mirror of https://github.com/kidoman/embd
53 lines
1.1 KiB
Go
53 lines
1.1 KiB
Go
package mcp3008
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import (
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"github.com/golang/glog"
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"github.com/kidoman/embd"
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_ "github.com/kidoman/embd/host/all"
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)
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type mcp3008 struct {
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mode int
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bus embd.SPIBus
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}
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const (
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SingleMode = int(1)
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DifferenceMode = int(0)
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)
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func New(mode, spiChan, speed int) (*mcp3008, error) {
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if err := embd.InitSPI(); err != nil {
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return nil, err
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}
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glog.V(3).Infof("mcp3008: getting spiBus with mode: %v, channel: %v, speed: %v", mode, spiChan, speed)
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spiBus := embd.NewSPIBus(embd.SpiMode0, byte(spiChan), speed, 0, 0)
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return &mcp3008{mode, spiBus}, nil
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}
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func (m *mcp3008) AnalogValueAt(chanNum int) (int, error) {
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data := make([]uint8, 3)
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data[0] = 1
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data[1] = uint8(m.mode)<<7 | uint8(chanNum)<<4
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data[2] = 0
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if err := m.bus.TransferAndRecieveData(data); err != nil {
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return 0, err
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}
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return int(uint16(data[1]&0x03)<<8 | uint16(data[2])), nil
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}
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func (m *mcp3008) Close() error {
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glog.V(2).Infoln("mcp3008: performing cleanup")
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if err := m.bus.Close(); err != nil {
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return err
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}
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if err := embd.CloseSPI(); err != nil {
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return err
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}
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return nil
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}
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