update with latest drivers changes

esp32s3-lockup/go.mod

@@ -1,3 +0,0 @@
-module esp32s3lockup
-
-go 1.26.2

esp32s3-lockup/main.go

@@ -1,35 +0,0 @@
-package main
-
-import (
-	"machine"
-	"time"
-)
-
-func main() {
-	time.Sleep(3 * time.Second)
-
-	led := machine.GPIO37
-	led.Configure(machine.PinConfig{Mode: machine.PinOutput})
-
-	txDone := true
-	count := 0
-
-	processingCount := 0
-	for {
-		if txDone {
-			txDone = false
-			led.Set(false)
-			time.Sleep(249 * time.Millisecond)
-			led.Set(true)
-			println("hello world", count)
-			count += 1
-		} else {
-			if processingCount > 100000000 {
-				txDone = true
-				println("stall done")
-				processingCount = 0
-			}
-			processingCount += 1
-		}
-	}
-}

lilygo-t3s3-sx1280-lora2udp/go.mod

@@ -0,0 +1,17 @@
+module lilygot3s3
+
+go 1.26.2
+
+require (
+	tinygo.org/x/drivers v0.35.0
+	tinygo.org/x/espradio v0.1.0
+)
+
+require (
+	github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510 // indirect
+	github.com/soypat/lneto v0.1.1-0.20260425023453-aa77403a2b32 // indirect
+)
+
+replace tinygo.org/x/drivers => /Users/jwetzell/Projects/drivers
+
+replace tinygo.org/x/espradio => /Users/jwetzell/Projects/espradio

lilygo-t3s3-sx1280-lora2udp/go.sum

@@ -0,0 +1,4 @@
+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/lneto v0.1.1-0.20260425023453-aa77403a2b32 h1:4fNa4mcNPVTMJ3Kzn+cS/LqmpXhKM9SiZ9Vgu/Ucq3c=
+github.com/soypat/lneto v0.1.1-0.20260425023453-aa77403a2b32/go.mod h1:Be5PjwoYukvHFiUXxpYi8+ppH2F/gw/vjGBvFdv+Ti8=

