release: prepare for v0.8.0

Signed-off-by: Ron Evans <ron@hybridgroup.com>

CHANGELOG.md

@@ -1,3 +1,16 @@
+0.8.0
+---
+- **new devices**
+    - mcp3008: add implementation for MCP3008 ADC with SPI interface
+    - semihosting: initial implementation of ARM semihosting
+- **enhancements**
+    - espat: refactor response processing for greater speed and efficiency
+    - espat: implement mqtt subscribe functionality via blocking select/channels (experiemental)
+- **bugfixes**
+    - st7789: fix index out of bounds error
+- **examples**
+    - Add espat driver example for mqtt subscribe
+
 0.7.0
 ---
 - **new devices**

Makefile

@@ -31,6 +31,7 @@ smoke-test:
 	tinygo build -size short -o ./build/test.elf -target=circuitplay-express ./examples/lis3dh/main.go
 	tinygo build -size short -o ./build/test.elf -target=arduino-nano33 ./examples/lsm6ds3/main.go
 	tinygo build -size short -o ./build/test.elf -target=itsybitsy-m0 ./examples/mag3110/main.go
+	tinygo build -size short -o ./build/test.elf -target=itsybitsy-m0 ./examples/mcp3008/main.go
 	tinygo build -size short -o ./build/test.elf -target=microbit ./examples/microbitmatrix/main.go
 	tinygo build -size short -o ./build/test.elf -target=itsybitsy-m0 ./examples/mma8653/main.go
 	tinygo build -size short -o ./build/test.elf -target=itsybitsy-m0 ./examples/mpu6050/main.go

README.md

@@ -52,6 +52,8 @@ func main() {
 
 ## Currently supported devices
 
+The following 34 devices are supported.
+
 | Device Name | Interface Type |
 |----------|-------------|
 | [ADXL345 accelerometer](http://www.analog.com/media/en/technical-documentation/data-sheets/ADXL345.pdf) | I2C |
@@ -71,6 +73,7 @@ func main() {
 | [LIS3DH accelerometer](https://www.st.com/resource/en/datasheet/lis3dh.pdf) | I2C |
 | [LSM6DS3 accelerometer](https://www.st.com/resource/en/datasheet/lsm6ds3.pdf) | I2C |
 | [MAG3110 magnetometer](https://www.nxp.com/docs/en/data-sheet/MAG3110.pdf) | I2C |
+| [MCP3008 analog to digital converter (ADC)](http://ww1.microchip.com/downloads/en/DeviceDoc/21295d.pdf) | SPI |
 | [BBC micro:bit LED matrix](https://github.com/bbcmicrobit/hardware/blob/master/SCH_BBC-Microbit_V1.3B.pdf) | GPIO |
 | [Microphone - PDM](https://cdn-learn.adafruit.com/assets/assets/000/049/977/original/MP34DT01-M.pdf) | I2S/PDM |
 | [MMA8653 accelerometer](https://www.nxp.com/docs/en/data-sheet/MMA8653FC.pdf) | I2C |

espat/espat.go

@@ -19,6 +19,7 @@
 package espat // import "tinygo.org/x/drivers/espat"
 
 import (
+	"errors"
 	"machine"
 	"strconv"
 	"strings"
@@ -54,11 +55,11 @@ func (d *Device) Connected() bool {
 	d.Execute(Test)
 
 	// handle response here, should include "OK"
-	r := d.Response(100)
-	if strings.Contains(string(r), "OK") {
-		return true
+	_, err := d.Response(100)
+	if err != nil {
+		return false
 	}
-	return false
+	return true
 }
 
 // Write raw bytes to the UART.
@@ -72,7 +73,7 @@ func (d *Device) Read(b []byte) (n int, err error) {
 }
 
 // how long in milliseconds to pause after sending AT commands
-const pause = 100
+const pause = 300
 
 // Execute sends an AT command to the ESP8266/ESP32.
 func (d Device) Execute(cmd string) error {
@@ -97,7 +98,11 @@ func (d Device) Set(cmd, params string) error {
 // Version returns the ESP8266/ESP32 firmware version info.
 func (d Device) Version() []byte {
 	d.Execute(Version)
-	return d.Response(100)
+	r, err := d.Response(100)
+	if err != nil {
+		return []byte("unknown")
+	}
+	return r
 }
 
 // Echo sets the ESP8266/ESP32 echo setting.
@@ -122,7 +127,7 @@ func (d Device) Reset() {
 // ReadSocket returns the data that has already been read in from the responses.
 func (d *Device) ReadSocket(b []byte) (n int, err error) {
 	// make sure no data in buffer
-	d.Response(100)
+	d.Response(300)
 
 	count := len(b)
 	if len(b) >= len(d.socketdata) {
@@ -142,118 +147,73 @@ func (d *Device) ReadSocket(b []byte) (n int, err error) {
 
 // Response gets the next response bytes from the ESP8266/ESP32.
 // The call will retry for up to timeout milliseconds before returning nothing.
-func (d *Device) Response(timeout int) []byte {
-	var i int
-	pause := 10 // pause to wait for 10 ms
+func (d *Device) Response(timeout int) ([]byte, error) {
+	// read data
+	var size int
+	var start, end int
+	pause := 100 // pause to wait for 100 ms
 	retries := timeout / pause
 
-	header := make([]byte, 2)
 	for {
-		for d.bus.Buffered() > 0 {
-			// get the first 2 bytes
-			header[0], _ = d.bus.ReadByte()
-			header[1], _ = d.bus.ReadByte()
+		size = d.bus.Buffered()
 
-			if d.isLeadingCRLF(header) {
-				// skip it
-				header[0], _ = d.bus.ReadByte()
-				header[1], _ = d.bus.ReadByte()
+		if size > 0 {
+			end += size
+			d.bus.Read(d.response[start:end])
+
+			// if "+IPD" then read socket data
+			if strings.Contains(string(d.response[:end]), "+IPD") {
+				// handle socket data
+				return nil, d.parseIPD(end)
 			}
 
-			if d.isIPD(header) {
-				// is socket data packet
-				d.parseIPD()
-			} else {
-				// no, so put into response
-				d.response[i] = header[0]
-				i++
-				d.response[i] = header[1]
-				i++
+			// if "OK" then the command worked
+			if strings.Contains(string(d.response[:end]), "OK") {
+				return d.response[start:end], nil
 			}
 
-			// read the rest of normal command response
-			for d.bus.Buffered() > 0 {
-				data, err := d.bus.ReadByte()
-				if err != nil {
-					return nil
-				}
-				d.response[i] = data
-				i++
+			// if "Error" then the command failed
+			if strings.Contains(string(d.response[:end]), "ERROR") {
+				return d.response[start:end], errors.New("response error:" + string(d.response[start:end]))
 			}
+
+			// if anything else, then keep reading data in?
+			start = end
 		}
+
+		// wait longer?
 		retries--
 		if retries == 0 {
-			break
+			return nil, errors.New("response timeout error:" + string(d.response[start:end]))
 		}
 
-		// pause to make sure is no more data to be read
 		time.Sleep(time.Duration(pause) * time.Millisecond)
 	}
-	return d.response[:i]
 }
 
-func (d *Device) isLeadingCRLF(b []byte) bool {
-	if len(b) < 2 {
-		return false
-	}
-	if b[0] == 13 && b[1] == 10 {
-		return true
-	}
-	return false
-}
+func (d *Device) parseIPD(end int) error {
+	// find the "+IPD," to get length
+	s := strings.Index(string(d.response[:end]), "+IPD,")
 
-func (d *Device) isIPD(b []byte) bool {
-	if len(b) < 2 {
-		return false
-	}
-	if b[0] == '+' && b[1] == 'I' {
-		return true
-	}
-	return false
-}
+	// find the ":"
+	e := strings.Index(string(d.response[:end]), ":")
 
