Working Android version.

go.mod

@@ -3,7 +3,7 @@ module git.wow.st/gmp/hrm
 go 1.13
 
 require (
-	gioui.org v0.0.0-20191101175813-af353822fa5e
+	gioui.org v0.0.0-20191126175243-2ca2e5462f16
-	git.wow.st/gmp/ble v0.0.0-20191101185903-829baedeac2b
+	git.wow.st/gmp/ble v0.0.0-20191127154437-321b94a48682
-	gopkg.in/yaml.v2 v2.2.4
+	gopkg.in/yaml.v2 v2.2.7
 )

go.sum

@@ -1,14 +1,8 @@
 dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7gZCb22OMCxBHrMx7a5I7Hp++hsVxbQ4BYO7hU=
-gioui.org v0.0.0-20191031200634-4e71f195ab51 h1:Epxo/e6oPvbDMMB8rrpmUlBe6ELeDpRuLzFUGfT6kJM=
+gioui.org v0.0.0-20191126175243-2ca2e5462f16 h1:p31rtmKm51xpj2QtqGNlljAyHEP1oStU8MDRl2Dv7Gs=
-gioui.org v0.0.0-20191031200634-4e71f195ab51/go.mod h1:KqFFi2Dq5gYA3FJ0sDOt8OBXoMsuxMtE8v2f0JExXAY=
+gioui.org v0.0.0-20191126175243-2ca2e5462f16/go.mod h1:KqFFi2Dq5gYA3FJ0sDOt8OBXoMsuxMtE8v2f0JExXAY=
-gioui.org v0.0.0-20191101175813-af353822fa5e h1:8NpYJwhzVg0A34MikFWRS65/PoYcluBGWZ3fgy8iXIg=
+git.wow.st/gmp/ble v0.0.0-20191127154437-321b94a48682 h1:8b9kt3AbWqpJwLukguXBGyUbidbgxpxrToUSX5rUSDE=
-gioui.org v0.0.0-20191101175813-af353822fa5e/go.mod h1:KqFFi2Dq5gYA3FJ0sDOt8OBXoMsuxMtE8v2f0JExXAY=
+git.wow.st/gmp/ble v0.0.0-20191127154437-321b94a48682/go.mod h1:Fh9BYe6AckJS7dzv2LFPr/wSYVMROUwmtc01VyQmuZo=
-git.wow.st/gmp/ble v0.0.0-20191030160916-4e4c07169707 h1:46SbpM1pnBe+VNUSohkKz16s/8BFY2+hzRLZEiRR1Y0=
-git.wow.st/gmp/ble v0.0.0-20191030160916-4e4c07169707/go.mod h1:MiidWVofL6FTtRokC5JGBdVUhKyvZtnia5noj08r944=
-git.wow.st/gmp/ble v0.0.0-20191101184817-0ab45a1d9d54 h1:Tdomh1qilIgDXWU+CksM6682BKomGKFyw3+JXcP0LLo=
-git.wow.st/gmp/ble v0.0.0-20191101184817-0ab45a1d9d54/go.mod h1:MiidWVofL6FTtRokC5JGBdVUhKyvZtnia5noj08r944=
-git.wow.st/gmp/ble v0.0.0-20191101185903-829baedeac2b h1:ccSukYa0YCYZEXaweXXf/103edYKBECsQjExQBTH0vE=
-git.wow.st/gmp/ble v0.0.0-20191101185903-829baedeac2b/go.mod h1:MiidWVofL6FTtRokC5JGBdVUhKyvZtnia5noj08r944=
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
 github.com/go-gl/glfw v0.0.0-20190409004039-e6da0acd62b1/go.mod h1:vR7hzQXu2zJy9AVAgeJqvqgH9Q5CA+iKCZ2gyEVpxRU=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
@@ -34,5 +28,5 @@ golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/tools v0.0.0-20190927191325-030b2cf1153e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/yaml.v2 v2.2.4 h1:/eiJrUcujPVeJ3xlSWaiNi3uSVmDGBK1pDHUHAnao1I=
+gopkg.in/yaml.v2 v2.2.7 h1:VUgggvou5XRW9mHwD/yXxIYSMtY0zoKQf/v226p2nyo=
-gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.2.7/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

main.go

@@ -60,9 +60,12 @@ func saveConfig() {
 }
 
 func hrDecode(x []byte) int {
+	if len(x) < 4 {
+		return 0
+	}
 	flags := x[0]
 	if flags&0x80 != 0 { // uint16 format
-		return int(binary.BigEndian.Uint16(x[1:2]))
+		return int(binary.BigEndian.Uint16(x[1:3]))
 	} else {
 		return int(x[1])
 	}
@@ -73,9 +76,9 @@ func eventloop() {
 		app.Size(unit.Dp(400), unit.Dp(400)),
 		app.Title("HRM"),
 	)
-	ble.Init() // allow ble driver to set up the JVM on Android
 	gofont.Register()
 	th := material.NewTheme()
+	th.TextSize = unit.Sp(fontSize)
 	gtx := &layout.Context{Queue: w.Queue()}
 
 	sysinset := &layout.Inset{}
@@ -88,6 +91,7 @@ func eventloop() {
 	margin := layout.UniformInset(unit.Dp(10))
 
 	b := ble.NewBLE()
+	b.Enable(w)
 
 	state := "starting"
 	var hr int
@@ -240,13 +244,15 @@ func eventloop() {
 				b.Scan()
 			case ble.DiscoverServiceEvent:
 				fmt.Printf("DiscoverService %s\n", e.Gatt.UUID)
-				if e.Gatt.UUID == "180D" {
+				//if e.Gatt.UUID == "180D" {
+				if e.Gatt.IsHRM() {
 					fmt.Printf("Found HRM Service\n")
 					e.Peripheral.DiscoverCharacteristics(e.Service)
 				}
 			case ble.DiscoverCharacteristicEvent:
 				fmt.Printf("DiscoverCharacteristic %s\n", e.Gatt.UUID)
-				if e.Gatt.UUID == "2A37" {
+				//if e.Gatt.UUID == "2A37" {
+				if e.Gatt.IsHRV() {
 					fmt.Printf("Found heart rate value\n")
 					e.Peripheral.SetNotifyValue(e.Characteristic)
 				}

os_android.go

@@ -1,15 +1,21 @@
 package main
 
 import (
+	"log"
+
 	"gioui.org/app"
 )
 
 var confDir string
+var fontSize float32 = 24
 
 func getConfDir() string {
-	if confDir != "" {
+	if confDir == "" {
-		return confDir
+		var err error
-	}
+		confDir,err = app.DataDir()
-	confDir,_ = app.DataDir()
+		if err != nil {
+			log.Fatal("Cannot get configuration directory")
+		}
+	}
 	return confDir
 }

os_darwin.go

@@ -8,6 +8,7 @@ import (
 )
 
 var confDir string
+var fontSize float32 = 16
 
 func getConfDir() string {
 	if confDir != "" {