lilygo-t3s3-sx1280-lora2udp/main.go

@@ -0,0 +1,254 @@
+package main
+
+import (
+	"machine"
+	"net"
+	"runtime"
+	"sync/atomic"
+	"time"
+
+	"tinygo.org/x/drivers/lora"
+	"tinygo.org/x/drivers/netdev"
+	nl "tinygo.org/x/drivers/netlink"
+	"tinygo.org/x/drivers/sx128x"
+	link "tinygo.org/x/espradio/netlink"
+)
+
+var (
+	ssid     string
+	password string
+)
+
+type LoRaConfig struct {
+	Frequency       uint32
+	Power           int8
+	RadioRamp       sx128x.RadioRampTime
+	RegulatorMode   sx128x.RegulatorMode
+	SpreadingFactor sx128x.LoRaSpreadingFactor
+	Bandwidth       sx128x.LoRaBandwidth
+	CodingRate      sx128x.LoRaCodingRate
+	PreambleLength  uint32
+	HeaderType      sx128x.LoRaHeaderType
+	CrcType         sx128x.LoRaCrcType
+	IqType          sx128x.LoRaIqType
+	SyncWord        uint16
+}
+
+func main() {
+	time.Sleep(3 * time.Second)
+
+	link := link.Esplink{}
+	netdev.UseNetdev(&link)
+
+	println("Connecting to WiFi...")
+	err := link.NetConnect(&nl.ConnectParams{
+		Ssid:       ssid,
+		Passphrase: password,
+	})
+	if err != nil {
+		panic("connect failed: " + err.Error())
+	}
+
+	conn, err := net.Dial("udp", "10.0.0.50:53000")
+	if err != nil {
+		panic("dial failed: " + err.Error())
+	}
+	defer conn.Close()
+
+	println("Connected to WiFi.")
+
+	led := machine.GPIO37
+	led.Configure(machine.PinConfig{Mode: machine.PinOutput})
+
+	spi := machine.SPI0
+	spi.Configure(machine.SPIConfig{
+		Mode:      0,
+		Frequency: 8 * 1e6,
+		SDO:       machine.GPIO6,
+		SDI:       machine.GPIO3,
+		SCK:       machine.GPIO5,
+	})
+
+	nssPin := machine.GPIO7
+	nssPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	nssPin.Set(true)
+
+	resetPin := machine.GPIO8
+	resetPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	resetPin.Set(true)
+
+	busyPin := machine.GPIO36
+	busyPin.Configure(machine.PinConfig{Mode: machine.PinInput})
+
+	println("initializing radio...")
+
+	radio := sx128x.New(
+		spi,
+		nssPin,
+		resetPin,
+		busyPin,
+	)
+
+	dio1Pin := machine.GPIO9
+	dio1Pin.Configure(machine.PinConfig{Mode: machine.PinInput})
+
+	txDone := atomic.Bool{}
+	txDone.Store(true)
+	rxDone := atomic.Bool{}
+	rxDone.Store(true)
+	timeout := atomic.Bool{}
+	timeout.Store(true)
+
+	dio1Interrupt := atomic.Bool{}
+	dio1Interrupt.Store(false)
+
+	dio1Pin.SetInterrupt(machine.PinRising, func(machine.Pin) {
+		dio1Interrupt.Store(true)
+	})
+
+	loraConfig := LoRaConfig{
+		Frequency:     2400000000,              // 2.4Ghz
+		Power:         13,                      // dBm
+		RadioRamp:     sx128x.RADIO_RAMP_02_US, // 2 microsecond ramp time
+		RegulatorMode: sx128x.REGULATOR_DC_DC,
+
+		SpreadingFactor: sx128x.LORA_SF_9,
+		Bandwidth:       sx128x.LORA_BW_1600,
+		CodingRate:      sx128x.LORA_CR_4_7,
+		PreambleLength:  12,
+		HeaderType:      sx128x.LORA_HEADER_EXPLICIT,
+		CrcType:         sx128x.LORA_CRC_DISABLE,
+		IqType:          sx128x.LORA_IQ_STD,
+		SyncWord:        0x1424, // the default private sync word
+	}
+
+	radio.WaitWhileBusy(time.Second)
+	SetupLora(radio, loraConfig)
+	println("radio initialized, waiting for messages...")
+
+	for {
+		runtime.Gosched()
+
+		if dio1Interrupt.Load() {
+			// println("DIO1 interrupt triggered")
+			irqStatus, _ := radio.GetIrqStatus()
+			println("irq status:", irqStatus)
+
+			if irqStatus&sx128x.IRQ_TX_DONE_MASK != 0 {
+				txDone.Store(true)
+				timeout.Store(false)
+				led.Set(false)
+			}
+			if irqStatus&sx128x.IRQ_RX_DONE_MASK != 0 {
+				rxDone.Store(true)
+				timeout.Store(false)
