commit 4662308fd0a7aa8fb5aca7c58da71b7e0bfc1c69
Author: Javier Peletier <jm@epiclabs.io>
Date:   Fri Dec 11 15:39:11 2020 +0100

    initial commit

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..af357d2
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+koolnova2mqtt
+.vscode/launch.json
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..2156a18
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,11 @@
+module koolnova2mqtt
+
+go 1.14
+
+require (
+	github.com/eclipse/paho.mqtt.golang v1.3.0
+	github.com/epiclabs-io/diff3 v0.0.0-20181217103619-05282cece609 // indirect
+	github.com/epiclabs-io/ut v0.0.0-20190416122157-8da7fe4b4947
+	github.com/goburrow/modbus v0.1.0
+	github.com/goburrow/serial v0.1.0 // indirect
+)
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..c4bb734
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,18 @@
+github.com/eclipse/paho.mqtt.golang v1.3.0 h1:MU79lqr3FKNKbSrGN7d7bNYqh8MwWW7Zcx0iG+VIw9I=
+github.com/eclipse/paho.mqtt.golang v1.3.0/go.mod h1:eTzb4gxwwyWpqBUHGQZ4ABAV7+Jgm1PklsYT/eo8Hcc=
+github.com/epiclabs-io/diff3 v0.0.0-20181217103619-05282cece609 h1:KHcpmcC/8cnCDXDm6SaCTajWF/vyUbBE1ovA27xYYEY=
+github.com/epiclabs-io/diff3 v0.0.0-20181217103619-05282cece609/go.mod h1:tM499ZoH5jQRF3wlMnl59SJQwVYXIBdJRZa/K71p0IM=
+github.com/epiclabs-io/ut v0.0.0-20190416122157-8da7fe4b4947 h1:5jyZq+mwwE90FnIyzAorlWF0Nrg8AB48KsDxofSAyBw=
+github.com/epiclabs-io/ut v0.0.0-20190416122157-8da7fe4b4947/go.mod h1:Sm6PW7b/nLOHEn3XxuUOXFYA4xFkLUnyAWUOcTGcRZ4=
+github.com/goburrow/modbus v0.1.0 h1:DejRZY73nEM6+bt5JSP6IsFolJ9dVcqxsYbpLbeW/ro=
+github.com/goburrow/modbus v0.1.0/go.mod h1:Kx552D5rLIS8E7TyUwQ/UdHEqvX5T8tyiGBTlzMcZBg=
+github.com/goburrow/serial v0.1.0 h1:v2T1SQa/dlUqQiYIT8+Cu7YolfqAi3K96UmhwYyuSrA=
+github.com/goburrow/serial v0.1.0/go.mod h1:sAiqG0nRVswsm1C97xsttiYCzSLBmUZ/VSlVLZJ8haA=
+github.com/gorilla/websocket v1.4.2 h1:+/TMaTYc4QFitKJxsQ7Yye35DkWvkdLcvGKqM+x0Ufc=
+github.com/gorilla/websocket v1.4.2/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/net v0.0.0-20200425230154-ff2c4b7c35a0 h1:Jcxah/M+oLZ/R4/z5RzfPzGbPXnVDPkEDtf2JnuxN+U=
+golang.org/x/net v0.0.0-20200425230154-ff2c4b7c35a0/go.mod h1:qpuaurCH72eLCgpAm/N6yyVIVM9cpaDIP3A8BGJEC5A=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..fa96421
--- /dev/null
+++ b/main.go
@@ -0,0 +1,154 @@
+package main
+
+import (
+	"crypto/tls"
+	"flag"
+	"fmt"
+	"koolnova2mqtt/watcher"
+	"koolnova2mqtt/zonewatcher"
+	"log"
+	"os"
+	"os/signal"
+	"strconv"
+	"syscall"
+	"time"
+
+	MQTT "github.com/eclipse/paho.mqtt.golang"
+	"github.com/goburrow/modbus"
+)
+
+const NUM_ZONES = 16
+
+func buildReader(handler *modbus.RTUClientHandler, client modbus.Client) watcher.ReadRegister {
+	return func(slaveID byte, address uint16, quantity uint16) (results []byte, err error) {
+		handler.SlaveId = slaveID
+		results, err = client.ReadHoldingRegisters(address-1, quantity)
+		return results, err
+	}
+}
+
+func getActiveZones(w zonewatcher.Watcher) ([]*zonewatcher.ZoneWatcher, error) {
+	var zones []*zonewatcher.ZoneWatcher
+
+	for n := 0; n < NUM_ZONES; n++ {
+		zone := zonewatcher.New(&zonewatcher.Config{
+			Zone:    n,
+			Watcher: w,
+		})
+		isPresent, err := zone.IsPresent()
+		if err != nil {
+			return nil, err
+		}
+		if isPresent {
+			zones = append(zones, zone)
+			temp, _ := zone.GetCurrentTemperature()
+			fmt.Printf("Zone %d is present. Temperature %g ºC\n", zone.Zone, temp)
+		}
+	}
+	return zones, nil
+}
+
+func main() {
+
+	c := make(chan os.Signal, 1)
+	signal.Notify(c, os.Interrupt, syscall.SIGTERM)
+
+	hostname, _ := os.Hostname()
+
