hybridgroup.gobot/drivers/spi/mcp3304.go

73 lines
1.8 KiB
Go

package spi
import (
"fmt"
"strconv"
"gobot.io/x/gobot/v2"
)
// MCP3304DriverMaxChannel is the number of channels of this A/D converter.
const MCP3304DriverMaxChannel = 8
// MCP3304Driver is a driver for the MCP3304 A/D converter.
type MCP3304Driver struct {
*Driver
}
// NewMCP3304Driver creates a new Gobot Driver for MCP3304Driver 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 NewMCP3304Driver(a Connector, options ...func(Config)) *MCP3304Driver {
d := &MCP3304Driver{
Driver: NewDriver(a, "MCP3304"),
}
for _, option := range options {
option(d)
}
return d
}
// Read reads the current analog data for the desired channel.
func (d *MCP3304Driver) Read(channel int) (int, error) {
if channel < 0 || channel > MCP3304DriverMaxChannel-1 {
return 0, fmt.Errorf("Invalid channel '%d' for read", channel)
}
tx := make([]byte, 3)
tx[0] = 0x0c + (byte(channel) >> 1)
tx[1] = (byte(channel) & 0x01) << 7
tx[2] = 0x00
rx := make([]byte, 3)
if err := d.connection.ReadCommandData(tx, rx); err != nil || len(rx) != 3 {
return 0, err
}
result := int((rx[1]&0xf))<<8 + int(rx[2])
return result, nil
}
// AnalogRead returns value from analog reading of specified pin, scaled to 0-1023 value.
func (d *MCP3304Driver) AnalogRead(pin string) (int, error) {
channel, _ := strconv.Atoi(pin)
value, err := d.Read(channel)
if err != nil {
return 0, err
}
return int(gobot.ToScale(gobot.FromScale(float64(value), 0, 4095), 0, 1023)), err
}