-func (d *Device) parseIPD() bool {
-	data, _ := d.bus.ReadByte()
-	if data != 'P' {
-		// error
-		return false
-	}
-	data, _ = d.bus.ReadByte()
-	if data != 'D' {
-		// error
-		return false
-	}
-	data, _ = d.bus.ReadByte()
-	if data != ',' {
-		// error
-		return false
-	}
+	// find the data length
+	val := string(d.response[s+5 : e])
 
-	// get the expected data length
-	// skip remaining header up to the ":"
-	buf := []byte{}
-	data, _ = d.bus.ReadByte()
-	for data != ':' {
-		// put into the buffer with int value here
-		buf = append(buf, data)
-
-		// read next value
-		data, _ = d.bus.ReadByte()
-	}
-
-	val := string(buf)
-	count, err := strconv.Atoi(val)
+	// TODO: verify count
+	_, err := strconv.Atoi(val)
 	if err != nil {
 		// not expected data here. what to do?
-		return false
+		return err
 	}
 
 	// load up the socket data
-	// only read the expected amount of data
-	for m := 0; m < count; m++ {
-		data, _ = d.bus.ReadByte()
-		d.socketdata = append(d.socketdata, data)
-	}
-
-	return true
+	d.socketdata = append(d.socketdata, d.response[e+1:end]...)
+	return nil
+}
+
+// IsSocketDataAvailable returns of there is socket data available
+func (d *Device) IsSocketDataAvailable() bool {
+	return len(d.socketdata) > 0 || d.bus.Buffered() > 0
 }

espat/mqtt/mqtt.go

@@ -19,15 +19,21 @@ import (
 // connection) are created before the application is actually ready.
 func NewClient(o *ClientOptions) Client {
 	c := &mqttclient{opts: o, adaptor: o.Adaptor}
+	c.msgRouter, c.stopRouter = newRouter()
 	return c
 }
 
 type mqttclient struct {
-	adaptor   *espat.Device
-	conn      net.Conn
-	connected bool
-	opts      *ClientOptions
-	mid       uint16
+	adaptor         *espat.Device
+	conn            net.Conn
+	connected       bool
+	opts            *ClientOptions
+	mid             uint16
+	inbound         chan packets.ControlPacket
+	stop            chan struct{}
+	msgRouter       *router
+	stopRouter      chan bool
+	incomingPubChan chan *packets.PublishPacket
 }
 
 // AddRoute allows you to add a handler for messages on a specific topic
@@ -71,6 +77,12 @@ func (c *mqttclient) Connect() Token {
 		return &mqtttoken{err: errors.New("invalid protocol")}
 	}
 
+	c.mid = 1
+	c.inbound = make(chan packets.ControlPacket)
+	c.stop = make(chan struct{})
+	c.incomingPubChan = make(chan *packets.PublishPacket)
+	c.msgRouter.matchAndDispatch(c.incomingPubChan, c.opts.Order, c)
+
 	// send the MQTT connect message
 	connectPkt := packets.NewControlPacket(packets.Connect).(*packets.ConnectPacket)
 	connectPkt.Qos = 0
@@ -84,7 +96,7 @@ func (c *mqttclient) Connect() Token {
 		connectPkt.PasswordFlag = true
 	}
 
-	connectPkt.ClientIdentifier = c.opts.ClientID //"tinygo-client-" + randomString(10)
+	connectPkt.ClientIdentifier = c.opts.ClientID
 	connectPkt.ProtocolVersion = byte(c.opts.ProtocolVersion)
 	connectPkt.ProtocolName = "MQTT"
 	connectPkt.Keepalive = 30
@@ -94,26 +106,25 @@ func (c *mqttclient) Connect() Token {
 		return &mqtttoken{err: err}
 	}
 
-	// TODO: handle timeout
-	for {
-		packet, _ := packets.ReadPacket(c.conn)
-
-		if packet != nil {
-			ack, ok := packet.(*packets.ConnackPacket)
-			if ok {
-				if ack.ReturnCode == 0 {
-					// success
-					return &mqtttoken{}
-				}
-				// otherwise something went wrong
+	// TODO: handle timeout as ReadPacket blocks until it gets a packet.
+	// CONNECT response.
+	packet, err := packets.ReadPacket(c.conn)
+	if err != nil {
+		return &mqtttoken{err: err}
+	}
+	if packet != nil {
+		ack, ok := packet.(*packets.ConnackPacket)
+		if ok {
+			if ack.ReturnCode != 0 {
 				return &mqtttoken{err: errors.New(packet.String())}
 			}
+			c.connected = true
 		}
-
-		time.Sleep(100 * time.Millisecond)
 	}
 
-	c.connected = true
+	go readMessages(c)
+	go processInbound(c)
+
 	return &mqtttoken{}
 }
 
@@ -129,6 +140,10 @@ func (c *mqttclient) Disconnect(quiesce uint) {
 // to the specified topic.
 // Returns a token to track delivery of the message to the broker
 func (c *mqttclient) Publish(topic string, qos byte, retained bool, payload interface{}) Token {
+	if !c.IsConnected() {
+		return &mqtttoken{err: errors.New("MQTT client not connected")}
+	}
+
 	pub := packets.NewControlPacket(packets.Publish).(*packets.PublishPacket)
 	pub.Qos = qos
 	pub.TopicName = topic
@@ -144,12 +159,37 @@ func (c *mqttclient) Publish(topic string, qos byte, retained bool, payload inte
 	c.mid++
 
 	err := pub.Write(c.conn)
-	return &mqtttoken{err: err}
+	if err != nil {
+		return &mqtttoken{err: err}
+	}
+
+	return &mqtttoken{}
 }
 
 // Subscribe starts a new subscription. Provide a MessageHandler to be executed when
 // a message is published on the topic provided.
 func (c *mqttclient) Subscribe(topic string, qos byte, callback MessageHandler) Token {
+	if !c.IsConnected() {
+		return &mqtttoken{err: errors.New("MQTT client not connected")}
+	}
+
+	sub := packets.NewControlPacket(packets.Subscribe).(*packets.SubscribePacket)
+	sub.Topics = append(sub.Topics, topic)
+	sub.Qoss = append(sub.Qoss, qos)
+
+	if callback != nil {
+		c.msgRouter.addRoute(topic, callback)
+	}
+
+	sub.MessageID = c.mid
+	c.mid++
+
+	// drop in the channel to send
+	err := sub.Write(c.conn)
+	if err != nil {
+		return &mqtttoken{err: err}
+	}
+
 	return &mqtttoken{}
 }
 
@@ -173,18 +213,92 @@ func (c *mqttclient) OptionsReader() ClientOptionsReader {
 	return r
 }
 
-type mqtttoken struct {
-	err error
+func processInbound(c *mqttclient) {
+	for {
+		select {
+		case msg := <-c.inbound:
+			switch m := msg.(type) {
+			case *packets.PingrespPacket:
+				// TODO: handle this
+			case *packets.SubackPacket:
+				// TODO: handle this
+			case *packets.UnsubackPacket:
+				// TODO: handle this
+			case *packets.PublishPacket:
+				// TODO: handle Qos
+				c.incomingPubChan <- m
+			case *packets.PubackPacket:
+				// TODO: handle this
+			case *packets.PubrecPacket:
+				// TODO: handle this
+			case *packets.PubrelPacket:
+				// TODO: handle this
+			case *packets.PubcompPacket:
+				// TODO: handle this
+			}
+		case <-c.stop:
+			return
+		}
+	}
 }
 
