Added networking stack (mostly copied from pico-weather) and added NTP sync

config.go.example

@@ -3,4 +3,6 @@ package main
 const (
 	WifiSSID = "MyWifiName"
 	WifiPass = "MyWifiPassword"
+
+	NtpServer = "216.239.35.0" // time.google.com IPv4
 )

go.mod

@@ -3,8 +3,15 @@ module git.metaunix.net/bitgoblin/pico-time
 go 1.25.2
 
 require (
+	github.com/soypat/cyw43439 v0.1.1
+	github.com/soypat/lneto v0.3.2
 	tinygo.org/x/drivers v0.36.0
 	tinygo.org/x/tinyfont v0.7.0
 )
 
-require github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510 // indirect
+require (
+	github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510 // indirect
+	github.com/soypat/seqs v0.0.0-20250124201400-0d65bc7c1710 // indirect
+	github.com/tinygo-org/pio v0.3.0 // indirect
+	golang.org/x/exp v0.0.0-20241204233417-43b7b7cde48d // indirect
+)

go.sum

@@ -1,5 +1,15 @@
 github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510 h1:El6M4kTTCOh6aBiKaUGG7oYTSPP8MxqL4YI3kZKwcP4=
 github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510/go.mod h1:pupxD2MaaD3pAXIBCelhxNneeOaAeabZDe5s4K6zSpQ=
+github.com/soypat/cyw43439 v0.1.1 h1:vcaTiVzfuz3keK7lJpVxStZ6tV8HCw7Ugzsh1k4mneE=
+github.com/soypat/cyw43439 v0.1.1/go.mod h1:R2uSILRwSPmcmmKy5Z0FtK4ypgiPf5YqK+F+IKmXqxc=
+github.com/soypat/lneto v0.3.2 h1:iUFeRSq2czT7Db6MMOsAnMCBlKCqvIr941zsNf9dcu0=
+github.com/soypat/lneto v0.3.2/go.mod h1:Be5PjwoYukvHFiUXxpYi8+ppH2F/gw/vjGBvFdv+Ti8=
+github.com/soypat/seqs v0.0.0-20250124201400-0d65bc7c1710 h1:Y9fBuiR/urFY/m76+SAZTxk2xAOS2n85f+H1CugajeA=
+github.com/soypat/seqs v0.0.0-20250124201400-0d65bc7c1710/go.mod h1:oCVCNGCHMKoBj97Zp9znLbQ1nHxpkmOY9X+UAGzOxc8=
+github.com/tinygo-org/pio v0.3.0 h1:opEnOtw58KGB4RJD3/n/Rd0/djYGX3DeJiXLI6y/yDI=
+github.com/tinygo-org/pio v0.3.0/go.mod h1:wf6c6lKZp+pQOzKKcpzchmRuhiMc27ABRuo7KVnaMFU=
+golang.org/x/exp v0.0.0-20241204233417-43b7b7cde48d h1:0olWaB5pg3+oychR51GUVCEsGkeCU/2JxjBgIo4f3M0=
+golang.org/x/exp v0.0.0-20241204233417-43b7b7cde48d/go.mod h1:qj5a5QZpwLU2NLQudwIN5koi3beDhSAlJwa67PuM98c=
 tinygo.org/x/drivers v0.36.0 h1:F0x342A6GWqh6abtCa57uAxCyz/b9MbGzvIVvIf+gpE=
 tinygo.org/x/drivers v0.36.0/go.mod h1:DQgKyHkB4G6IEOKVTAjApbKnWGwESN91EVJO+nMOE9Y=
 tinygo.org/x/tinyfont v0.7.0 h1:Ju901eGRThlHLoti9K7myMYyv4phd3I0DrJwc14NTTU=

main.go

@@ -4,28 +4,31 @@ import (
 	"fmt"
 	"image/color"
 	"machine"
+	"sync"
 	"time"
 
