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jwetzellCopilot
jwetzell
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Copilot
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add SPI driver for semtech sx128x chips (#864)
* add SPI driver for semtech sx128x chips Co-authored-by: Copilot <copilot@github.com> * handle busy loop better * switch to time based busy timeout Co-authored-by: Copilot <copilot@github.com> * comment functions * start on using types for function inputs * use types where applicable and align with datasheet more Co-authored-by: Copilot <copilot@github.com> * work on exporting less constants * only export "actionable" errors * combine identical constants * add crude lora rx and tx examples * change from type aliases to local types --------- Co-authored-by: Copilot <copilot@github.com>
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‎examples/sx128x/lora_rx/main.go‎

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

‎examples/sx128x/lora_tx/main.go‎

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

‎sx128x/README.md‎

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# SX128x Radio
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Radio from Semtech in the 2.4 GHz band. This driver uses SPI to communicate with the radio instead of the alternative UART interface.
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## Supported Chips
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- [SX1280](https://www.semtech.com/products/wireless-rf/lora-connect/sx1280)
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- [SX1281](https://www.semtech.com/products/wireless-rf/lora-connect/sx1281)
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‎sx128x/commands.go‎

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

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