add SPI driver for semtech sx128x chips

examples/sx128x/lora_rx/main.go

@@ -0,0 +1,106 @@
+package main
+
+import (
+	"errors"
+	"machine"
+	"runtime"
+	"time"
+
+	"tinygo.org/x/drivers/sx128x"
+)
+
+var (
+	// pin mapping specific to the lilygo t3s3, change as needed for your board
+	sdoPin   = machine.GPIO6
+	sdiPin   = machine.GPIO3
+	sckPin   = machine.GPIO5
+	nssPin   = machine.GPIO7
+	busyPin  = machine.GPIO36
+	resetPin = machine.GPIO8
+	dio1Pin  = machine.GPIO9
+)
+
+func setupPins() {
+	nssPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	nssPin.Set(true)
+
+	resetPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	resetPin.Set(true)
+
+	busyPin.Configure(machine.PinConfig{Mode: machine.PinInput})
+	dio1Pin.Configure(machine.PinConfig{Mode: machine.PinInput})
+}
+
+func main() {
+	setupPins()
+
+	spi := machine.SPI0
+	spi.Configure(machine.SPIConfig{
+		Mode:      0,
+		Frequency: 8 * 1e6,
+		SDO:       sdoPin,
+		SDI:       sdiPin,
+		SCK:       sckPin,
+	})
+
+	radio := sx128x.New(
+		spi,
+		nssPin,
+		resetPin,
+		busyPin,
+	)
+
+	radio.WaitWhileBusy(time.Second)
+	SetupLora(radio)
+
+	for {
+		data, err := Rx(radio)
+		if err != nil {
+			println("failed to receive:", err)
+		} else {
+			println("received:", string(data))
+		}
+	}
+}
+
+func SetupLora(radio *sx128x.Device) {
+	radio.SetStandby(sx128x.STANDBY_RC)
+	radio.SetPacketType(sx128x.PACKET_TYPE_LORA)
+	radio.SetRegulatorMode(sx128x.REGULATOR_DC_DC)
+
+	radio.SetRfFrequency(2400000000) // 2.4Ghz
+	radio.SetModulationParamsLoRa(sx128x.LORA_SF_9, sx128x.LORA_BW_1600, sx128x.LORA_CR_4_7)
+
+	// section 14.4.1 shows required register setting for setting up LoRa operations. These depend on the chosen spreading factor.
+	radio.WriteRegister(0x925, []byte{0x32})
+	radio.WriteRegister(0x93C, []byte{0x01})
+
+	radio.SetTxParams(13, sx128x.RADIO_RAMP_02_US)
+	radio.SetPacketParamsLoRa(12, sx128x.LORA_HEADER_EXPLICIT, 0xFF, sx128x.LORA_CRC_DISABLE, sx128x.LORA_IQ_STD)
+	radio.WriteRegister(sx128x.REG_LORA_SYNC_WORD_MSB, []byte{0x14, 0x24}) // full sync word is 0x1424
+
+}
+
+func Rx(radio *sx128x.Device) ([]byte, error) {
+	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.SetRx(sx128x.PERIOD_BASE_4_MS, 250) // 4ms * 250 = 1s
+	// busy wait for IRQ indication
+	for dio1Pin.Get() == false {
+		runtime.Gosched()
+	}
+	irqStatus, _ := radio.GetIrqStatus()
+	if irqStatus&sx128x.IRQ_RX_DONE_MASK != 0 {
+		payloadLength, bufferOffset, err := radio.GetRxBufferStatus()
+		if err != nil {
+			return nil, err
+		}
+		data, err := radio.ReadBuffer(bufferOffset, payloadLength)
+		return data, nil
+	} else if irqStatus&sx128x.IRQ_RX_TX_TIMEOUT_MASK != 0 {
+		return nil, errors.New("rx timeout")
+	}
+	return nil, errors.New("unexpected IRQ status")
+}