+				led.Set(true)
+				println("rx done")
+			}
+			if irqStatus&sx128x.IRQ_RX_TX_TIMEOUT_MASK != 0 {
+				timeout.Store(true)
+				txDone.Store(true)
+				rxDone.Store(true)
+				println("rx/tx timeout")
+			}
+			dio1Interrupt.Store(false)
+		}
+
+		if rxDone.Load() {
+			rxDone.Store(false)
+			if !timeout.Load() {
+				rxLength, rxPointer, _ := radio.GetRxBufferStatus()
+				rxData, _ := radio.ReadBuffer(rxPointer, rxLength)
+				// num, err := conn.Write(rxData)
+				// if err != nil {
+				// 	println("failed to send OSC message:", err)
+				// } else {
+				// 	println("sent", num, "bytes to broker")
+				// }
+				println("received message:", string(rxData))
+
+				led.Set(false)
+			}
+			Rx(radio, loraConfig)
+			println("radio set to receive")
+		} else {
+			if dio1Pin.Get() {
+				irqStatus, _ := radio.GetIrqStatus()
+
+				if irqStatus&sx128x.IRQ_TX_DONE_MASK != 0 {
+					txDone.Store(true)
+					timeout.Store(false)
+					led.Set(false)
+				}
+				if irqStatus&sx128x.IRQ_RX_DONE_MASK != 0 {
+					rxDone.Store(true)
+					timeout.Store(false)
+					led.Set(true)
+				}
+				if irqStatus&sx128x.IRQ_RX_TX_TIMEOUT_MASK != 0 {
+					timeout.Store(true)
+					txDone.Store(true)
+					rxDone.Store(true)
+				}
+			}
+		}
+	}
+}
+
+func SetupLora(radio *sx128x.Device, config LoRaConfig) {
+	// Switch to standby prior to configuration changes
+
+	circuitMode, _, _ := radio.GetStatus()
+	if circuitMode != sx128x.CIRCUIT_MODE_STDBY_RC {
+		radio.SetStandby(sx128x.STANDBY_RC)
+	}
+	// Clear errors, disable radio interrupts for the moment
+	radio.SetPacketType(sx128x.PACKET_TYPE_LORA)
+	radio.SetCadParams(uint8(sx128x.LORA_CAD_08_SYMBOLS))
+	radio.SetRegulatorMode(sx128x.REGULATOR_DC_DC)
+
+	radio.SetRfFrequency(config.Frequency)
+	radio.SetModulationParamsLoRa(config.SpreadingFactor, config.Bandwidth, config.CodingRate)
+
+	data := [1]uint8{}
+	if config.SpreadingFactor == lora.SpreadingFactor5 || config.SpreadingFactor == lora.SpreadingFactor6 {
+		data[0] = 0x1E
+	} else if config.SpreadingFactor == lora.SpreadingFactor7 || config.SpreadingFactor == lora.SpreadingFactor8 {
+		data[0] = 0x37
+	} else {
+		data[0] = 0x32
+	}
+	radio.WriteRegister(0x925, data[:])
+	existing, _ := radio.ReadRegister(0x93C)
+	data[0] = existing | 0x01
+	radio.WriteRegister(0x93C, data[:])
+
+	radio.SetTxParams(config.Power, sx128x.RADIO_RAMP_02_US)
+	radio.SetPacketParamsLoRa(config.PreambleLength, config.HeaderType, 0xFF, config.CrcType, config.IqType)
+	var syncWord [2]uint8
+	syncWord[0] = uint8(config.SyncWord >> 8)
+	syncWord[1] = uint8(config.SyncWord & 0x00FF)
+
+	radio.WriteRegister(sx128x.REG_LORA_SYNC_WORD_MSB, syncWord[:])
+}
+
+func checkStatus(radio *sx128x.Device, operation string) {
+	circuitMode, commandStatus, _ := radio.GetStatus()
+	if commandStatus != sx128x.COMMAND_STATUS_SUCCESS {
+		println(operation, "-> failed with status:", commandStatus)
+	}
+	if circuitMode != sx128x.CIRCUIT_MODE_STDBY_RC {
+		println(operation, "-> entered circuit mode:", circuitMode)
+	}
+}
+
+func Rx(radio *sx128x.Device, loraConfig LoRaConfig) {
+	radio.SetStandby(sx128x.STANDBY_XOSC)
+	radio.SetBufferBaseAddress(0, 0)
+	radio.SetDioIrqParams(sx128x.IRQ_RX_DONE_MASK|sx128x.IRQ_RX_TX_TIMEOUT_MASK, sx128x.IRQ_RX_DONE_MASK|sx128x.IRQ_RX_TX_TIMEOUT_MASK, 0x00, 0x00)
+	radio.ClearIrqStatus(sx128x.IRQ_ALL_MASK)
+	err := radio.SetRx(sx128x.PERIOD_BASE_4_MS, 250)
+	if err != nil {
+		println("failed to set RX mode:", err)
+	}
+}