-func (t *mqtttoken) Wait() bool {
-	return true
+// readMessages reads incoming messages off the wire.
+// incoming messages are then send into inbound channel.
+func readMessages(c *mqttclient) {
+	var err error
+	var cp packets.ControlPacket
+
+PROCESS:
+	for {
+		if cp, err = c.ReadPacket(); err != nil {
+			break PROCESS
+		}
+		if cp != nil {
+			c.inbound <- cp
+			// TODO: Notify keepalive logic that we recently received a packet
+		}
+
+		time.Sleep(100 * time.Millisecond)
+	}
+
+	// TODO: handle if we received an error on read.
+	// If disconnect is in progress, swallow error and return
 }
 
-func (t *mqtttoken) WaitTimeout(time.Duration) bool {
-	return true
+func (c *mqttclient) ackFunc(packet *packets.PublishPacket) func() {
+	return func() {
+		switch packet.Qos {
+		case 2:
+			// pr := packets.NewControlPacket(packets.Pubrec).(*packets.PubrecPacket)
+			// pr.MessageID = packet.MessageID
+			// DEBUG.Println(NET, "putting pubrec msg on obound")
+			// select {
+			// case c.oboundP <- &PacketAndToken{p: pr, t: nil}:
+			// case <-c.stop:
+			// }
+			// DEBUG.Println(NET, "done putting pubrec msg on obound")
+		case 1:
+			// pa := packets.NewControlPacket(packets.Puback).(*packets.PubackPacket)
+			// pa.MessageID = packet.MessageID
+			// DEBUG.Println(NET, "putting puback msg on obound")
+			// persistOutbound(c.persist, pa)
+			// select {
+			// case c.oboundP <- &PacketAndToken{p: pa, t: nil}:
+			// case <-c.stop:
+			// }
+			// DEBUG.Println(NET, "done putting puback msg on obound")
+		case 0:
+			// do nothing, since there is no need to send an ack packet back
+		}
+	}
 }
 
-func (t *mqtttoken) Error() error {
-	return t.err
+// ReadPacket tries to read the next incoming packet from the MQTT broker.
+// If there is no data yet but also is no error, it returns nil for both values.
+func (c *mqttclient) ReadPacket() (packets.ControlPacket, error) {
+	// check for data first...
+	if espat.ActiveDevice.IsSocketDataAvailable() {
+		return packets.ReadPacket(c.conn)
+	}
+	return nil, nil
 }

espat/mqtt/paho.go

@@ -24,6 +24,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/eclipse/paho.mqtt.golang/packets"
 	"tinygo.org/x/drivers/espat"
 )
 
@@ -155,6 +156,18 @@ func (m *message) Ack() {
 	return
 }
 
+func messageFromPublish(p *packets.PublishPacket, ack func()) Message {
+	return &message{
+		duplicate: p.Dup,
+		qos:       p.Qos,
+		retained:  p.Retain,
+		topic:     p.TopicName,
+		messageID: p.MessageID,
+		payload:   p.Payload,
+		ack:       ack,
+	}
+}
+
 // ClientOptionsReader provides an interface for reading ClientOptions after the client has been initialized.
 type ClientOptionsReader struct {
 	options *ClientOptions

espat/mqtt/router.go

@@ -0,0 +1,182 @@
+// The following code is a slightly modified version of code taken from the Paho MQTT library.
+// It is here until TinyGo can compile the "net" package from the standard library, at which time
+// it can be removed.
+
+/*
+ * Copyright (c) 2013 IBM Corp.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *    Seth Hoenig
+ *    Allan Stockdill-Mander
+ *    Mike Robertson
+ */
+
+package mqtt
+
+import (
+	"container/list"
+	"strings"
+
+	"github.com/eclipse/paho.mqtt.golang/packets"
+)
+
+// route is a type which associates MQTT Topic strings with a
+// callback to be executed upon the arrival of a message associated
+// with a subscription to that topic.
+type route struct {
+	topic    string
+	callback MessageHandler
+}
+
+// match takes a slice of strings which represent the route being tested having been split on '/'
+// separators, and a slice of strings representing the topic string in the published message, similarly
+// split.
+// The function determines if the topic string matches the route according to the MQTT topic rules
+// and returns a boolean of the outcome
+func match(route []string, topic []string) bool {
+	if len(route) == 0 {
+		if len(topic) == 0 {
+			return true
+		}
+		return false
+	}
+
+	if len(topic) == 0 {
+		if route[0] == "#" {
+			return true
+		}
+		return false
+	}
+
+	if route[0] == "#" {
+		return true
+	}
+
+	if (route[0] == "+") || (route[0] == topic[0]) {
+		return match(route[1:], topic[1:])
+	}
+	return false
+}
+
+func routeIncludesTopic(route, topic string) bool {
+	return match(routeSplit(route), strings.Split(topic, "/"))
+}
+
+// removes $share and sharename when splitting the route to allow
+// shared subscription routes to correctly match the topic
+func routeSplit(route string) []string {
+	var result []string
+	if strings.HasPrefix(route, "$share") {
+		result = strings.Split(route, "/")[2:]
+	} else {
+		result = strings.Split(route, "/")
+	}
+	return result
+}
+
+// match takes the topic string of the published message and does a basic compare to the
+// string of the current Route, if they match it returns true
+func (r *route) match(topic string) bool {
+	return r.topic == topic || routeIncludesTopic(r.topic, topic)
+}
+
+type router struct {
+	//sync.RWMutex
+	routes         *list.List
+	defaultHandler MessageHandler
+	messages       chan *packets.PublishPacket
+	stop           chan bool
+}
+
+// newRouter returns a new instance of a Router and channel which can be used to tell the Router
+// to stop
+func newRouter() (*router, chan bool) {
+	router := &router{routes: list.New(), messages: make(chan *packets.PublishPacket), stop: make(chan bool)}
+	stop := router.stop
+	return router, stop
+}
+
+// addRoute takes a topic string and MessageHandler callback. It looks in the current list of
+// routes to see if there is already a matching Route. If there is it replaces the current
+// callback with the new one. If not it add a new entry to the list of Routes.
+func (r *router) addRoute(topic string, callback MessageHandler) {
+	for e := r.routes.Front(); e != nil; e = e.Next() {
+		if e.Value.(*route).match(topic) {
+			r := e.Value.(*route)
+			r.callback = callback
+			return
+		}
+	}
+	r.routes.PushBack(&route{topic: topic, callback: callback})
+}
+
+// deleteRoute takes a route string, looks for a matching Route in the list of Routes. If
+// found it removes the Route from the list.
+func (r *router) deleteRoute(topic string) {
+	for e := r.routes.Front(); e != nil; e = e.Next() {
+		if e.Value.(*route).match(topic) {
+			r.routes.Remove(e)
+			return
+		}
+	}
+}
+
+// setDefaultHandler assigns a default callback that will be called if no matching Route
+// is found for an incoming Publish.
+func (r *router) setDefaultHandler(handler MessageHandler) {
+	r.defaultHandler = handler
+}
+
+// matchAndDispatch takes a channel of Message pointers as input and starts a go routine that
+// takes messages off the channel, matches them against the internal route list and calls the
+// associated callback (or the defaultHandler, if one exists and no other route matched). If
+// anything is sent down the stop channel the function will end.
+func (r *router) matchAndDispatch(messages <-chan *packets.PublishPacket, order bool, client *mqttclient) {
+	go func() {
+		for {
+			select {
+			case message := <-messages:
+				sent := false
+				m := messageFromPublish(message, client.ackFunc(message))
+				handlers := []MessageHandler{}
+				for e := r.routes.Front(); e != nil; e = e.Next() {
+					if e.Value.(*route).match(message.TopicName) {
+						if order {
+							handlers = append(handlers, e.Value.(*route).callback)
+						} else {
+							hd := e.Value.(*route).callback
+							go func() {
+								hd(client, m)
+								//TODO: m.Ack()
+							}()
+						}
+						sent = true
+					}
+				}
+				if !sent && r.defaultHandler != nil {
+					if order {
+						handlers = append(handlers, r.defaultHandler)
+					} else {
+						go func() {
+							r.defaultHandler(client, m)
+							//TODO: m.Ack()
+						}()
+					}
+				}
+				for _, handler := range handlers {
+					func() {
+						handler(client, m)
+						//TODO: m.Ack()
+					}()
+				}
+			case <-r.stop:
+				return
+			}
+		}
+	}()
+}