+	server := flag.String("server", "tcp://127.0.0.1:1883", "The full url of the MQTT server to connect to ex: tcp://127.0.0.1:1883")
+	//topic := flag.String("topic", "#", "Topic to subscribe to")
+	//qos := flag.Int("qos", 0, "The QoS to subscribe to messages at")
+	clientid := flag.String("clientid", hostname+strconv.Itoa(time.Now().Second()), "A clientid for the connection")
+	username := flag.String("username", "", "A username to authenticate to the MQTT server")
+	password := flag.String("password", "", "Password to match username")
+	prefix := flag.String("prefix", "koolnova2mqtt", "MQTT topic root where to publish/read topics")
+	flag.Parse()
+
+	// Modbus RTU/ASCII
+	handler := modbus.NewRTUClientHandler("/dev/remserial1")
+	handler.BaudRate = 9600
+	handler.DataBits = 8
+	handler.Parity = "E"
+	handler.StopBits = 1
+	handler.SlaveId = 49
+	handler.Timeout = 5 * time.Second
+
+	err := handler.Connect()
+	if err != nil {
+		fmt.Println(err)
+	}
+	defer handler.Close()
+
+	client := modbus.NewClient(handler)
+
+	nodeName := "topFloors"
+
+	getTopic := func(zoneNum int, subtopic string) string {
+		return fmt.Sprintf("%s/%s/zone%d/%s", *prefix, nodeName, zoneNum, subtopic)
+	}
+
+	w := watcher.New(&watcher.Config{
+		Address:      1,
+		Quantity:     64,
+		RegisterSize: 2,
+		SlaveID:      49,
+		Read:         buildReader(handler, client),
+	})
+
+	err = w.Poll()
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	zones, err := getActiveZones(w)
+
+	connOpts := MQTT.NewClientOptions().AddBroker(*server).SetClientID(*clientid).SetCleanSession(true)
+	if *username != "" {
+		connOpts.SetUsername(*username)
+		if *password != "" {
+			connOpts.SetPassword(*password)
+		}
+	}
+	tlsConfig := &tls.Config{InsecureSkipVerify: true, ClientAuth: tls.NoClientCert}
+	connOpts.SetTLSConfig(tlsConfig)
+
+	connOpts.OnConnect = func(c MQTT.Client) {
+		/* 		if token := c.Subscribe(*topic, byte(*qos), onMessageReceived); token.Wait() && token.Error() != nil {
+			panic(token.Error())
+		} */
+		w.TriggerCallbacks()
+	}
+
+	mqttClient := MQTT.NewClient(connOpts)
+
+	for _, zone := range zones {
+		zone := zone
+		zone.OnCurrentTempChange = func(currentTemp float32) {
+			mqttClient.Publish(getTopic(zone.Zone, "currentTemperature"), 0, false, fmt.Sprintf("%g", currentTemp))
+		}
+		zone.OnTargetTempChange = func(targetTemp float32) {
+			mqttClient.Publish(getTopic(zone.Zone, "targetTemperature"), 0, false, fmt.Sprintf("%g", targetTemp))
+		}
+	}
+
+	if token := mqttClient.Connect(); token.Wait() && token.Error() != nil {
+		panic(token.Error())
+	} else {
+		fmt.Printf("Connected to %s\n", *server)
+	}
+
+	ticker := time.NewTicker(time.Second)
+
+	go func() {
+		for range ticker.C {
+			err := w.Poll()
+			if err != nil {
+				log.Printf("Error polling modbus: %s\n", err)
+			}
+		}
+	}()
+
+	<-c
+
+}
diff --git a/watcher/watcher.go b/watcher/watcher.go
new file mode 100644
index 0000000..c9506c7
--- /dev/null
+++ b/watcher/watcher.go
@@ -0,0 +1,91 @@
+package watcher
+
+import (
+	"bytes"
+	"errors"
+)
+
+type ReadRegister func(slaveID byte, address uint16, quantity uint16) (results []byte, err error)
+
+type Config struct {
+	Address      uint16
+	Quantity     uint16
+	SlaveID      byte
+	Read         ReadRegister
+	RegisterSize int
+}
+
+type watcher struct {
+	Config
+	state     []byte
+	callbacks map[uint16]func(address uint16)
+}
+
+var ErrIncorrectRegisterSize = errors.New("Incorrect register size")
+var ErrAddressOutOfRange = errors.New("Register address out of range")
+var ErrUninitialized = errors.New("State uninitialized. Call Poll() first.")
