mirror of
https://github.com/kidoman/embd
synced 2024-11-10 19:48:53 +01:00
47 lines
1.0 KiB
Go
47 lines
1.0 KiB
Go
// Package mcp3008 allows interfacing with the mcp3008 8-channel, 10-bit ADC through SPI protocol.
|
|
package mcp3008
|
|
|
|
import (
|
|
"github.com/golang/glog"
|
|
"github.com/kidoman/embd"
|
|
)
|
|
|
|
// MCP3008 represents a mcp3008 8bit DAC.
|
|
type MCP3008 struct {
|
|
Mode byte
|
|
|
|
Bus embd.SPIBus
|
|
}
|
|
|
|
const (
|
|
// SingleMode represents the single-ended mode for the mcp3008.
|
|
SingleMode = 1
|
|
|
|
// DifferenceMode represents the diffenrential mode for the mcp3008.
|
|
DifferenceMode = 0
|
|
)
|
|
|
|
// New creates a representation of the mcp3008 convertor
|
|
func New(mode byte, bus embd.SPIBus) *MCP3008 {
|
|
return &MCP3008{mode, bus}
|
|
}
|
|
|
|
const (
|
|
startBit = 1
|
|
)
|
|
|
|
// AnalogValueAt returns the analog value at the given channel of the convertor.
|
|
func (m *MCP3008) AnalogValueAt(chanNum int) (int, error) {
|
|
var data [3]uint8
|
|
data[0] = startBit
|
|
data[1] = uint8(m.Mode)<<7 | uint8(chanNum)<<4
|
|
data[2] = 0
|
|
|
|
glog.V(2).Infof("mcp3008: sendingdata buffer %v", data)
|
|
if err := m.Bus.TransferAndReceiveData(data[:]); err != nil {
|
|
return 0, err
|
|
}
|
|
|
|
return int(uint16(data[1]&0x03)<<8 | uint16(data[2])), nil
|
|
}
|