espat/mqtt/token.go

@@ -0,0 +1,19 @@
+package mqtt
+
+import "time"
+
+type mqtttoken struct {
+	err error
+}
+
+func (t *mqtttoken) Wait() bool {
+	return true
+}
+
+func (t *mqtttoken) WaitTimeout(time.Duration) bool {
+	return true
+}
+
+func (t *mqtttoken) Error() error {
+	return t.err
+}

espat/net/net.go

@@ -23,7 +23,10 @@ func DialUDP(network string, laddr, raddr *UDPAddr) (*UDPSerialConn, error) {
 	espat.ActiveDevice.DisconnectSocket()
 
 	// connect new socket
-	espat.ActiveDevice.ConnectUDPSocket(addr, sendport, listenport)
+	err := espat.ActiveDevice.ConnectUDPSocket(addr, sendport, listenport)
+	if err != nil {
+		return nil, err
+	}
 
 	return &UDPSerialConn{SerialConn: SerialConn{Adaptor: espat.ActiveDevice}, laddr: laddr, raddr: raddr}, nil
 }
@@ -38,7 +41,10 @@ func ListenUDP(network string, laddr *UDPAddr) (*UDPSerialConn, error) {
 	espat.ActiveDevice.DisconnectSocket()
 
 	// connect new socket
-	espat.ActiveDevice.ConnectUDPSocket(addr, sendport, listenport)
+	err := espat.ActiveDevice.ConnectUDPSocket(addr, sendport, listenport)
+	if err != nil {
+		return nil, err
+	}
 
 	return &UDPSerialConn{SerialConn: SerialConn{Adaptor: espat.ActiveDevice}, laddr: laddr}, nil
 }
@@ -50,11 +56,14 @@ func DialTCP(network string, laddr, raddr *TCPAddr) (*TCPSerialConn, error) {
 	addr := raddr.IP.String()
 	sendport := strconv.Itoa(raddr.Port)
 
-	// disconnect any old socket
-	espat.ActiveDevice.DisconnectSocket()
+	// disconnect any old socket?
+	//espat.ActiveDevice.DisconnectSocket()
 
 	// connect new socket
-	espat.ActiveDevice.ConnectTCPSocket(addr, sendport)
+	err := espat.ActiveDevice.ConnectTCPSocket(addr, sendport)
+	if err != nil {
+		return nil, err
+	}
 
 	return &TCPSerialConn{SerialConn: SerialConn{Adaptor: espat.ActiveDevice}, laddr: laddr, raddr: raddr}, nil
 }
@@ -132,8 +141,19 @@ func (c *SerialConn) Read(b []byte) (n int, err error) {
 func (c *SerialConn) Write(b []byte) (n int, err error) {
 	// specify that is a data transfer to the
 	// currently open socket, not commands to the ESP8266/ESP32.
-	c.Adaptor.StartSocketSend(len(b))
-	return c.Adaptor.Write(b)
+	err = c.Adaptor.StartSocketSend(len(b))
+	if err != nil {
+		return
+	}
+	n, err = c.Adaptor.Write(b)
+	if err != nil {
+		return n, err
+	}
+	_, err = c.Adaptor.Response(1000)
+	if err != nil {
+		return n, err
+	}
+	return n, err
 }
 
 // Close closes the connection.

espat/tcp.go

@@ -17,7 +17,14 @@ const (
 // GetDNS returns the IP address for a domain name.
 func (d *Device) GetDNS(domain string) (string, error) {
 	d.Set(TCPDNSLookup, "\""+domain+"\"")
-	r := strings.Split(string(d.Response(1000)), ":")
+	resp, err := d.Response(1000)
+	if err != nil {
+		return "", err
+	}
+	if !strings.Contains(string(resp), ":") {
+		return "", errors.New("GetDNS error:" + string(resp))
+	}
+	r := strings.Split(string(resp), ":")
 	if len(r) != 2 {
 		return "", errors.New("Invalid domain lookup result")
 	}
@@ -30,24 +37,30 @@ func (d *Device) GetDNS(domain string) (string, error) {
 func (d *Device) ConnectTCPSocket(addr, port string) error {
 	protocol := "TCP"
 	val := "\"" + protocol + "\",\"" + addr + "\"," + port + ",120"
-	d.Set(TCPConnect, val)
-	r := d.Response(1000)
-	if strings.Contains(string(r), "OK") {
-		return nil
+	err := d.Set(TCPConnect, val)
+	if err != nil {
+		return err
 	}
-	return errors.New("ConnectTCPSocket error:" + string(r))
+	_, e := d.Response(3000)
+	if e != nil {
+		return e
+	}
+	return nil
 }
 
 // ConnectUDPSocket creates a new UDP connection for the ESP8266/ESP32.
 func (d *Device) ConnectUDPSocket(addr, sendport, listenport string) error {
 	protocol := "UDP"
 	val := "\"" + protocol + "\",\"" + addr + "\"," + sendport + "," + listenport + ",2"
-	d.Set(TCPConnect, val)
-	r := d.Response(pause)
-	if strings.Contains(string(r), "OK") {
-		return nil
+	err := d.Set(TCPConnect, val)
+	if err != nil {
+		return err
 	}
-	return errors.New("ConnectUDPSocket error:" + string(r))
+	_, e := d.Response(3000)
+	if e != nil {
+		return e
+	}
+	return nil
 }
 
 // ConnectSSLSocket creates a new SSL socket connection for the ESP8266/ESP32.
@@ -57,17 +70,23 @@ func (d *Device) ConnectSSLSocket(addr, port string) error {
 	val := "\"" + protocol + "\",\"" + addr + "\"," + port + ",120"
 	d.Set(TCPConnect, val)
 	// this operation takes longer, so wait up to 6 seconds to complete.
-	r := d.Response(6000)
-	if strings.Contains(string(r), "CONNECT") {
-		return nil
+	_, err := d.Response(6000)
+	if err != nil {
+		return err
 	}
-	return errors.New("ConnectSSLSocket error:" + string(r))
+	return nil
 }
 
 // DisconnectSocket disconnects the ESP8266/ESP32 from the current TCP/UDP connection.
 func (d *Device) DisconnectSocket() error {
-	d.Execute(TCPClose)
-	d.Response(pause)
+	err := d.Execute(TCPClose)
+	if err != nil {
+		return err
+	}
+	_, e := d.Response(pause)
+	if e != nil {
+		return e
+	}
 	return nil
 }
 
@@ -76,14 +95,14 @@ func (d *Device) DisconnectSocket() error {
 func (d *Device) SetMux(mode int) error {
 	val := strconv.Itoa(mode)
 	d.Set(TCPMultiple, val)
-	d.Response(pause)
-	return nil
+	_, err := d.Response(pause)
+	return err
 }
 
 // GetMux returns the ESP8266/ESP32 current client TCP/UDP configuration for concurrent connections.
 func (d *Device) GetMux() ([]byte, error) {
 	d.Query(TCPMultiple)
-	return d.Response(pause), nil
+	return d.Response(pause)
 }
 
