1 files changed, 207 insertions, 0 deletions
diff --git a/brother-info/main.go b/brother-info/main.go
new file mode 100644
index 0000000..b65b1dc
--- /dev/null
+++ b/brother-info/main.go
@@ -0,0 +1,207 @@
+package main
+
+import (
+	"io"
+	"log"
+	"os"
+	"time"
+)
+
+func decodeBitfieldErrors(b byte, errors [8]string) []string {
+	var result []string
+	for i := uint(0); i < 8; i++ {
+		if b&(1<<i) != 0 {
+			result = append(result, errors[i])
+		}
+	}
+	return result
+}
+
+// -----------------------------------------------------------------------------
+
+type brotherStatus struct {
+	errors []string
+}
+
+// TODO: What exactly do we need? Probably extend as needed.
+func decodeStatusInformation(d []byte) brotherStatus {
+	var status brotherStatus
+	status.errors = append(status.errors, decodeBitfieldErrors(d[8], [8]string{
+		"no media", "end of media", "cutter jam", "?", "printer in use",
+		"printer turned off", "high-voltage adapter", "fan motor error"})...)
+	status.errors = append(status.errors, decodeBitfieldErrors(d[9], [8]string{
+		"replace media", "expansion buffer full", "communication error",
+		"communication buffer full", "cover open", "cancel key",
+		"media cannot be fed", "system error"})...)
+	return status
+}
+
+// -----------------------------------------------------------------------------
+
+func printStatusInformation(d []byte) {
+	if d[0] != 0x80 || d[1] != 0x20 || d[2] != 0x42 || d[3] != 0x34 {
+		log.Println("unexpected status fixed bytes")
+	}
+
+	// Model code.
+	switch b := d[4]; b {
+	case 0x38:
+		log.Println("model: QL-800")
+	case 0x39:
+		log.Println("model: QL-810W")
+	case 0x41:
+		log.Println("model: QL-820NWB")
+	default:
+		log.Println("model:", b)
+	}
+
+	// d[6] seems to be 0x00 in a real-world QL-800.
+	if d[5] != 0x30 || d[6] != 0x30 || d[7] != 0x00 {
+		log.Println("unexpected status fixed bytes")
+	}
+
+	// Error information 1.
+	for _, e := range decodeBitfieldErrors(d[8], [8]string{
+		"no media", "end of media", "cutter jam", "?", "printer in use",
+		"printer turned off", "high-voltage adapter", "fan motor error"}) {
+		log.Println("error:", e)
+	}
+
+	// Error information 2.
+	for _, e := range decodeBitfieldErrors(d[9], [8]string{
+		"replace media", "expansion buffer full", "communication error",
+		"communication buffer full", "cover open", "cancel key",
+		"media cannot be fed", "system error"}) {
+		log.Println("error:", e)
+	}
+
+	// Media width.
+	log.Println("media width:", d[10], "mm")
+
+	// Media type.
+	switch b := d[11]; b {
+	case 0x00:
+		log.Println("media: no media")
+	case 0x4a:
+		log.Println("media: continuous length tape")
+	case 0x4b:
+		log.Println("media: die-cut labels")
+	default:
+		log.Println("media:", b)
+	}
+
+	// d[14] seems to be 0x14 in a real-world QL-800.
+	if d[12] != 0x00 || d[13] != 0x00 || d[14] != 0x3f {
+		log.Println("unexpected status fixed bytes")
+	}
+
+	// Mode.
+	log.Println("mode:", d[15])
+
+	if d[16] != 0x00 {
+		log.Println("unexpected status fixed bytes")
+	}
+
+	// Media length.
+	log.Println("media width:", d[17], "mm")
+
+	// Status type.
+	switch b := d[18]; b {
+	case 0x00:
+		log.Println("status type: reply to status request")
+	case 0x01:
+		log.Println("status type: printing completed")
+	case 0x02:
+		log.Println("status type: error occurred")
+	case 0x04:
+		log.Println("status type: turned off")
+	case 0x05:
+		log.Println("status type: notification")
+	case 0x06:
+		log.Println("status type: phase change")
+	default:
+		log.Println("status type:", b)
+	}
+
+	// Phase type.
+	switch b := d[19]; b {
+	case 0x00:
+		log.Println("phase state: receiving state")
+	case 0x01:
+		log.Println("phase state: printing state")
+	default:
+		log.Println("phase state:", b)
+	}
+
+	// Phase number.
+	log.Println("phase number:", int(d[20])*256+int(d[21]))
+
+	// Notification number.
+	switch b := d[22]; b {
+	case 0x00:
+		log.Println("notification number: not available")
+	case 0x03:
+		log.Println("notification number: cooling (started)")
+	case 0x04:
+		log.Println("notification number: cooling (finished)")
+	default:
+		log.Println("notification number:", b)
+	}
+
+	// d[25] seems to be 0x01 in a real-world QL-800.
+	if d[23] != 0x00 || d[24] != 0x00 || d[25] != 0x00 || d[26] != 0x00 ||
+		d[27] != 0x00 || d[28] != 0x00 || d[29] != 0x00 || d[30] != 0x00 ||
+		d[31] != 0x00 {
+		log.Println("unexpected status fixed bytes")
+	}
+}
+
+func main() {
+	// Linux usblp module, located in /drivers/usb/class/usblp.c
+	// (at least that's where the trails go, I don't understand the code)
+	f, err := os.OpenFile("/dev/usb/lp0", os.O_RDWR, 0)
+	if err != nil {
+		log.Fatalln(err)
+	}
+	defer f.Close()
+
+	// Flush any former responses in the printer's queue.
+	for {
+		dummy := make([]byte, 32)
+		if _, err := f.Read(dummy); err == io.EOF {
+			break
+		}
+	}
+
+	// Clear the print buffer.
+	invalidate := make([]byte, 400)
+	if _, err := f.Write(invalidate); err != nil {
+		log.Fatalln(err)
+	}
+
+	// Initialize.
+	if _, err := f.WriteString("\x1b\x40"); err != nil {
+		log.Fatalln(err)
+	}
+
+	// Request status information.
+	if _, err := f.WriteString("\x1b\x69\x53"); err != nil {
+		log.Fatalln(err)
+	}
+
+	// We need to poll the device.
+	status := make([]byte, 32)
+	for {
+		if n, err := f.Read(status); err == io.EOF {
+			time.Sleep(10 * time.Millisecond)
+		} else if err != nil {
+			log.Fatalln(err)
+		} else if n < 32 {
+			log.Fatalln("invalid read")
+		} else {
+			break
+		}
+	}
+
+	printStatusInformation(status)
+}