lilygo-t3s3-sx128x/main.go

@@ -7,10 +7,24 @@ import (
 	"time"
 
 	"github.com/jwetzell/osc-go"
-	"tinygo.org/x/drivers/lora"
 	"tinygo.org/x/drivers/sx128x"
 )
 
+type LoRaConfig struct {
+	Frequency       uint32
+	Power           int8
+	RadioRamp       sx128x.RadioRampTime
+	RegulatorMode   sx128x.RegulatorMode
+	SpreadingFactor sx128x.LoRaSpreadingFactor
+	Bandwidth       sx128x.LoRaBandwidth
+	CodingRate      sx128x.LoRaCodingRate
+	PreambleLength  uint32
+	HeaderType      sx128x.LoRaHeaderType
+	CrcType         sx128x.LoRaCrcType
+	IqType          sx128x.LoRaIqType
+	SyncWord        uint16
+}
+
 func main() {
 	time.Sleep(3 * time.Second)
 
@@ -65,13 +79,46 @@ func main() {
 	timeout := atomic.Bool{}
 	timeout.Store(true)
 
+	dio1Interrupt := atomic.Bool{}
+	dio1Interrupt.Store(false)
+
 	dio1Pin.SetInterrupt(machine.PinRising, func(machine.Pin) {
-		irqStatus := radio.GetIrqStatus()
+		dio1Interrupt.Store(true)
+	})
+
+	loraConfig := LoRaConfig{
+		Frequency:     2400000000,              // 2.4Ghz
+		Power:         13,                      // dBm
+		RadioRamp:     sx128x.RADIO_RAMP_02_US, // 2 microsecond ramp time
+		RegulatorMode: sx128x.REGULATOR_DC_DC,
+
+		SpreadingFactor: sx128x.LORA_SF_9,
+		Bandwidth:       sx128x.LORA_BW_1600,
+		CodingRate:      sx128x.LORA_CR_4_7,
+		PreambleLength:  12,
+		HeaderType:      sx128x.LORA_HEADER_EXPLICIT,
+		CrcType:         sx128x.LORA_CRC_DISABLE,
+		IqType:          sx128x.LORA_IQ_STD,
+		SyncWord:        0x1424, // the default private sync word
+	}
+
+	radio.WaitWhileBusy(time.Second)
+	SetupLora(radio, loraConfig)
+
+	oscMessage := osc.OSCMessage{
+		Address: "/cue/1/go",
+		Args:    []osc.OSCArg{},
+	}
+
+	for {
+		if dio1Interrupt.Load() {
+			irqStatus, _ := radio.GetIrqStatus()
 
 			if irqStatus&sx128x.IRQ_TX_DONE_MASK != 0 {
 				txDone.Store(true)
 				timeout.Store(false)
 				led.Set(false)
+				println("tx done")
 			}
 			if irqStatus&sx128x.IRQ_RX_DONE_MASK != 0 {
 				rxDone.Store(true)
@@ -83,36 +130,8 @@ func main() {
 				txDone.Store(true)
 				rxDone.Store(true)
 			}
-	})
+			dio1Interrupt.Store(false)
-
-	loraConfig := lora.Config{
-		Freq:           2400000000,
-		Bw:             lora.Bandwidth_1625_0,
-		Sf:             lora.SpreadingFactor9,
-		Cr:             lora.CodingRate4_7,
-		HeaderType:     sx128x.LORA_EXPLICIT_HEADER,
-		Preamble:       12,
-		Ldr:            lora.LowDataRateOptimizeOff,
-		Iq:             sx128x.LORA_IQ_STD,
-		Crc:            sx128x.LORA_CRC_DISABLE,
-		SyncWord:       0x1424,
-		LoraTxPowerDBm: 13,
 		}
-
-	radio.WaitWhileBusy()
-	SetupLora(radio, loraConfig)
-
-	oscMessage := osc.OSCMessage{
-		Address: "/lora/button",
-		Args: []osc.OSCArg{
-			{
-				Type:  "i",
-				Value: 0,
-			},
-		},
-	}
-
-	for {
 		if txDone.Load() && buttonPressed.Load() {
 			txDone.Store(false)
 			buttonPressed.Store(false)
@@ -120,7 +139,6 @@ func main() {
 			radio.SetStandby(sx128x.STANDBY_RC)
 			led.Set(true)
 
