous reading")
	c := pin.ReadContinuous()

	for reading := range c {
		fmt.Println(reading)
	}
}

Index

• Constants
• Variables
• type Channel
  • func (c Channel) String() string
• type ConversionQuality
• type Dev
  • func NewADS1015(i i2c.Bus, opts *Opts) (*Dev, error)
  • func NewADS1115(i i2c.Bus, opts *Opts) (*Dev, error)
  • func (d *Dev) Halt() error
  • func (d *Dev) PinForChannel(c Channel, maxVoltage physic.ElectricPotential, f physic.Frequency, ...) (PinADC, error)
  • func (d *Dev) String() string
• type Opts
• type PinADC

Examples

• Package

Constants

const I2CAddr uint16 = 0x48

I2CAddr is the default I2C address for the ADS1x15 components.

Variables

var DefaultOpts = Opts{
	I2cAddress: I2CAddr,
}

DefaultOpts are the recommended default options.

Types

type Channel

type Channel int

Channel is the analog reading to do. It can be either an absolute reading or a differential reading between two pins.

const (
	// Absolute reading.
	Channel0 Channel = 4
	Channel1 Channel = 5
	Channel2 Channel = 6
	Channel3 Channel = 7

	// Differential reading.
	Channel0Minus1 Channel = 0
	Channel0Minus3 Channel = 1
	Channel1Minus3 Channel = 2
	Channel2Minus3 Channel = 3
)

func (Channel) String

func (c Channel) String() string

type ConversionQuality

type ConversionQuality int

ConversionQuality represents a request for a compromise between energy saving versus conversion quality.

const (
	// SaveEnergy optimizes the power consumption of the ADC, at the expense of
	// the quality by converting at the highest possible rate.
	SaveEnergy ConversionQuality = 0
	// BestQuality will use the lowest suitable data rate to reduce the impact of
	// the noise on the reading.
	BestQuality ConversionQuality = 1
)

type Dev

type Dev struct {
	// contains filtered or unexported fields
}

Dev is an handle to an ADS1015/ADS1115 ADC.

func NewADS1015

func NewADS1015(i i2c.Bus, opts *Opts) (*Dev, error)

NewADS1015 creates a new driver for the ADS1015 (12-bit ADC).

func NewADS1115

func NewADS1115(i i2c.Bus, opts *Opts) (*Dev, error)

NewADS1115 creates a new driver for the ADS1115 (16-bit ADC).

func (*Dev) Halt

func (d *Dev) Halt() error

Halt implements conn.Resource.

func (*Dev) PinForChannel

func (d *Dev) PinForChannel(c Channel, maxVoltage physic.ElectricPotential, f physic.Frequency, q ConversionQuality) (PinADC, error)

PinForChannel returns an AnalogPin for the requested channel at the requested frequency.

The channel can either be an absolute reading or a differential one.

func (*Dev) String

func (d *Dev) String() string

String implements conn.Resource.

type Opts

type Opts struct {
	I2cAddress uint16
}

Opts holds the configuration options.

type PinADC

type PinADC interface {
	analog.PinADC
	// ReadContinuous opens a channel and reads continuously at the frequency the
	// pin was configured for.
	ReadContinuous() <-chan analog.Sample
}

PinADC represents a pin which is able to read an electric potential.