mcp3008.go

package mcp3008

import (
	// "fmt"
	"periph.io/x/conn/v3/spi"
)

type mcp3008dev struct {
	spiConn     spi.Conn
	channel     int
	value       uint16
}

func NewMCP3008(spiConn spi.Conn, channel int) *mcp3008dev {
	return &mcp3008dev{
		spiConn:     spiConn,
		channel:     channel,
		value:       0,
	}
}

func (dev *mcp3008dev) Read() uint16 {
	if dev.channel <0 || dev.channel>7 {
		return dev.value
	}
	ch := byte(dev.channel)
	w := []byte{0x1 , byte(ch+8) << 4, 0x0}
	r := []byte{0, 0, 0}
	err := dev.spiConn.Tx(w, r)
	if err != nil {
		return dev.value
	}
	
	l:=uint16(r[2])
	h:=uint16(r[1])<<8
	v:= l + h

	// if (ch == 3) {
	// 	fmt.Printf("%b %b %b    %4d %4d %d \n", w[0], w[1], w[2], r[1], r[2], v)
	// }
	
	return v
}