 	"tinygo.org/x/drivers/ssd1306"
 	"tinygo.org/x/tinyfont"
+	"tinygo.org/x/tinyfont/freemono"
 	"tinygo.org/x/tinyfont/proggy"
-  "tinygo.org/x/tinyfont/freemono"
 )
 
 var (
 	white = color.RGBA{R: 255, G: 255, B: 255, A: 255}
 	black = color.RGBA{R: 0, G: 0, B: 0, A: 255}
+
+	mu          sync.Mutex
+	currentTime time.Time
 )
 
 func main() {
-	// Configure I2C0 using GP4 (SDA) and GP5 (SCL) at 400kHz
+	// Configure I2C0 with your pins: GP16 (SDA) and GP17 (SCL)
 	machine.I2C0.Configure(machine.I2CConfig{
 		Frequency: 400 * machine.KHz,
-    SDA:       machine.GP16,
+		SDA:       machine.GP16,
-    SCL:       machine.GP17,
+		SCL:       machine.GP17,
 	})
 
-	// Initialize the display (default I2C address for SSD1306 is usually 0x3C)
 	display := ssd1306.NewI2C(machine.I2C0)
 	display.Configure(ssd1306.Config{
 		Address: 0x3C,
@@ -33,28 +36,65 @@ func main() {
 		Height:  64,
 	})
 
-	display.ClearDisplay()
+	// 1. Splash / Connection screen
+	display.ClearBuffer()
+	tinyfont.WriteLine(display, &proggy.TinySZ8pt7b, 8, 32, "Connecting Wi-Fi...", white)
+	display.Display()
 
-	// Base time for clock tracking (update to current time or set via NTP)
+	// 2. Initialize Wi-Fi hardware and lneto stack
-	currentTime := time.Date(2026, time.September, 7, 12, 0, 0, 0, time.UTC)
+  netStack, err := InitNetwork(WifiSSID, WifiPass)
+	if err != nil {
+		display.ClearBuffer()
+		tinyfont.WriteLine(display, &proggy.TinySZ8pt7b, 8, 32, "Wi-Fi Error!", white)
+		display.Display()
+		println("Wi-Fi init error:", err.Error())
+		for {}
+	}
+
+	// 3. NTP Fetch Status
+	display.ClearBuffer()
+	tinyfont.WriteLine(display, &proggy.TinySZ8pt7b, 8, 32, "Syncing NTP...", white)
+	display.Display()
+
+  syncedTime, err := netStack.FetchNTP(NtpServer)
+	if err != nil {
+		println("Initial NTP sync error:", err.Error())
+		currentTime = time.Date(2026, time.September, 7, 12, 0, 0, 0, time.UTC)
+	} else {
+		currentTime = syncedTime
+	}
+
+	// 4. Background NTP re-sync routine (every 1 hour)
+	go func() {
+		resyncTicker := time.NewTicker(1 * time.Hour)
+		for range resyncTicker.C {
+      if t, err := netStack.FetchNTP(NtpServer); err == nil {
+				mu.Lock()
+				currentTime = t
+				mu.Unlock()
+			}
+		}
+	}()
+
+	// 5. 1Hz UI rendering loop
 	ticker := time.NewTicker(1 * time.Second)
-
 	for range ticker.C {
+		mu.Lock()
 		currentTime = currentTime.Add(1 * time.Second)
+		now := currentTime
+		mu.Unlock()
 
-		// Format time and date strings
+		// Optional: Apply timezone offset if needed (e.g. now = now.Add(-4 * time.Hour))
-		timeStr := fmt.Sprintf("%02d:%02d:%02d", currentTime.Hour(), currentTime.Minute(), currentTime.Second())
+		timeStr := fmt.Sprintf("%02d:%02d:%02d", now.Hour(), now.Minute(), now.Second())
-		dateStr := currentTime.Format("Mon, Jan 02 2006")
+		dateStr := now.Format("Mon, Jan 02 2006")
 
-		// Clear screen buffer
 		display.ClearBuffer()
 