-			oscMessage.Args[0].Value = int32(time.Now().UnixMilli() / 1000)
 			bytes, err := oscMessage.ToBytes()
 			if err != nil {
 				println("failed to serialize OSC message:", err)
@@ -160,36 +178,36 @@ func main() {
 	}
 }
 
-func SetupLora(radio *sx128x.Device, config lora.Config) {
+func SetupLora(radio *sx128x.Device, config LoRaConfig) {
 	// Switch to standby prior to configuration changes
 
-	circuitMode, _ := radio.GetStatus()
+	circuitMode, _, _ := radio.GetStatus()
 	if circuitMode != sx128x.CIRCUIT_MODE_STDBY_RC {
 		radio.SetStandby(sx128x.STANDBY_RC)
 	}
 	// Clear errors, disable radio interrupts for the moment
 	radio.SetPacketType(sx128x.PACKET_TYPE_LORA)
-	radio.SetCadParams(sx128x.LORA_CAD_08_SYMBOLS)
+	radio.SetCadParams(uint8(sx128x.LORA_CAD_08_SYMBOLS))
 	radio.SetRegulatorMode(sx128x.REGULATOR_DC_DC)
 
-	radio.SetRfFrequency(config.Freq)
+	radio.SetRfFrequency(config.Frequency)
-	radio.SetModulationParams(spreadingFactor(config.Sf), bandwidth(config.Bw), codingRate(config.Cr))
+	radio.SetModulationParamsLoRa(config.SpreadingFactor, config.Bandwidth, config.CodingRate)
 
 	data := [1]uint8{}
-	if config.Sf == lora.SpreadingFactor5 || config.Sf == lora.SpreadingFactor6 {
+	if config.SpreadingFactor == sx128x.LORA_SF_5 || config.SpreadingFactor == sx128x.LORA_SF_6 {
 		data[0] = 0x1E
-	} else if config.Sf == lora.SpreadingFactor7 || config.Sf == lora.SpreadingFactor8 {
+	} else if config.SpreadingFactor == sx128x.LORA_SF_7 || config.SpreadingFactor == sx128x.LORA_SF_8 {
 		data[0] = 0x37
 	} else {
 		data[0] = 0x32
 	}
 	radio.WriteRegister(0x925, data[:])
-	existing := radio.ReadRegister(0x93C)
+	existing, _ := radio.ReadRegister(0x93C)
 	data[0] = existing | 0x01
 	radio.WriteRegister(0x93C, data[:])
 
-	radio.SetTxParams(config.LoraTxPowerDBm, sx128x.RADIO_RAMP_02_US)
+	radio.SetTxParams(config.Power, sx128x.RADIO_RAMP_02_US)
-	radio.SetPacketParamsLoRa(uint32(config.Preamble), config.HeaderType, 0xFF, config.Crc, config.Iq)
+	radio.SetPacketParamsLoRa(config.PreambleLength, config.HeaderType, 0xFF, config.CrcType, config.IqType)
 	var syncWord [2]uint8
 	syncWord[0] = uint8(config.SyncWord >> 8)
 	syncWord[1] = uint8(config.SyncWord & 0x00FF)
@@ -199,7 +217,7 @@ func SetupLora(radio *sx128x.Device, config lora.Config) {
 }
 
 func checkStatus(radio *sx128x.Device, operation string) {
-	circuitMode, commandStatus := radio.GetStatus()
+	circuitMode, commandStatus, _ := radio.GetStatus()
 	if commandStatus != sx128x.COMMAND_STATUS_SUCCESS {
 		println(operation, "-> failed with status:", commandStatus)
 	}
@@ -208,12 +226,12 @@ func checkStatus(radio *sx128x.Device, operation string) {
 	}
 }
 
