hybridgroup.gobot/drivers/spi/mcp3008.go

66 lines
1.6 KiB
Go

package spi
import (
"fmt"
"strconv"
)
// MCP3008DriverMaxChannel is the number of channels of this A/D converter.
const MCP3008DriverMaxChannel = 8
// MCP3008Driver is a driver for the MCP3008 A/D converter.
type MCP3008Driver struct {
*Driver
}
// NewMCP3008Driver creates a new Gobot Driver for MCP3008Driver A/D converter
//
// Params:
// a *Adaptor - the Adaptor to use with this Driver
//
// Optional params:
// spi.WithBusNumber(int): bus to use with this driver
// spi.WithChipNumber(int): chip to use with this driver
// spi.WithMode(int): mode to use with this driver
// spi.WithBitCount(int): number of bits to use with this driver
// spi.WithSpeed(int64): speed in Hz to use with this driver
//
func NewMCP3008Driver(a Connector, options ...func(Config)) *MCP3008Driver {
d := &MCP3008Driver{
Driver: NewDriver(a, "MCP3008"),
}
for _, option := range options {
option(d)
}
return d
}
// Read reads the current analog data for the desired channel.
func (d *MCP3008Driver) Read(channel int) (result int, err error) {
if channel < 0 || channel > MCP3008DriverMaxChannel-1 {
return 0, fmt.Errorf("Invalid channel '%d' for read", channel)
}
tx := make([]byte, 3)
tx[0] = 0x01
tx[1] = byte(8+channel) << 4
tx[2] = 0x00
rx := make([]byte, 3)
err = d.connection.ReadCommandData(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 *MCP3008Driver) AnalogRead(pin string) (value int, err error) {
channel, _ := strconv.Atoi(pin)
value, err = d.Read(channel)
return
}