1 files changed, 89 insertions, 0 deletions
diff --git a/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/io/i2c/example/displayip/main.go b/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/io/i2c/example/displayip/main.go
new file mode 100644
index 0000000..58fe694
--- /dev/null
+++ b/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/io/i2c/example/displayip/main.go
@@ -0,0 +1,89 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package main contains a program that displays the IPv4 address
+// of the machine on an a Grove-LCD RGB backlight.
+package main
+
+import (
+	"fmt"
+	"net"
+
+	"golang.org/x/exp/io/i2c"
+)
+
+const (
+	DISPLAY_RGB_ADDR  = 0x62
+	DISPLAY_TEXT_ADDR = 0x3e
+)
+
+func main() {
+	d, err := i2c.Open(&i2c.Devfs{Dev: "/dev/i2c-1"}, DISPLAY_RGB_ADDR)
+	if err != nil {
+		panic(err)
+	}
+
+	td, err := i2c.Open(&i2c.Devfs{Dev: "/dev/i2c-1"}, DISPLAY_TEXT_ADDR)
+	if err != nil {
+		panic(err)
+	}
+
+	// Set the backlight color to 100,100,100.
+	write(d, []byte{0, 0})
+	write(d, []byte{1, 0})
+	write(d, []byte{0x08, 0xaa})
+	write(d, []byte{4, 100}) // R value
+	write(d, []byte{3, 100}) // G value
+	write(d, []byte{2, 100}) // B value
+
+	ip, err := resolveIP()
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Printf("host machine IP is %v\n", ip)
+
+	write(td, []byte{0x80, 0x02})        // return home
+	write(td, []byte{0x80, 0x01})        // clean the display
+	write(td, []byte{0x80, 0x08 | 0x04}) // no cursor
+	write(td, []byte{0x80, 0x28})        // two lines
+
+	for _, s := range ip {
+		write(td, []byte{0x40, byte(s)})
+	}
+}
+
+func write(d *i2c.Device, buf []byte) {
+	err := d.Write(buf)
+	if err != nil {
+		panic(err)
+	}
+}
+
+func resolveIP() (string, error) {
+	var ip net.IP
+	ifaces, err := net.Interfaces()
+	if err != nil {
+		panic(err)
+	}
+	for _, i := range ifaces {
+		addrs, err := i.Addrs()
+		if err != nil {
+			panic(err)
+		}
+		for _, addr := range addrs {
+			switch v := addr.(type) {
+			case *net.IPNet:
+				ip = v.IP
+			case *net.IPAddr:
+				ip = v.IP
+			}
+			ip = ip.To4()
+			if ip != nil && ip.String() != "127.0.0.1" {
+				return ip.String(), nil
+			}
+		}
+	}
+	return "", fmt.Errorf("cannot resolve the IP")
+}