 // SetTCPTransferMode sets the ESP8266/ESP32 current client TCP/UDP transfer mode.
@@ -91,12 +110,12 @@ func (d *Device) GetMux() ([]byte, error) {
 func (d *Device) SetTCPTransferMode(mode int) error {
 	val := strconv.Itoa(mode)
 	d.Set(TransmissionMode, val)
-	d.Response(pause)
-	return nil
+	_, err := d.Response(pause)
+	return err
 }
 
 // GetTCPTransferMode returns the ESP8266/ESP32 current client TCP/UDP transfer mode.
-func (d *Device) GetTCPTransferMode() []byte {
+func (d *Device) GetTCPTransferMode() ([]byte, error) {
 	d.Query(TransmissionMode)
 	return d.Response(pause)
 }
@@ -108,7 +127,10 @@ func (d *Device) StartSocketSend(size int) error {
 
 	// when ">" is received, it indicates
 	// ready to receive data
-	r := d.Response(pause)
+	r, err := d.Response(2000)
+	if err != nil {
+		return err
+	}
 	if strings.Contains(string(r), ">") {
 		return nil
 	}
@@ -120,6 +142,6 @@ func (d *Device) StartSocketSend(size int) error {
 func (d *Device) EndSocketSend() error {
 	d.Write([]byte("+++"))
 
-	d.Response(pause)
-	return nil
+	_, err := d.Response(pause)
+	return err
 }

espat/wifi.go

@@ -16,7 +16,7 @@ const (
 )
 
 // GetWifiMode returns the ESP8266/ESP32 wifi mode.
-func (d *Device) GetWifiMode() []byte {
+func (d *Device) GetWifiMode() ([]byte, error) {
 	d.Query(WifiMode)
 	return d.Response(100)
 }
@@ -25,14 +25,14 @@ func (d *Device) GetWifiMode() []byte {
 func (d *Device) SetWifiMode(mode int) error {
 	val := strconv.Itoa(mode)
 	d.Set(WifiMode, val)
-	d.Response(pause)
-	return nil
+	_, err := d.Response(pause)
+	return err
 }
 
 // Wifi Client
 
 // GetConnectedAP returns the ESP8266/ESP32 is currently connected to as a client.
-func (d *Device) GetConnectedAP() []byte {
+func (d *Device) GetConnectedAP() ([]byte, error) {
 	d.Query(ConnectAP)
 	return d.Response(100)
 }
@@ -42,37 +42,43 @@ func (d *Device) GetConnectedAP() []byte {
 func (d *Device) ConnectToAP(ssid, pwd string, ws int) error {
 	val := "\"" + ssid + "\",\"" + pwd + "\""
 	d.Set(ConnectAP, val)
-	d.Response(ws * 1000)
+
+	_, err := d.Response(ws * 1000)
+	if err != nil {
+		return err
+	}
 	return nil
 }
 
 // DisconnectFromAP disconnects the ESP8266/ESP32 from the current access point.
 func (d *Device) DisconnectFromAP() error {
 	d.Execute(Disconnect)
-	d.Response(1000)
-	return nil
+	_, err := d.Response(1000)
+	return err
 }
 
 // GetClientIP returns the ESP8266/ESP32 current client IP addess when connected to an Access Point.
-func (d *Device) GetClientIP() string {
+func (d *Device) GetClientIP() (string, error) {
 	d.Query(SetStationIP)
-	return string(d.Response(100))
+	r, err := d.Response(1000)
+	return string(r), err
 }
 
 // SetClientIP sets the ESP8266/ESP32 current client IP addess when connected to an Access Point.
-func (d *Device) SetClientIP(ipaddr string) []byte {
+func (d *Device) SetClientIP(ipaddr string) error {
 	val := "\"" + ipaddr + "\""
 	d.Set(ConnectAP, val)
-	d.Response(500)
-	return nil
+	_, err := d.Response(500)
+	return err
 }
 
 // Access Point
 
 // GetAPConfig returns the ESP8266/ESP32 current configuration when acting as an Access Point.
-func (d *Device) GetAPConfig() string {
+func (d *Device) GetAPConfig() (string, error) {
 	d.Query(SoftAPConfigCurrent)
-	return string(d.Response(100))
+	r, err := d.Response(100)
+	return string(r), err
 }
 
 // SetAPConfig sets the ESP8266/ESP32 current configuration when acting as an Access Point.
@@ -83,35 +89,38 @@ func (d *Device) SetAPConfig(ssid, pwd string, ch, security int) error {
 	ecnval := strconv.Itoa(security)
 	val := "\"" + ssid + "\",\"" + pwd + "\"," + chval + "," + ecnval
 	d.Set(SoftAPConfigCurrent, val)
-	d.Response(1000)
-	return nil
+	_, err := d.Response(1000)
+	return err
 }
 
 // GetAPClients returns the ESP8266/ESP32 current clients when acting as an Access Point.
-func (d *Device) GetAPClients() string {
+func (d *Device) GetAPClients() (string, error) {
 	d.Query(ListConnectedIP)
-	return string(d.Response(100))
+	r, err := d.Response(100)
+	return string(r), err
 }
 
 // GetAPIP returns the ESP8266/ESP32 current IP addess when configured as an Access Point.
-func (d *Device) GetAPIP() string {
+func (d *Device) GetAPIP() (string, error) {
 	d.Query(SetSoftAPIPCurrent)
-	return string(d.Response(100))
+	r, err := d.Response(100)
+	return string(r), err
 }
 
 // SetAPIP sets the ESP8266/ESP32 current IP addess when configured as an Access Point.
 func (d *Device) SetAPIP(ipaddr string) error {
 	val := "\"" + ipaddr + "\""
 	d.Set(SetSoftAPIPCurrent, val)
-	d.Response(500)
-	return nil
+	_, err := d.Response(500)
+	return err
 }
 
 // GetAPConfigFlash returns the ESP8266/ESP32 current configuration acting as an Access Point
 // from flash storage. These settings are those used after a reset.
-func (d *Device) GetAPConfigFlash() string {
+func (d *Device) GetAPConfigFlash() (string, error) {
 	d.Query(SoftAPConfigFlash)
-	return string(d.Response(100))
+	r, err := d.Response(100)
+	return string(r), err
 }
 
 // SetAPConfigFlash sets the ESP8266/ESP32 current configuration acting as an Access Point,
@@ -123,15 +132,16 @@ func (d *Device) SetAPConfigFlash(ssid, pwd string, ch, security int) error {
 	ecnval := strconv.Itoa(security)
 	val := "\"" + ssid + "\",\"" + pwd + "\"," + chval + "," + ecnval
 	d.Set(SoftAPConfigFlash, val)
-	d.Response(1000)
-	return nil
+	_, err := d.Response(1000)
+	return err
 }
 
 // GetAPIPFlash returns the ESP8266/ESP32 IP address as saved to flash storage.
 // This is the IP address that will be used after a reset.
-func (d *Device) GetAPIPFlash() string {
+func (d *Device) GetAPIPFlash() (string, error) {
 	d.Query(SetSoftAPIPFlash)
-	return string(d.Response(100))
+	r, err := d.Response(100)
+	return string(r), err
 }
 
 // SetAPIPFlash sets the ESP8266/ESP32 current IP addess when configured as an Access Point.
@@ -139,6 +149,6 @@ func (d *Device) GetAPIPFlash() string {
 func (d *Device) SetAPIPFlash(ipaddr string) error {
 	val := "\"" + ipaddr + "\""
 	d.Set(SetSoftAPIPFlash, val)
-	d.Response(500)
-	return nil
+	_, err := d.Response(500)
+	return err
 }

examples/espat/espconsole/main.go

@@ -26,7 +26,7 @@ const pass = "YOURPASS"
 // these are the default pins for the Arduino Nano33 IoT.
 // change these to connect to a different UART or pins for the ESP8266/ESP32
 var (
-	uart = machine.UART2
+	uart = machine.UART1
 	tx   = machine.PA22
 	rx   = machine.PA23
 