+
+func New(config *Config) *watcher {
+	return &watcher{
+		Config:    *config,
+		callbacks: make(map[uint16]func(address uint16)),
+	}
+}
+
+func (w *watcher) RegisterCallback(address uint16, callback func(address uint16)) {
+	w.callbacks[address] = callback
+}
+
+func (w *watcher) Poll() error {
+	newState, err := w.Read(w.SlaveID, w.Address, w.Quantity)
+	if err != nil {
+		return err
+	}
+
+	if len(newState) != int(w.Quantity)*w.RegisterSize {
+		return ErrIncorrectRegisterSize
+	}
+
+	oldState := w.state
+	w.state = newState
+
+	first := len(oldState) != len(newState)
+	address := w.Address
+	for n := 0; n < len(newState); n += w.RegisterSize {
+		callback := w.callbacks[address]
+		if callback == nil {
+			address++
+			continue
+		}
+		var oldValue []byte
+		newValue := newState[n : n+w.RegisterSize]
+		if first {
+			oldValue = nil
+		} else {
+			oldValue = oldState[n : n+w.RegisterSize]
+		}
+		if bytes.Compare(oldValue, newValue) != 0 {
+			callback(address)
+		}
+		address++
+	}
+	return nil
+}
+
+func (w *watcher) ReadRegister(address uint16) (value []byte, err error) {
+	if address < w.Address || address > w.Address+uint16(w.Quantity) {
+		return nil, ErrAddressOutOfRange
+	}
+	if w.state == nil {
+		return nil, ErrUninitialized
+	}
+	registerOffset := int(address-w.Address) * w.RegisterSize
+	return w.state[registerOffset : registerOffset+w.RegisterSize], nil
+
+}
+
+func (w *watcher) TriggerCallbacks() {
+	for address, callback := range w.callbacks {
+		callback(address)
+	}
+}
diff --git a/watcher/watcher_test.go b/watcher/watcher_test.go
new file mode 100644
index 0000000..a2ab4ee
--- /dev/null
+++ b/watcher/watcher_test.go
@@ -0,0 +1,87 @@
+package watcher_test
+
+import (
+	"errors"
+	"koolnova2mqtt/watcher"
+	"testing"
+
+	"github.com/epiclabs-io/ut"
+)
+
+func TestWatcher(tx *testing.T) {
+	t := ut.BeginTest(tx, false)
+	defer t.FinishTest()
+
+	var r []byte
+	var readRegisterError error = nil
+	readRegister := func(slaveID byte, address uint16, quantity uint16) (results []byte, err error) {
+		return r, readRegisterError
+	}
+
+	w := watcher.New(&watcher.Config{
+		Address:      1000,
+		Quantity:     5,
+		RegisterSize: 2,
+		SlaveID:      1,
+		Read:         readRegister,
+	})
+
+	var cbAddress uint16
+	var callbackCount int
+	w.RegisterCallback(1000, func(address uint16) {
+		cbAddress = address
+		callbackCount++
+	})
+
+	w.RegisterCallback(1004, func(address uint16) {
+		callbackCount++
+	})
+
+	r = []byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
+
+	value, err := w.ReadRegister(1001)
+	t.MustFailWith(err, watcher.ErrUninitialized)
+	t.Equals([]byte(nil), value)
+
+	err = w.Poll()
+	t.Ok(err)
+	t.Equals(2, callbackCount)
+
+	value, err = w.ReadRegister(1001)
+	t.Ok(err)
+	t.Equals([]byte{3, 4}, value)
+
+	_, err = w.ReadRegister(200)
+	t.MustFailWith(err, watcher.ErrAddressOutOfRange)
+
+	_, err = w.ReadRegister(5000)
+	t.MustFailWith(err, watcher.ErrAddressOutOfRange)
+
+	callbackCount = 0
+	err = w.Poll()
+	t.Ok(err)
+