-		// Render text to display buffer:
+		// Top: Date with Proggy
-		// WriteLine(target, font, x, y, text, color)
 		tinyfont.WriteLine(display, &proggy.TinySZ8pt7b, 16, 14, dateStr, white)
+		// Center: Time with Freemono Bold 12pt
 		tinyfont.WriteLine(display, &freemono.Bold12pt7b, 6, 44, timeStr, white)
 
-		// Push frame buffer to the OLED panel
 		display.Display()
 	}
 }

network.go

@@ -0,0 +1,309 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net"
+	"net/netip"
+	"syscall"
+	"time"
+
+	"github.com/soypat/cyw43439"
+	"github.com/soypat/lneto"
+	"github.com/soypat/lneto/ethernet"
+	"github.com/soypat/lneto/x/xnet"
+)
+
+const (
+	pollTime     = 5 * time.Millisecond
+	protoTimeout = 5 * time.Second
+	protoRetries = 3
+
+	tcpBufsize            = 2048
+	tcpPacketQueueSize    = 4
+	tcpConnPoolSize       = 5
+	tcpEstablishedTimeout = 4 * time.Second
+	tcpCloseTimeout       = protoTimeout
+)
+
+var nanotime = func() int64 {
+	return time.Now().UnixNano()
+}
+
+// CywAdapter bridges the cyw43439 driver to the lneto interface requirements.
+type CywAdapter struct {
+	dev    *cyw43439.Device
+	rxBuf  [1514]byte
+	rxLen  int
+	hasPkt bool
+}
+
+func NewCywAdapter(dev *cyw43439.Device) *CywAdapter {
+	adapter := &CywAdapter{dev: dev}
+
+	dev.RecvEthHandle(func(pkt []byte) error {
+		if !adapter.hasPkt && len(pkt) <= len(adapter.rxBuf) {
+			copy(adapter.rxBuf[:], pkt)
+			adapter.rxLen = len(pkt)
+			adapter.hasPkt = true
+		}
+		return nil
+	})
+
+	return adapter
+}
+
+// In CywAdapter:
+func (a *CywAdapter) PollHardware() error {
+	_, err := a.dev.TryPoll()
+	return err
+}
+
+func (a *CywAdapter) SendEth(frame []byte) error {
+	return a.dev.SendEth(frame)
+}
+
+func (a *CywAdapter) RecvEth(dst []byte) (int, error) {
+	if !a.hasPkt {
+		return 0, nil
+	}
+	n := copy(dst, a.rxBuf[:a.rxLen])
+	a.hasPkt = false
+	a.rxLen = 0
+	return n, nil
+}
+
+func (a *CywAdapter) HardwareAddress6() ([6]byte, error) {
+	return a.dev.HardwareAddr6()
+}
+
+func (a *CywAdapter) MaxFrameLength() (int, error) {
+	return 1514, nil
+}
+
+type NetworkStack struct {
+	adapter *CywAdapter
+	stack   *xnet.StackAsync
+	gostack xnet.StackGo
+	localIP netip.Addr
+}
+
+func InitNetwork(ssid, pass string) (*NetworkStack, error) {
+	println("Initializing CYW43439 Wi-Fi hardware...")
+	dev := cyw43439.NewPicoWDevice()
+	cfg := cyw43439.DefaultWifiConfig()
+	if err := dev.Init(cfg); err != nil {
+		return nil, fmt.Errorf("device init failed: %w", err)
+	}
+
+	println("Associating with SSID:", ssid)
+	if err := dev.JoinWPA2(ssid, pass); err != nil {
+		return nil, fmt.Errorf("wifi association failed: %w", err)
+	}
+	println("Wi-Fi associated.")
+
+	adapter := NewCywAdapter(dev)
+	hwaddr, err := adapter.HardwareAddress6()
+	if err != nil {
+		return nil, fmt.Errorf("read MAC: %w", err)
+	}
+	framelen, err := adapter.MaxFrameLength()
+	if err != nil {
+		return nil, fmt.Errorf("max frame len: %w", err)
+	}
+
+	stack := &xnet.StackAsync{}
