godaq

package module
v0.0.0-...-cb33ac4 Latest Latest
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 Go to latest Published: Oct 15, 2020 License: Apache-2.0 Imports: 13 Imported by: 0

README

Golang bindings for OpenDAQ

OpenDAQ is an open source data acquisition device.

The hardware uses a VCP (Virtual COM Port) USB interface. The communication protocol is described here.

Note: This project is in an early stage. Only a small subset of the commands is supported.

Installation

Install godaq and its dependencies to your src directory:

go get -v github.com/opendaq/godaq

Updating:

go get -u -v github.com/opendaq/godaq

Usage example

package main

import (
	"fmt"
	"log"
	"time"

	"github.com/opendaq/godaq"
)

func checkErr(err error) {
	if err != nil {
		log.Fatal(err)
	}
}

func main() {
	daq, err := godaq.New("/dev/ttyUSB0")
	checkErr(err)
	defer daq.Close()

	model, version, serial, err := daq.GetInfo()
	checkErr(err)
	fmt.Println("model:", model, "version:", version, "serial:", serial)

	checkErr(daq.SetLED(1, godaq.RED))

	// Set the output voltage to 2 V
	checkErr(daq.SetAnalog(1, 2.0))

	// Configure the ADC: read from input 1 with gainID=1,
	// average 10 samples each time
	checkErr(daq.ConfigureADC(1, 0, 1, 10))

	// Read 20 samples
	for i := 0; i < 20; i++ {
		val, err := daq.ReadAnalog()
		checkErr(err)
		fmt.Println(val)
		time.Sleep(100*time.Millisecond)
	}
}

Documentation

Index

Constants

View Source 
const (
	AIN         = 1
	AIN_CFG     = 2
	PIO         = 3
	AIN_ALL     = 4
	PIO_DIR     = 5
	PORT        = 7
	PORT_DIR    = 9
	SET_DAC     = 13
	LED_W       = 18
	SET_ANALOG  = 24
	GET_CALIB   = 36
	ID_CONFIG   = 39
	GET_AIN_CFG = 40
)
View Source 
const ModelMId = 1
View Source 
const ModelNId = 3
View Source 
const ModelSId = 2

Variables

View Source 
var (
	ErrUnknownModel    = errors.New("Unknown device model number")
	ErrInvalidLed      = errors.New("Invalid LED number")
	ErrInvalidInput    = errors.New("Invalid input number")
	ErrInvalidOutput   = errors.New("Invalid output number")
	ErrInvalidPIO      = errors.New("Invalid PIO number")
	ErrInvalidGainID   = errors.New("Invalid gain ID")
	ErrInvalidID       = errors.New("ID out of range")
	ErrInvalidPIOValue = errors.New("Invalid PIO value")
)
View Source 
var (
	ErrChecksum      = errors.New("Checksum error")
	ErrInvalidLength = errors.New("Invalid message length")
	ErrNakReceived   = errors.New("NAK response received")
)

Functions

func ListPorts 

func ListPorts() ([]string, error)

List all available USB-serial ports (Linux only)

Types

type ADC 

type ADC struct {
	Bits       uint
	Signed     bool
	Invert     bool
	VMin, VMax float32
	Gains      []float32
}

Analog-to-digital converter

func (*ADC) ToVolts 

func (adc *ADC) ToVolts(raw int, gainId uint, cal1, cal2 Calib) float32

Convert an ADC value to volts cal1: pre-PGA calibration values cal2: post-PGA calibration values

type Calib 

type Calib struct {
	Gain   float32 // Gain calibration (-1 to 1)
	Offset float32 // Offset calibraton in ADUs
}

type Color 

type Color uint8
const (
	OFF Color = iota
	GREEN
	RED
	YELLOW
)

type CommandNumber 

type CommandNumber uint8

type DAC 

type DAC struct {
	Bits       uint
	Signed     bool
	Invert     bool
	VMin, VMax float32
}

Digital-to-analog converter

func (*DAC) FromVolts 

func (dac *DAC) FromVolts(v float32, cal Calib) int

Convert a voltage to a DAC value

type DevicePort 

type DevicePort struct {
	Model uint8
	Port  string
}

func ListDevicePorts 

func ListDevicePorts() ([]DevicePort, error)

type HwFeatures 

type HwFeatures struct {
	Name                              string
	NPIOs, NLeds                      uint
	NInputs, NOutputs, NHiddenOutputs uint
	NCalibRegs                        uint
	Dac                               DAC
	Adc                               ADC
}

type HwModel 

type HwModel interface {
	GetFeatures() HwFeatures
	GetCalibIndex(isOutput, diffMode, secondStage bool, n, gainId uint) (uint, error)
	CheckValidInputs(pos, neg uint) error
}

type Message 

type Message struct {
	Number CommandNumber
	Body   []byte
}

func (*Message) Marshal 

func (m *Message) Marshal() ([]byte, error)

type ModelM 

type ModelM struct {
	HwFeatures
}

func NewModelM 

func NewModelM() *ModelM

func (*ModelM) CheckValidInputs 

func (m *ModelM) CheckValidInputs(pos, neg uint) error

func (*ModelM) GetCalibIndex 

func (m *ModelM) GetCalibIndex(isOutput, diffMode, secondStage bool, n, gainId uint) (uint, error)