examples/sx128x/lora_tx/main.go

@@ -0,0 +1,96 @@
+package main
+
+import (
+	"errors"
+	"machine"
+	"runtime"
+	"time"
+
+	"tinygo.org/x/drivers/sx128x"
+)
+
+var (
+	// pin mapping specific to the lilygo t3s3, change as needed for your board
+	sdoPin   = machine.GPIO6
+	sdiPin   = machine.GPIO3
+	sckPin   = machine.GPIO5
+	nssPin   = machine.GPIO7
+	busyPin  = machine.GPIO36
+	resetPin = machine.GPIO8
+	dio1Pin  = machine.GPIO9
+)
+
+func setupPins() {
+	nssPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	nssPin.Set(true)
+
+	resetPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	resetPin.Set(true)
+
+	busyPin.Configure(machine.PinConfig{Mode: machine.PinInput})
+	dio1Pin.Configure(machine.PinConfig{Mode: machine.PinInput})
+}
+
+func main() {
+	setupPins()
+
+	spi := machine.SPI0
+	spi.Configure(machine.SPIConfig{
+		Mode:      0,
+		Frequency: 8 * 1e6,
+		SDO:       sdoPin,
+		SDI:       sdiPin,
+		SCK:       sckPin,
+	})
+
+	radio := sx128x.New(
+		spi,
+		nssPin,
+		resetPin,
+		busyPin,
+	)
+
+	radio.WaitWhileBusy(time.Second)
+	SetupLora(radio)
+
+	for {
+		Tx(radio, []byte("Hello, world!"))
+		time.Sleep(1 * time.Second)
+	}
+}
+
+func SetupLora(radio *sx128x.Device) {
+	radio.SetStandby(sx128x.STANDBY_RC)
+	radio.SetPacketType(sx128x.PACKET_TYPE_LORA)
+	radio.SetRegulatorMode(sx128x.REGULATOR_DC_DC)
+
+	radio.SetRfFrequency(2400000000) // 2.4Ghz
+	radio.SetModulationParamsLoRa(sx128x.LORA_SF_9, sx128x.LORA_BW_1600, sx128x.LORA_CR_4_7)
+
+	// section 14.4.1 shows required register setting for setting up LoRa operations. These depend on the chosen spreading factor.
+	radio.WriteRegister(0x925, []byte{0x32})
+	radio.WriteRegister(0x93C, []byte{0x01})
+
+	radio.SetTxParams(13, sx128x.RADIO_RAMP_02_US)
+	radio.SetPacketParamsLoRa(12, sx128x.LORA_HEADER_EXPLICIT, 0xFF, sx128x.LORA_CRC_DISABLE, sx128x.LORA_IQ_STD)
+	radio.WriteRegister(sx128x.REG_LORA_SYNC_WORD_MSB, []byte{0x14, 0x24}) // full sync word is 0x1424
+
+}
+
+func Tx(radio *sx128x.Device, data []byte) error {
+	if len(data) > 255 {
+		return errors.New("data length exceeds maximum of 255 bytes")
+	}
+	radio.SetStandby(sx128x.STANDBY_RC)
+	radio.SetPacketParamsLoRa(12, sx128x.LORA_HEADER_EXPLICIT, uint8(len(data)&0xFF), sx128x.LORA_CRC_DISABLE, sx128x.LORA_IQ_STD)
+	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)
+	radio.ClearIrqStatus(sx128x.IRQ_ALL_MASK)
+	radio.SetTx(sx128x.PERIOD_BASE_4_MS, 250) // 4ms * 250 = 1s
+	// busy wait for IRQ indication
+	for dio1Pin.Get() == false {
+		runtime.Gosched()
+	}
+	return nil
+}

sx128x/README.md

@@ -0,0 +1,7 @@
+# SX128x Radio
+Radio from Semtech in the 2.4 GHz band. This driver uses SPI to communicate with the radio instead of the alternative UART interface.
+
+## Supported Chips
+- [SX1280](https://www.semtech.com/products/wireless-rf/lora-connect/sx1280)
+- [SX1281](https://www.semtech.com/products/wireless-rf/lora-connect/sx1281) 
+

sx128x/commands.go

@@ -0,0 +1,52 @@
+package sx128x
+
+const (
+	// SX128X SPI commands
+	cmdGetStatus = uint8(0xC0)
+
+	// Register Access Operations
+	cmdWriteRegister = uint8(0x18)
+	cmdReadRegister  = uint8(0x19)
+
+	// Data Buffer Operations
+	cmdWriteBuffer = uint8(0x1A)
+	cmdReadBuffer  = uint8(0x1B)
+
+	// Radio Operation Modes
+	cmdSetSleep              = uint8(0x84)
+	cmdSetStandby            = uint8(0x80)
+	cmdSetFS                 = uint8(0xC1)
+	cmdSetTx                 = uint8(0x83)
+	cmdSetRx                 = uint8(0x82)
+	cmdSetRxDutyCycle        = uint8(0x94)
+	cmdSetLongPreamble       = uint8(0x9B)
+	cmdSetCAD                = uint8(0xC5)
+	cmdSetTxContinuousWave   = uint8(0xD1)
+	cmdSetContinuousPreamble = uint8(0xD2)
+	cmdSetAutoTx             = uint8(0x98)
+	cmdSetAutoFS             = uint8(0x9E)
+
+	// Radio Configuration
+	cmdSetPacketType        = uint8(0x8A)
+	cmdGetPacketType        = uint8(0x03)
+	cmdSetRFFrequency       = uint8(0x86)
+	cmdSetTxParams          = uint8(0x8E)
+	cmdSetCADParams         = uint8(0x88)
+	cmdSetBufferBaseAddress = uint8(0x8F)
+	cmdSetModulationParams  = uint8(0x8B)
+	cmdSetPacketParams      = uint8(0x8C)
+
+	// Communication Status Information
+	cmdGetRxBufferStatus = uint8(0x17)
+	cmdGetPacketStatus   = uint8(0x1D)
+	cmdGetRSSIInst       = uint8(0x1F)
+
+	// IRQ Handling
+	cmdSetDIOIRQParams = uint8(0x8D)
+	cmdGetIRQStatus    = uint8(0x15)
+	cmdClearIRQStatus  = uint8(0x97)
+
+	// Miscellaneous
+	cmdSetRegulatorMode = uint8(0x96)
+	cmdSetSaveContext   = uint8(0xD5)
+)