+	err = stack.Reset(xnet.StackConfig{
+		Hostname:          "pico2w-bme280",
+		RandSeed:          time.Now().UnixNano(),
+		MaxActiveTCPPorts: 2,
+		MTU:               uint16(framelen - ethernet.MaxOverheadSize),
+		HardwareAddress:   hwaddr,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("stack config reset: %w", err)
+	}
+
+	// Start background frame pump
+	ctx := context.Background()
+	go stackLoop(ctx, stack, adapter)
+
+	println("Acquiring IP via DHCP...")
+	rstack := stack.StackRetrying(stackBackoff)
+	results, err := rstack.DoDHCPv4([4]byte{}, protoTimeout, protoRetries)
+	if err != nil {
+		return nil, fmt.Errorf("DHCP failed: %w", err)
+	}
+
+	err = stack.AssimilateDHCPResults(results)
+	if err != nil {
+		return nil, fmt.Errorf("assimilate DHCP failed: %w", err)
+	}
+
+	println("Resolving router MAC...")
+	gateway, err := rstack.DoResolveHardwareAddress6(results.Router, protoTimeout, protoRetries)
+	if err != nil {
+		return nil, fmt.Errorf("resolving router MAC failed: %w", err)
+	}
+	stack.SetGatewayHardwareAddr(gateway)
+
+	localIP := netip.AddrFrom4(results.AssignedAddr4)
+	println("DHCP lease assigned! IP:", localIP.String())
+
+	gostack := stack.StackBlocking(stackBackoff).StackGo(xnet.StackGoConfig{
+		ListenerPoolConfig: xnet.TCPPoolConfig{
+			PoolSize:           tcpConnPoolSize,
+			QueueSize:          tcpPacketQueueSize,
+			TxBufSize:          tcpBufsize,
+			RxBufSize:          tcpBufsize,
+			NanoTime:           nanotime,
+			EstablishedTimeout: tcpEstablishedTimeout,
+			ClosingTimeout:     tcpCloseTimeout,
+			NewBackoff:         func() lneto.BackoffStrategy { return tcpBackoff },
+		},
+	})
+
+	return &NetworkStack{
+		adapter: adapter,
+		stack:   stack,
+		gostack: gostack,
+		localIP: localIP,
+	}, nil
+}
+
+func (ns *NetworkStack) DialTCP(ctx context.Context, hostIP string, port uint16) (net.Conn, error) {
+	rIP, err := netip.ParseAddr(hostIP)
+	if err != nil {
+		return nil, fmt.Errorf("invalid host IPv4: %w", err)
+	}
+
+	laddr := net.TCPAddrFromAddrPort(netip.AddrPortFrom(ns.localIP, 0))
+	raddr := net.TCPAddrFromAddrPort(netip.AddrPortFrom(rIP, port))
+
+	const sockstream = 0x1
+	c, err := ns.gostack.Socket(ctx, "tcp", syscall.AF_INET, sockstream, laddr, raddr)
+	if err != nil {
+		return nil, fmt.Errorf("socket dial: %w", err)
+	}
+
+	conn, ok := c.(net.Conn)
+	if !ok {
+		return nil, errors.New("socket did not return a stream connection")
+	}
+
+	return conn, nil
+}
+
+func stackLoop(ctx context.Context, stack *xnet.StackAsync, adapter *CywAdapter) {
+	frameLength, _ := adapter.MaxFrameLength()
+	buf := make([]byte, frameLength)
+
+	for ctx.Err() == nil {
+		// 1. Pump the CYW43439 hardware over SPI to trigger RecvEthHandle
+		_ = adapter.PollHardware()
+
+		// 2. Ingress: read from adapter into lneto
+		nread, err := adapter.RecvEth(buf[:])
+		if err != nil {
+			println("recv err:", err.Error())
+		} else if nread > 0 {
+			err = stack.IngressEthernet(buf[:nread])