Get the index of a calibration register. Each register contains a pair of calibration values: a gain and and offset.

isOutput: Obtain the calibration values of an output diffMode: Some models have different calibration values depending on the input mode (single-ended or differential) secondStage: The inputs with a PGA need two calibration registers. One is applied before the PGA and the other is applied after the PGA (second stage)

func (*ModelM) GetFeatures 

func (m *ModelM) GetFeatures() HwFeatures

type ModelN 

type ModelN struct {
	HwFeatures
}

func NewModelN 

func NewModelN() *ModelN

func (*ModelN) CheckValidInputs 

func (m *ModelN) CheckValidInputs(pos, neg uint) error

func (*ModelN) GetCalibIndex 

func (m *ModelN) GetCalibIndex(isOutput, diffMode, secondStage bool, n, gainId uint) (uint, error)

func (*ModelN) GetFeatures 

func (m *ModelN) GetFeatures() HwFeatures

type ModelS 

type ModelS struct {
	HwFeatures
}

func NewModelS 

func NewModelS() *ModelS

func (*ModelS) CheckValidInputs 

func (m *ModelS) CheckValidInputs(pos, neg uint) error

func (*ModelS) GetCalibIndex 

func (m *ModelS) GetCalibIndex(isOutput, diffMode, secondStage bool, n, gainId uint) (uint, error)

func (*ModelS) GetFeatures 

func (m *ModelS) GetFeatures() HwFeatures

type OpenDAQ 

type OpenDAQ struct {
	HwFeatures

	sync.Mutex
	// contains filtered or unexported fields
}

func New 

func New(port string) (*OpenDAQ, error)

func (*OpenDAQ) Close 

func (daq *OpenDAQ) Close() error

func (*OpenDAQ) ConfigureADC 

func (daq *OpenDAQ) ConfigureADC(posInput, negInput, gainId uint, nSamples uint8) error

func (*OpenDAQ) GetCalib 

func (daq *OpenDAQ) GetCalib(isOutput, diffMode, secondStage bool, n, gainId uint) Calib

Return the calibration values for a given input or output. The gain ID and the input mode (single-ended or differential) are needed. Different device models use different calibration schemas.

func (*OpenDAQ) GetInfo 

func (daq *OpenDAQ) GetInfo() (model, version uint8, serial string, err error)

func (*OpenDAQ) ReadADC 

func (daq *OpenDAQ) ReadADC() (int16, error)

Read a raw value from the ADC

func (*OpenDAQ) ReadAnalog 

func (daq *OpenDAQ) ReadAnalog() (float32, error)

Read a value in volts from the ADC

func (*OpenDAQ) ReadPIO 

func (daq *OpenDAQ) ReadPIO(n uint) (uint8, error)

func (*OpenDAQ) ReadPort 

func (daq *OpenDAQ) ReadPort() (uint8, error)

ead all PIO values.

func (*OpenDAQ) SetAnalog 

func (daq *OpenDAQ) SetAnalog(n uint, val float32) error

Set the voltage at output n

func (*OpenDAQ) SetDAC 

func (daq *OpenDAQ) SetDAC(n uint, val int) error

Set the raw value of the DAC at output n

func (*OpenDAQ) SetId 

func (daq *OpenDAQ) SetId(id uint32) (uint16, error)

func (*OpenDAQ) SetLED 

func (daq *OpenDAQ) SetLED(n uint, c Color) error

func (*OpenDAQ) SetPIO 

func (daq *OpenDAQ) SetPIO(n uint, value bool) error

func (*OpenDAQ) SetPIODir 

func (daq *OpenDAQ) SetPIODir(n uint, out bool) error

func (*OpenDAQ) SetPort 

func (daq *OpenDAQ) SetPort(value_port uint8) error

Write all PIO values.

func (*OpenDAQ) SetPortDir 

func (daq *OpenDAQ) SetPortDir(dir_port uint8) error

Configure all PIO direction.

Source Files

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Directories

Path Synopsis

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