works kinda

go.mod

@@ -0,0 +1,5 @@
+module gitlab.com/wobcom/iot/schnutibox
+
+go 1.16
+
+require github.com/karalabe/hid v1.0.0

go.sum

@@ -0,0 +1,2 @@
+github.com/karalabe/hid v1.0.0 h1:+/CIMNXhSU/zIJgnIvBD2nKHxS/bnRHhhs9xBryLpPo=
+github.com/karalabe/hid v1.0.0/go.mod h1:Vr51f8rUOLYrfrWDFlV12GGQgM5AT8sVh+2fY4MPeu8=

main.go

@@ -0,0 +1,80 @@
+// 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, godox
+package main
+
+import (
+	"fmt"
+	"log"
+
+	"github.com/karalabe/hid"
+)
+
+const (
+	product = 0x27db
+	vendor  = 0x16c0
+)
+
+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() {
+	readerInfo := hid.Enumerate(vendor, product)[0]
+
+	d, err := readerInfo.Open()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	id := make(chan string)
+
+	go func() {
+		buf := make([]byte, 3)
+
+		rfid := ""
+
+		for {
+			// Reading the RFID reader.
+			// TODO: Check if "/dev/hidraw" can be used.
+			_, 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)
+	}
+}