@@ -43,28 +43,20 @@ func main() {
 	adaptor.Configure()
 
 	// first check if connected
-	if adaptor.Connected() {
+	if connectToESP() {
+		println("Connected to wifi adaptor.")
 		adaptor.Echo(false)
-		console.Write([]byte("\r\n"))
-		console.Write([]byte("ESP-AT console enabled.\r\n"))
-		console.Write([]byte("Firmware version:\r\n"))
-		console.Write(adaptor.Version())
-		console.Write([]byte("\r\n"))
 
-		if actAsAP {
-			provideAP()
-		} else {
-			connectToAP()
-		}
-
-		console.Write([]byte("Type an AT command then press enter:\r\n"))
-		prompt()
+		connectToAP()
 	} else {
-		console.Write([]byte("\r\n"))
-		console.Write([]byte("Unable to connect to wifi adaptor.\r\n"))
+		println("")
+		failMessage("Unable to connect to wifi adaptor.")
 		return
 	}
 
+	println("Type an AT command then press enter:")
+	prompt()
+
 	input := make([]byte, 64)
 	i := 0
 	for {
@@ -82,7 +74,8 @@ func main() {
 				adaptor.Write(input[:i+2])
 
 				// display response
-				console.Write(adaptor.Response(100))
+				r, _ := adaptor.Response(500)
+				console.Write(r)
 
 				// prompt
 				prompt()
@@ -101,28 +94,50 @@ func main() {
 }
 
 func prompt() {
-	console.Write([]byte("ESPAT>"))
+	print("ESPAT>")
+}
+
+// connect to ESP8266/ESP32
+func connectToESP() bool {
+	for i := 0; i < 5; i++ {
+		println("Connecting to wifi adaptor...")
+		if adaptor.Connected() {
+			return true
+		}
+		time.Sleep(1 * time.Second)
+	}
+	return false
 }
 
 // connect to access point
 func connectToAP() {
-	console.Write([]byte("Connecting to wifi network...\r\n"))
+	println("Connecting to wifi network '" + ssid + "'")
+
 	adaptor.SetWifiMode(espat.WifiModeClient)
 	adaptor.ConnectToAP(ssid, pass, 10)
-	console.Write([]byte("Connected.\r\n"))
-	console.Write([]byte(adaptor.GetClientIP()))
-	console.Write([]byte("\r\n"))
+
+	println("Connected.")
+	ip, err := adaptor.GetClientIP()
+	if err != nil {
+		failMessage(err.Error())
+	}
+
+	println(ip)
 }
 
 // provide access point
 func provideAP() {
-	time.Sleep(500 * time.Millisecond)
-	console.Write([]byte("Starting wifi network as access point '"))
-	console.Write([]byte(ssid))
-	console.Write([]byte("'...\r\n"))
+	println("Starting wifi network as access point '" + ssid + "'...")
 	adaptor.SetWifiMode(espat.WifiModeAP)
 	adaptor.SetAPConfig(ssid, pass, 7, espat.WifiAPSecurityWPA2_PSK)
-	console.Write([]byte("Ready.\r\n"))
-	console.Write([]byte(adaptor.GetAPIP()))
-	console.Write([]byte("\r\n"))
+	println("Ready.")
+	ip, _ := adaptor.GetAPIP()
+	println(ip)
+}
+
+func failMessage(msg string) {
+	for {
+		println(msg)
+		time.Sleep(1 * time.Second)
+	}
 }

examples/espat/esphub/main.go

@@ -24,7 +24,7 @@ const pass = "YOURPASS"
 // these are the default pins for the Arduino Nano33 IoT.
 // change these to connect to a different UART or pins for the ESP8266/ESP32
 var (
-	uart = machine.UART2
+	uart = machine.UART1
 	tx   = machine.PA22
 	rx   = machine.PA23
 
@@ -43,17 +43,14 @@ func main() {
 	readyled.High()
 
 	// first check if connected
-	if adaptor.Connected() {
+	if connectToESP() {
 		println("Connected to wifi adaptor.")
 		adaptor.Echo(false)
 
-		if actAsAP {
-			provideAP()
-		} else {
-			connectToAP()
-		}
+		connectToAP()
 	} else {
-		println("Unable to connect to wifi adaptor.")
+		println("")
+		failMessage("Unable to connect to wifi adaptor.")
 		return
 	}
 
@@ -86,21 +83,47 @@ func main() {
 	println("Done.")
 }
 
+// connect to ESP8266/ESP32
+func connectToESP() bool {
+	for i := 0; i < 5; i++ {
+		println("Connecting to wifi adaptor...")
+		if adaptor.Connected() {
+			return true
+		}
+		time.Sleep(1 * time.Second)
+	}
+	return false
+}
+
 // connect to access point
 func connectToAP() {
-	println("Connecting to wifi network...")
+	println("Connecting to wifi network '" + ssid + "'")
+
 	adaptor.SetWifiMode(espat.WifiModeClient)
 	adaptor.ConnectToAP(ssid, pass, 10)
+
 	println("Connected.")
-	println(adaptor.GetClientIP())
+	ip, err := adaptor.GetClientIP()
+	if err != nil {
+		failMessage(err.Error())
+	}
+
+	println(ip)
 }
 
 // provide access point
 func provideAP() {
-	println("Starting wifi network as access point:")
-	println(ssid)
+	println("Starting wifi network as access point '" + ssid + "'...")
 	adaptor.SetWifiMode(espat.WifiModeAP)
 	adaptor.SetAPConfig(ssid, pass, 7, espat.WifiAPSecurityWPA2_PSK)
 	println("Ready.")
-	println(adaptor.GetAPIP())
+	ip, _ := adaptor.GetAPIP()
+	println(ip)
+}
+
+func failMessage(msg string) {
+	for {
+		println(msg)
+		time.Sleep(1 * time.Second)
+	}
 }

examples/espat/espstation/main.go

@@ -24,7 +24,7 @@ const hubIP = "0.0.0.0"
 // these are the default pins for the Arduino Nano33 IoT.
 // change these to connect to a different UART or pins for the ESP8266/ESP32
 var (
-	uart = machine.UART2
+	uart = machine.UART1
 	tx   = machine.PA22
 	rx   = machine.PA23
 
@@ -39,13 +39,14 @@ func main() {
 	adaptor.Configure()
 
 	// first check if connected
-	if adaptor.Connected() {
+	if connectToESP() {
 		println("Connected to wifi adaptor.")
 		adaptor.Echo(false)
 
 		connectToAP()
 	} else {
-		println("Unable to connect to wifi adaptor.")
+		println("")
+		failMessage("Unable to connect to wifi adaptor.")
 		return
 	}
 
@@ -71,11 +72,37 @@ func main() {
 	println("Done.")
 }
 
+// connect to ESP8266/ESP32
+func connectToESP() bool {
+	for i := 0; i < 5; i++ {
+		println("Connecting to wifi adaptor...")
+		if adaptor.Connected() {
+			return true
+		}
+		time.Sleep(1 * time.Second)
+	}
+	return false
+}
+
 // connect to access point
 func connectToAP() {
-	println("Connecting to wifi network...")
+	println("Connecting to wifi network '" + ssid + "'")
+
 	adaptor.SetWifiMode(espat.WifiModeClient)
 	adaptor.ConnectToAP(ssid, pass, 10)
+
 	println("Connected.")
-	println(adaptor.GetClientIP())
+	ip, err := adaptor.GetClientIP()
+	if err != nil {
+		failMessage(err.Error())
+	}
+
+	println(ip)
+}
+
+func failMessage(msg string) {
+	for {
+		println(msg)
+		time.Sleep(1 * time.Second)
+	}
 }

examples/espat/mqttclient/main.go

@@ -25,8 +25,9 @@ const ssid = "YOURSSID"
 const pass = "YOURPASS"
 