-func Tx(radio *sx128x.Device, loraConfig lora.Config, data []byte) error {
+func Tx(radio *sx128x.Device, loraConfig LoRaConfig, data []byte) error {
 	if len(data) > 255 {
 		return errors.New("data length exceeds maximum of 255 bytes")
 	}
 	radio.SetStandby(sx128x.STANDBY_RC)
-	radio.SetPacketParamsLoRa(uint32(loraConfig.Preamble), loraConfig.HeaderType, uint8(len(data)&0xFF), loraConfig.Crc, loraConfig.Iq)
+	radio.SetPacketParamsLoRa(loraConfig.PreambleLength, loraConfig.HeaderType, uint8(len(data)&0xFF), loraConfig.CrcType, loraConfig.IqType)
 	radio.SetBufferBaseAddress(0, 0)
 	radio.WriteBuffer(0, data)
 	radio.SetDioIrqParams(sx128x.IRQ_TX_DONE_MASK|sx128x.IRQ_RX_TX_TIMEOUT_MASK, sx128x.IRQ_TX_DONE_MASK|sx128x.IRQ_RX_TX_TIMEOUT_MASK, 0x00, 0x00)
@@ -222,64 +240,11 @@ func Tx(radio *sx128x.Device, loraConfig lora.Config, data []byte) error {
 	return nil
 }
 
-func Rx(radio *sx128x.Device, loraConfig lora.Config) {
+func Rx(radio *sx128x.Device, loraConfig LoRaConfig) {
 	radio.SetStandby(sx128x.STANDBY_RC)
 	radio.SetDioIrqParams(sx128x.IRQ_RX_DONE_MASK|sx128x.IRQ_RX_TX_TIMEOUT_MASK, sx128x.IRQ_RX_DONE_MASK|sx128x.IRQ_RX_TX_TIMEOUT_MASK, 0x00, 0x00)
 	radio.SetBufferBaseAddress(0, 0)
 	radio.ClearIrqStatus(sx128x.IRQ_ALL_MASK)
-	radio.SetRfFrequency(loraConfig.Freq)
+	radio.SetRfFrequency(loraConfig.Frequency)
 	radio.SetRx(sx128x.PERIOD_BASE_4_MS, 250)
 }
-
-func codingRate(cr uint8) uint8 {
-	switch cr {
-	case lora.CodingRate4_5:
-		return sx128x.LORA_CR_4_5
-	case lora.CodingRate4_6:
-		return sx128x.LORA_CR_4_6
-	case lora.CodingRate4_7:
-		return sx128x.LORA_CR_4_7
-	case lora.CodingRate4_8:
-		return sx128x.LORA_CR_4_8
-	default:
-		return 0
-	}
-}
-
-func spreadingFactor(sf uint8) uint8 {
-	switch sf {
-	case lora.SpreadingFactor5:
-		return sx128x.LORA_SF_5
-	case lora.SpreadingFactor6:
-		return sx128x.LORA_SF_6
-	case lora.SpreadingFactor7:
-		return sx128x.LORA_SF_7
-	case lora.SpreadingFactor8:
-		return sx128x.LORA_SF_8
-	case lora.SpreadingFactor9:
-		return sx128x.LORA_SF_9
-	case lora.SpreadingFactor10:
-		return sx128x.LORA_SF_10
-	case lora.SpreadingFactor11:
-		return sx128x.LORA_SF_11
-	case lora.SpreadingFactor12:
-		return sx128x.LORA_SF_12
-	default:
-		return 0
-	}
-}
-
-func bandwidth(bw uint8) uint8 {
-	switch bw {
-	case lora.Bandwidth_1625_0:
-		return sx128x.LORA_BW_1600
-	case lora.Bandwidth_812_5:
-		return sx128x.LORA_BW_800
-	case lora.Bandwidth_406_25:
-		return sx128x.LORA_BW_400
-	case lora.Bandwidth_203_125:
-		return sx128x.LORA_BW_200
-	default:
-		return 0
-	}
-}