+	t.Equals(callbackCount, 0)
+
+	r = []byte{79, 82, 3, 4, 5, 6, 7, 8, 9, 10}
+	callbackCount = 0
+	err = w.Poll()
+	t.Ok(err)
+
+	t.Equals(1, callbackCount)
+	t.Equals(uint16(1000), cbAddress)
+
+	cbNewValue, err := w.ReadRegister(cbAddress)
+	t.Ok(err)
+	t.Equals([]byte{79, 82}, cbNewValue)
+
+	r = []byte{1, 2}
+	err = w.Poll()
+	t.MustFailWith(err, watcher.ErrIncorrectRegisterSize)
+
+	readRegisterError = errors.New("error")
+
+	err = w.Poll()
+	t.MustFail(err, "expected Poll() to fail if readRegister returns error")
+
+}
diff --git a/zonewatcher/zonewatcher.go b/zonewatcher/zonewatcher.go
new file mode 100644
index 0000000..552ce67
--- /dev/null
+++ b/zonewatcher/zonewatcher.go
@@ -0,0 +1,109 @@
+package zonewatcher
+
+import (
+	"encoding/binary"
+	"log"
+)
+
+const REG_PER_ZONE = 4
+const REG_ENABLED = 1
+const REG_MODE = 2
+const REG_TARGET_TEMP = 3
+const REG_CURRENT_TEMP = 4
+
+type Watcher interface {
+	ReadRegister(address uint16) (value []byte, err error)
+	RegisterCallback(address uint16, callback func(address uint16))
+}
+
+type Config struct {
+	Zone    int
+	Watcher Watcher
+}
+
+type ZoneWatcher struct {
+	Config
+	OnCurrentTempChange func(newTemp float32)
+	OnTargetTempChange  func(newTemp float32)
+}
+
+func New(config *Config) *ZoneWatcher {
+	zw := &ZoneWatcher{
+		Config: *config,
+	}
+	zw.RegisterCallback(REG_CURRENT_TEMP, func() {
+		if zw.OnCurrentTempChange == nil {
+			return
+		}
+
+		temp, err := zw.GetCurrentTemperature()
+		if err != nil {
+			log.Printf("Cannot read current temperature: %s\n", err)
+			return
+		}
+		zw.OnCurrentTempChange(temp)
+	})
+	zw.RegisterCallback(REG_TARGET_TEMP, func() {
+		if zw.OnTargetTempChange == nil {
+			return
+		}
+
+		temp, err := zw.GetTargetTemperature()
+		if err != nil {
+			log.Printf("Cannot read target temperature: %s\n", err)
+			return
+		}
+		zw.OnTargetTempChange(temp)
+	})
+	return zw
+}
+
+func (zw *ZoneWatcher) RegisterCallback(num int, f func()) {
+	zw.Watcher.RegisterCallback(uint16(zw.Zone*REG_PER_ZONE+num), func(address uint16) {
+		f()
+	})
+}
+
+func (zw *ZoneWatcher) ReadRegister(num int) (uint16, error) {
+
+	b, err := zw.Watcher.ReadRegister(uint16(zw.Zone*REG_PER_ZONE + num))
+	if err != nil {
+		return 0, err
+	}
+	return binary.BigEndian.Uint16(b), nil
+}
+
+func (zw *ZoneWatcher) IsOn() (bool, error) {
+	r1, err := zw.ReadRegister(REG_ENABLED)
+	if err != nil {
+		return false, err
+	}
+
+	return r1&uint16(0x1) != 0, nil
+}
+
+func (zw *ZoneWatcher) IsPresent() (bool, error) {
+	r1, err := zw.ReadRegister(REG_ENABLED)
+	if err != nil {
+		return false, err
+	}
+
+	return r1&uint16(0x2) != 0, nil
+}
+
+func (zw *ZoneWatcher) GetCurrentTemperature() (float32, error) {
+	r4, err := zw.ReadRegister(REG_CURRENT_TEMP)
+	if err != nil {
+		return 0.0, err
+	}
+
+	return float32(r4) / 2.0, nil
+}
+
+func (zw *ZoneWatcher) GetTargetTemperature() (float32, error) {
+	r3, err := zw.ReadRegister(REG_TARGET_TEMP)
+	if err != nil {
+		return 0.0, err
+	}
+	return float32(r3) / 2.0, nil
+}