+			if err != nil && err != lneto.ErrPacketDrop {
+				println("ingress err:", err.Error())
+			}
+		}
+
+		// 3. Egress: send out any frames generated by lneto
+		nwrite, err := stack.EgressEthernet(buf[:])
+		if err != nil {
+			println("egress err:", err.Error())
+		} else if nwrite > 0 {
+			if err := adapter.SendEth(buf[:nwrite]); err != nil {
+				println("send eth err:", err.Error())
+			}
+		}
+
+		if nwrite == 0 && nread == 0 {
+			time.Sleep(pollTime)
+		}
+	}
+}
+
+func stackBackoff(consecutiveBackoffs uint) time.Duration {
+	if consecutiveBackoffs < 10 {
+		return time.Millisecond
+	}
+	return 10 * time.Millisecond
+}
+
+func tcpBackoff(consecutiveBackoffs uint) time.Duration {
+	const (
+		minWait  = uint32(time.Microsecond)
+		maxWait  = 5 * uint32(time.Millisecond)
+		maxShift = 22
+	)
+	shifted := minWait << min(consecutiveBackoffs, maxShift)
+	wait := min(shifted, maxWait)
+	return time.Duration(wait)
+}
+
+// FetchNTP requests the current time from an NTP server IPv4 address over UDP (port 123).
+func (ns *NetworkStack) FetchNTP(serverIP string) (time.Time, error) {
+	ip, err := netip.ParseAddr(serverIP)
+	if err != nil || !ip.Is4() {
+		return time.Time{}, fmt.Errorf("invalid IPv4 address: %w", err)
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), protoTimeout)
+	defer cancel()
+
+	laddr := net.UDPAddrFromAddrPort(netip.AddrPortFrom(ns.localIP, 0))
+	raddr := net.UDPAddrFromAddrPort(netip.AddrPortFrom(ip, 123))
+
+	const sockDgram = 0x2
+	c, err := ns.gostack.Socket(ctx, "udp", syscall.AF_INET, sockDgram, laddr, raddr)
+	if err != nil {
+		return time.Time{}, fmt.Errorf("udp socket dial: %w", err)
+	}
+	conn, ok := c.(net.Conn)
+	if !ok {
+		return time.Time{}, errors.New("socket did not return a net.Conn")
+	}
+	defer conn.Close()
+
+	_ = conn.SetDeadline(time.Now().Add(protoTimeout))
+
+	// Standard NTP request packet (48 bytes, leap indicator 0, version 4, mode 3 client = 0x23)
+	req := make([]byte, 48)
+	req[0] = 0x23
+
+	if _, err := conn.Write(req); err != nil {
+		return time.Time{}, fmt.Errorf("ntp write error: %w", err)
+	}
+
+	resp := make([]byte, 48)
+	n, err := conn.Read(resp)
+	if err != nil {
+		return time.Time{}, fmt.Errorf("ntp read error: %w", err)
+	}
+	if n < 48 {
+		return time.Time{}, fmt.Errorf("ntp response too short: %d bytes", n)
+	}
+
+	// Transmit timestamp seconds are at bytes 40-43 (big-endian)
+	secs := uint32(resp[40])<<24 | uint32(resp[41])<<16 | uint32(resp[42])<<8 | uint32(resp[43])
+	fraction := uint32(resp[44])<<24 | uint32(resp[45])<<16 | uint32(resp[46])<<8 | uint32(resp[47])
+
+	// NTP epoch begins Jan 1, 1900. Unix epoch begins Jan 1, 1970.
+	// Difference is 2,208,988,800 seconds (70 years).
+	const ntpEpochOffset = 2208988800
+	if secs < ntpEpochOffset {
+		return time.Time{}, errors.New("invalid NTP timestamp received")
+	}
+
+	unixSecs := int64(secs - ntpEpochOffset)
+	nanos := (int64(fraction) * 1e9) >> 32
+
+	return time.Unix(unixSecs, nanos), nil
+}