node/go.mod

@@ -0,0 +1,3 @@
+module node
+
+go 1.26.2

node/node.go

@@ -0,0 +1,100 @@
+package node
+
+import (
+	"errors"
+)
+
+type Node struct {
+	id             NodeId
+	transport      Transport
+	sequenceNumber uint32
+}
+
+func New(id NodeId, transport Transport) *Node {
+	return &Node{
+		id:        id,
+		transport: transport,
+	}
+}
+
+type NodeId uint8
+
+func (id NodeId) IsBroadcast() bool {
+	return id == 0xFF
+}
+
+func (b *Node) Receive(timeout uint32) (NodeId, uint32, []byte, error) {
+	data, err := b.transport.Rx(timeout)
+	if err != nil {
+		return 0, 0, nil, err
+	}
+	if len(data) < 6 {
+		return 0, 0, nil, errors.New("invalid message length")
+	}
+	sourceId := NodeId(data[0])
+	targetId := NodeId(data[1])
+	if targetId != b.id && !targetId.IsBroadcast() {
+		return 0, 0, nil, nil
+	}
+	seq := uint32(data[2])<<24 | uint32(data[3])<<16 | uint32(data[4])<<8 | uint32(data[5])
+	payload := data[6:]
+	return sourceId, seq, payload, nil
+}
+
+func (b *Node) ReceiveWithAck(timeout uint32) (NodeId, uint32, []byte, error) {
+	data, err := b.transport.Rx(timeout)
+	if err != nil {
+		return 0, 0, nil, err
+	}
+	if len(data) < 6 {
+		return 0, 0, nil, errors.New("invalid message length")
+	}
+	sourceId := NodeId(data[0])
+	targetId := NodeId(data[1])
+	if targetId != b.id && !targetId.IsBroadcast() {
+		return 0, 0, nil, errors.New("message not intended for this node")
+	}
+	seq := uint32(data[2])<<24 | uint32(data[3])<<16 | uint32(data[4])<<8 | uint32(data[5])
+	payload := data[6:]
+	ackMsg := make([]byte, 6)
+	ackMsg[0] = byte(b.id)
+	ackMsg[1] = byte(sourceId)
+	ackMsg[2] = byte(seq >> 24)
+	ackMsg[3] = byte(seq >> 16)
+	ackMsg[4] = byte(seq >> 8)
+	ackMsg[5] = byte(seq)
+	err = b.transport.Tx(ackMsg, timeout)
+	if err != nil {
+		return 0, 0, nil, err
+	}
+	return sourceId, seq, payload, nil
+}
+
+func (b *Node) SendWithAck(target NodeId, payload []byte, timeout uint32) error {
+	if target.IsBroadcast() {
+		return errors.New("cannot send with ack to broadcast address")
+	}
+	msg := make([]byte, 6)
+	msg[0] = byte(b.id)
+	msg[1] = byte(target)
+	sentSeq := b.sequenceNumber
+	msg[2] = byte(sentSeq >> 24)
+	msg[3] = byte(sentSeq >> 16)
+	msg[4] = byte(sentSeq >> 8)
+	msg[5] = byte(sentSeq)
+	b.sequenceNumber++
+	msg = append(msg, payload...)
+	b.transport.Tx(msg, timeout)
+
+	sender, receivedSeq, _, err := b.Receive(timeout)
+	if err != nil {
+		return err
+	}
+	if sender != target {
+		return errors.New("received ACK from unexpected sender")
+	}
+	if receivedSeq != sentSeq {
+		return errors.New("received ACK with unexpected sequence number")
+	}
+	return nil
+}

node/transport.go

@@ -0,0 +1,6 @@
+package node
+
+type Transport interface {
+	Tx(payload []byte, timeout uint32) error
+	Rx(timeout uint32) ([]byte, error)
+}