schnutibox/main.go

72 lines
1.1 KiB
Go

// https://medium.com/coinmonks/iot-tutorial-read-tags-from-a-usb-rfid-reader-with-raspberry-pi-and-node-red-from-scratch-4554836be127
// nolint: gochecknoglobals, lll, forbidigo
package main
import (
"fmt"
"log"
"os"
)
const newLine = 40
var charMap = map[byte]string{
30: "1",
31: "2",
32: "3",
33: "4",
34: "5",
35: "6",
36: "7",
37: "8",
38: "9",
39: "0",
}
func main() {
d, err := os.Open("/dev/hidraw7")
if err != nil {
log.Fatal(err)
}
id := make(chan string)
go func() {
buf := make([]byte, 3)
rfid := ""
for {
// Reading the RFID reader.
_, err := d.Read(buf)
if err != nil {
log.Print(err)
continue
}
// 40 means "\n" and is an indicator that the input is complete.
// Send the id string to the consumer channel.
if buf[2] == newLine {
id <- rfid
rfid = ""
continue
}
// Check if byte is in the charMap and if its true, append it to the rfid string.
// It waits till next read and checks for the newline byte.
c, ok := charMap[buf[2]]
if ok {
rfid += c
}
}
}()
// Wait for an RFID ID and do something with it.
for {
rfid := <-id
fmt.Println(rfid)
}
}