hybridgroup.gobot/drivers/spi/mcp3004.go

103 lines
2.7 KiB
Go

package spi
import (
"errors"
"strconv"
"gobot.io/x/gobot"
)
// MCP3004DriverMaxChannel is the number of channels of this A/D converter.
const MCP3004DriverMaxChannel = 4
// MCP3004Driver is a driver for the MCP3008 A/D converter.
type MCP3004Driver struct {
name string
connector Connector
connection Connection
Config
gobot.Commander
}
// NewMCP3004Driver creates a new Gobot Driver for MCP3004 A/D converter
//
// Params:
// a *Adaptor - the Adaptor to use with this Driver
//
// Optional params:
// spi.WithBus(int): bus to use with this driver
// spi.WithChip(int): chip to use with this driver
// spi.WithMode(int): mode to use with this driver
// spi.WithBits(int): number of bits to use with this driver
// spi.WithSpeed(int64): speed in Hz to use with this driver
//
func NewMCP3004Driver(a Connector, options ...func(Config)) *MCP3004Driver {
d := &MCP3004Driver{
name: gobot.DefaultName("MCP3004"),
connector: a,
Config: NewConfig(),
}
for _, option := range options {
option(d)
}
return d
}
// Name returns the name of the device.
func (d *MCP3004Driver) Name() string { return d.name }
// SetName sets the name of the device.
func (d *MCP3004Driver) SetName(n string) { d.name = n }
// Connection returns the Connection of the device.
func (d *MCP3004Driver) Connection() gobot.Connection { return d.connection.(gobot.Connection) }
// Start initializes the driver.
func (d *MCP3004Driver) Start() (err error) {
bus := d.GetBusOrDefault(d.connector.GetSpiDefaultBus())
chip := d.GetChipOrDefault(d.connector.GetSpiDefaultChip())
mode := d.GetModeOrDefault(d.connector.GetSpiDefaultMode())
bits := d.GetBitsOrDefault(d.connector.GetSpiDefaultBits())
maxSpeed := d.GetSpeedOrDefault(d.connector.GetSpiDefaultMaxSpeed())
d.connection, err = d.connector.GetSpiConnection(bus, chip, mode, bits, maxSpeed)
if err != nil {
return err
}
return nil
}
// Halt stops the driver.
func (d *MCP3004Driver) Halt() (err error) {
return
}
// Read reads the current analog data for the desired channel.
func (d *MCP3004Driver) Read(channel int) (result int, err error) {
if channel < 0 || channel > MCP3004DriverMaxChannel-1 {
return 0, errors.New("Invalid channel for read")
}
tx := make([]byte, 3)
tx[0] = 0x01
tx[1] = byte(8+channel) << 4
tx[2] = 0x00
rx := make([]byte, 3)
err = d.connection.Tx(tx, rx)
if err == nil && len(rx) == 3 {
result = int((rx[1]&0x3))<<8 + int(rx[2])
}
return result, err
}
// AnalogRead returns value from analog reading of specified pin
func (d *MCP3004Driver) AnalogRead(pin string) (value int, err error) {
channel, _ := strconv.Atoi(pin)
value, err = d.Read(channel)
return
}