 // IP address of the MQTT broker to use. Replace with your own info.
-//const server = "tcp://test.mosquitto.org:1883"
-const server = "ssl://test.mosquitto.org:8883"
+const server = "tcp://test.mosquitto.org:1883"
+
+//const server = "ssl://test.mosquitto.org:8883"
 
 // these are the default pins for the Arduino Nano33 IoT.
 // change these to connect to a different UART or pins for the ESP8266/ESP32
@@ -66,7 +67,7 @@ func main() {
 	opts := mqtt.NewClientOptions(adaptor)
 	opts.AddBroker(server).SetClientID("tinygo-client-" + randomString(10))
 
-	println("Connectng to MQTT...")
+	println("Connecting to MQTT broker at", server)
 	cl := mqtt.NewClient(opts)
 	if token := cl.Connect(); token.Wait() && token.Error() != nil {
 		failMessage(token.Error().Error())
@@ -105,13 +106,18 @@ func connectToESP() bool {
 
 // connect to access point
 func connectToAP() {
-	println("Connecting to wifi network...")
+	println("Connecting to wifi network '" + ssid + "'")
 
 	adaptor.SetWifiMode(espat.WifiModeClient)
 	adaptor.ConnectToAP(ssid, pass, 10)
 
 	println("Connected.")
-	println(adaptor.GetClientIP())
+	ip, err := adaptor.GetClientIP()
+	if err != nil {
+		failMessage(err.Error())
+	}
+
+	println(ip)
 }
 
 // Returns an int >= min, < max

examples/espat/mqttsub/main.go

@@ -0,0 +1,163 @@
+// This is a sensor station that uses a ESP8266 or ESP32 running on the device UART1.
+// It creates an MQTT connection that publishes a message every second
+// to an MQTT broker.
+//
+// In other words:
+// Your computer <--> UART0 <--> MCU <--> UART1 <--> ESP8266 <--> Internet <--> MQTT broker.
+//
+// You must also install the Paho MQTT package to build this program:
+//
+// 		go get -u github.com/eclipse/paho.mqtt.golang
+//
+package main
+
+import (
+	"fmt"
+	"machine"
+	"math/rand"
+	"time"
+
+	"tinygo.org/x/drivers/espat"
+	"tinygo.org/x/drivers/espat/mqtt"
+)
+
+// access point info
+const ssid = "YOURSSID"
+const pass = "YOURPASS"
+
+// IP address of the MQTT broker to use. Replace with your own info.
+//const server = "tcp://test.mosquitto.org:1883"
+
+const server = "ssl://test.mosquitto.org:8883"
+
+// change these to connect to a different UART or pins for the ESP8266/ESP32
+var (
+	// these are defaults for the Arduino Nano33 IoT.
+	uart = machine.UART1
+	tx   = machine.PA22
+	rx   = machine.PA23
+
+	console = machine.UART0
+
+	adaptor *espat.Device
+	cl      mqtt.Client
+	topicTx = "tinygo/tx"
+	topicRx = "tinygo/rx"
+)
+
+func subHandler(client mqtt.Client, msg mqtt.Message) {
+	fmt.Printf("[%s]  ", msg.Topic())
+	fmt.Printf("%s\r\n", msg.Payload())
+}
+
+func main() {
+	time.Sleep(3000 * time.Millisecond)
+
+	uart.Configure(machine.UARTConfig{TX: tx, RX: rx})
+	rand.Seed(time.Now().UnixNano())
+
+	// Init esp8266/esp32
+	adaptor = espat.New(uart)
+	adaptor.Configure()
+
+	// first check if connected
+	if connectToESP() {
+		println("Connected to wifi adaptor.")
+		adaptor.Echo(false)
+
+		connectToAP()
+	} else {
+		println("")
+		failMessage("Unable to connect to wifi adaptor.")
+		return
+	}
+
+	opts := mqtt.NewClientOptions(adaptor)
+	opts.AddBroker(server).SetClientID("tinygo-client-" + randomString(10))
+
+	println("Connecting to MQTT broker at", server)
+	cl = mqtt.NewClient(opts)
+	if token := cl.Connect(); token.Wait() && token.Error() != nil {
+		failMessage(token.Error().Error())
+	}
+
+	// subscribe
+	token := cl.Subscribe(topicRx, 0, subHandler)
+	token.Wait()
+	if token.Error() != nil {
+		failMessage(token.Error().Error())
+	}
+
+	go publishing()
+
+	select {}
+
+	// Right now this code is never reached. Need a way to trigger it...
+	println("Disconnecting MQTT...")
+	cl.Disconnect(100)
+
+	println("Done.")
+}
+
+func publishing() {
+	for {
+		println("Publishing MQTT message...")
+		data := []byte("{\"e\":[{ \"n\":\"hello\", \"v\":101 }]}")
+		token := cl.Publish(topicTx, 0, false, data)
+		token.Wait()
+		if token.Error() != nil {
+			println(token.Error().Error())
+		}
+
+		time.Sleep(1000 * time.Millisecond)
+	}
+}
+
+// connect to ESP8266/ESP32
+func connectToESP() bool {
+	for i := 0; i < 5; i++ {
+		println("Connecting to wifi adaptor...")
+		if adaptor.Connected() {
+			return true
+		}
+		time.Sleep(1 * time.Second)
+	}
+	return false
+}
+
+// connect to access point
+func connectToAP() {
+	println("Connecting to wifi network '" + ssid + "'")
+
+	adaptor.SetWifiMode(espat.WifiModeClient)
+	adaptor.ConnectToAP(ssid, pass, 10)
+
+	println("Connected.")
+	ip, err := adaptor.GetClientIP()
+	if err != nil {
+		failMessage(err.Error())
+	}
+
+	println(ip)
+}
+
+// Returns an int >= min, < max
+func randomInt(min, max int) int {
+	return min + rand.Intn(max-min)
+}
+
+// Generate a random string of A-Z chars with len = l
+func randomString(len int) string {
+	bytes := make([]byte, len)
+	for i := 0; i < len; i++ {
+		bytes[i] = byte(randomInt(65, 90))
+	}
+	return string(bytes)
+}
+
+func failMessage(msg string) {
+	for {
+		println(msg)
+		time.Sleep(1 * time.Second)
+	}
+}

examples/espat/tcpclient/main.go

@@ -24,7 +24,7 @@ const serverIP = "0.0.0.0"
 // these are the default pins for the Arduino Nano33 IoT.
 // change these to connect to a different UART or pins for the ESP8266/ESP32
 var (
-	uart = machine.UART2
+	uart = machine.UART1
 	tx   = machine.PA22
 	rx   = machine.PA23
 
@@ -39,13 +39,14 @@ func main() {
 	adaptor.Configure()
 
 	// first check if connected
-	if adaptor.Connected() {
+	if connectToESP() {
 		println("Connected to wifi adaptor.")
 		adaptor.Echo(false)
 
 		connectToAP()
 	} else {
-		println("Unable to connect to wifi adaptor.")
+		println("")
+		failMessage("Unable to connect to wifi adaptor.")
 		return
 	}
 
@@ -55,7 +56,10 @@ func main() {
 	laddr := &net.TCPAddr{Port: 8080}
 
 	println("Dialing TCP connection...")
-	conn, _ := net.DialTCP("tcp", laddr, raddr)
+	conn, err := net.DialTCP("tcp", laddr, raddr)
+	if err != nil {
+		failMessage(err.Error())
+	}
 
 	for {
 		// send data
@@ -71,11 +75,37 @@ func main() {
 	println("Done.")
 }
 
+// connect to ESP8266/ESP32
+func connectToESP() bool {
+	for i := 0; i < 5; i++ {
+		println("Connecting to wifi adaptor...")
+		if adaptor.Connected() {
+			return true
+		}
+		time.Sleep(1 * time.Second)
+	}
+	return false
+}
+
 // connect to access point
 func connectToAP() {
-	println("Connecting to wifi network...")
+	println("Connecting to wifi network '" + ssid + "'")
+
 	adaptor.SetWifiMode(espat.WifiModeClient)
 	adaptor.ConnectToAP(ssid, pass, 10)
+
 	println("Connected.")
-	println(adaptor.GetClientIP())
+	ip, err := adaptor.GetClientIP()
+	if err != nil {
+		failMessage(err.Error())
+	}
+
+	println(ip)
+}
+
+func failMessage(msg string) {
+	for {
+		println(msg)
+		time.Sleep(1 * time.Second)
+	}
 }

examples/mcp3008/main.go

@@ -0,0 +1,32 @@
+// Connects to a MCP3008 ADC via SPI.
+package main
+
+import (
+	"machine"
+	"time"
+
+	"tinygo.org/x/drivers/mcp3008"
+)
+
+var (
+	spi   = machine.SPI0
+	csPin = machine.D12
+)
+
+func main() {
+	spi.Configure(machine.SPIConfig{
+		Frequency: 4000000,
+		Mode:      3})
+
+	adc := mcp3008.New(spi, csPin)
+	adc.Configure()
+
+	// get "CH0" aka "machine.ADC" interface to channel 0 from ADC.
+	p := adc.CH0
+
+	for {
+		val := p.Get()
+		println(val)
+		time.Sleep(50 * time.Millisecond)
+	}
+}

mcp3008/mcp3008.go

@@ -0,0 +1,92 @@
+// Package mcp3008 implements a driver for the MCP3008 Analog to Digital Converter.
+//
+// Datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/21295d.pdf
+//
+package mcp3008 // import "tinygo.org/x/drivers/mcp3008"
+
+import (
+	"errors"
+	"machine"
+)
+
+// Device wraps MCP3008 SPI ADC.
+type Device struct {
+	bus machine.SPI
+	cs  machine.Pin
+	tx  []byte
+	rx  []byte
+	CH0 ADCPin
+	CH1 ADCPin
+	CH2 ADCPin
+	CH3 ADCPin
+	CH4 ADCPin
+	CH5 ADCPin
+	CH6 ADCPin
+	CH7 ADCPin
+}
+
+// ADCPin is the implementation of the ADConverter interface.
+type ADCPin struct {
+	machine.Pin
+	d *Device
+}
+
+// New returns a new MCP3008 driver. Pass in a fully configured SPI bus.
+func New(b machine.SPI, csPin machine.Pin) *Device {
+	d := &Device{bus: b,
+		cs: csPin,
+		tx: make([]byte, 3),
+		rx: make([]byte, 3),
+	}
+
+	// setup all channels
+	d.CH0 = d.GetADC(0)
+	d.CH1 = d.GetADC(1)
+	d.CH2 = d.GetADC(2)
+	d.CH3 = d.GetADC(3)
+	d.CH4 = d.GetADC(4)
+	d.CH5 = d.GetADC(5)
+	d.CH6 = d.GetADC(6)
+	d.CH7 = d.GetADC(7)
+
+	return d
+}
+
+// Configure sets up the device for communication
+func (d *Device) Configure() {
+	d.cs.Configure(machine.PinConfig{Mode: machine.PinOutput})
+}
+
+// Read analog data from channel
+func (d *Device) Read(ch int) (uint16, error) {
+	if ch < 0 || ch > 7 {
+		return 0, errors.New("invalid channel for MCP3008 Read")
+	}
+
+	return d.GetADC(ch).Get(), nil
+}
+
+// GetADC returns an ADC for a specific channel.
+func (d *Device) GetADC(ch int) ADCPin {
+	return ADCPin{machine.Pin(ch), d}
+}
+
+// Get the current reading for a specific ADCPin.
+func (p ADCPin) Get() uint16 {
+	p.d.tx[0] = 0x01
+	p.d.tx[1] = byte(8+p.Pin) << 4
+	p.d.tx[2] = 0x00
+
+	p.d.cs.Low()
+	p.d.bus.Tx(p.d.tx, p.d.rx)
+
+	// scale result to 16bit value like other ADCs
+	result := uint16((p.d.rx[1]&0x3))<<8 + uint16(p.d.rx[2])<<6
+	p.d.cs.High()
+
+	return result
+}
+
+// Configure here just for interface compatibility.
+func (p ADCPin) Configure() {
+}

semihosting/semihosting.go

@@ -0,0 +1,47 @@
+// Package semihosting implements parts of the ARM semihosting specification,
+// for communicating over a debug connection.
+//
+// If you want to use it in OpenOCD, you have to enable it first with the
+// following command:
+//
+//     arm semihosting enable
+package semihosting
+
+import (
+	"device/arm"
+	"unsafe"
+)
+
+// IOError is returned by I/O operations when they fail.
+type IOError struct {
+	BytesWritten int
+}
+
+func (e *IOError) Error() string {
+	return "semihosting: I/O error"
+}
+
+// Write writes the given data to the given file descriptor. It returns an
+// *IOError if the write was not successful.
+func Write(fd uintptr, data []byte) error {
+	if len(data) == 0 {
+		return nil
+	}
+	params := struct {
+		fd   uintptr
+		data unsafe.Pointer
+		len  int
+	}{
+		fd:   fd,
+		data: unsafe.Pointer(&data[0]),
+		len:  len(data),
+	}
+	unwritten := arm.SemihostingCall(arm.SemihostingWrite, uintptr(unsafe.Pointer(&params)))
+	if unwritten != 0 {
+		// Error: unwritten is the number of bytes not written.
+		return &IOError{
+			BytesWritten: len(data) - unwritten,
+		}
+	}
+	return nil
+}

semihosting/stdio.go

@@ -0,0 +1,20 @@
+package semihosting
+
+// These three file descriptors are connected to the host stdin/stdout/stderr,
+// and can be used for logging.
+var (
+	Stdin  = File{fd: 0}
+	Stdout = File{fd: 1}
+	Stderr = File{fd: 2}
+)
+
+// File represents a semihosting file descriptor.
+type File struct {
+	fd uintptr
+}
+
+// Write writes the given data buffer to the file descriptor, returning an error
+// if the write could not complete successfully.
+func (f *File) Write(buf []byte) error {
+	return Write(f.fd, buf)
+}

st7789/st7789.go

@@ -194,12 +194,13 @@ func (d *Device) FillRectangleWithBuffer(x, y, width, height int16, buffer []col
 	offset := int32(0)
 	for k > 0 {
 		for i := int32(0); i < d.batchLength; i++ {
-
-			c565 := RGBATo565(buffer[offset+i])
-			c1 := uint8(c565 >> 8)
-			c2 := uint8(c565)
-			data[i*2] = c1
-			data[i*2+1] = c2
+			if offset+i < int32(len(buffer)) {
+				c565 := RGBATo565(buffer[offset+i])
+				c1 := uint8(c565 >> 8)
+				c2 := uint8(c565)
+				data[i*2] = c1
+				data[i*2+1] = c2
+			}
 		}
 		if k >= d.batchLength {
 			d.Tx(data, false)

version.go

@@ -2,4 +2,4 @@ package drivers
 
 // Version returns a user-readable string showing the version of the drivers package for support purposes.
 // Update this value before release of new version of software.
-const Version = "0.7.0"
+const Version = "0.8.0"