Node.js driver for Semtech SX1276/77/78/79 based LoRa radios.
Based on node-sx127x, built on top of @fivdi's onoff and spi-device modules.
- Linux
- SPI hardware with driver installed and enabled
- for raspberry pi, uncomment
dtparam=spi=onin/boot/config.txt
- for raspberry pi, uncomment
- Node.js
| Semtech SX1276/77/78/79 | Generic Linux | Raspberry Pi |
|---|---|---|
| VCC | 3.3V | 3.3V |
| GND | GND | GND |
| SCK | SCK | SCK (pin 11) |
| MISO | MISO | MISO (pin 10) |
| MOSI | MOSI | MOSI (pin 9) |
| NSS | Chip enable/select | CS0 (pin 8) or CS1 (pin 7) |
| NRESET | GPIO pin | GPIO pin |
| DIO0 | GPIO pin | GPIO pin |
npm install sx127x-driverlet SX127x = require("sx127x-driver");
let options = {
// ...
};
let sx127x = new SX127x(options);Supported options:
| Name | Default | Description |
|---|---|---|
spiBus |
0 |
SPI bus to use |
spiDevice |
0 |
SPI chip select/enable to use |
resetPin |
24 |
GPIO pin number of reset pin |
dio0Pin |
25 |
GPIO pin number of DIO0 pin |
frequency |
915e6 |
Frequency of radio in Hz, see setFrequency for supported values (make sure your chip supports the frequency you chose) |
spreadingFactor |
7 |
Spreading factor of radio, see setSpreadingFactor for supported values (spreading factors are orthogonal, so make sure they match when trying to communicate from one chip to another) |
signalBandwidth |
125E3 |
Signal bandwidth of radio in Hz, see setSignalBandwidth for supported values |
codingRate |
4 / 5 |
Coding rate of radio, see setCodingRate for supported values |
preambleLength |
8 |
Preamble length of radio, see setPreambleLength for supported values |
syncWord |
0x12 |
Sync word of radio, see setSyncWord for supported values |
txPower |
17 |
TX power of radio, see setTxPower for supported values |
crc |
false |
Enable or disable CRC usage |
tempCompensationFactor |
false |
compensation factor for temperature measurements in degrees celsius (+- some degrees) |
debug |
false |
enable / disable debug output |
invertIqReg |
false |
inverts IQ register on call to open() |
Open and configure the device:
try {
await sx127x.open();
} catch (err) {
console.log("Failure to open device: " + err);
}Close the device:
try {
await sx127x.close();
} catch (err) {
console.log("Close failure: " + err);
process.exit();
}try {
await sx127x.write(new Buffer("hello " + count++));
console.log("successfully sent");
} catch (err) {
console.log("Fail to send: " + err);
}try {
let packetLength = await sx127x.receiveSingle();
if (packetLength > 0) {
let incoming = "";
while (await sx127x.available()) {
incoming += String.fromCharCode(await sx127x.read());
}
}
} catch (err) {
console.log("Fail to receive: " + err);
}try {
await sx127x.open();
await sx127x.setContinuousReceiveMode();
} catch (err) {
console.log("Fail to put into continuous receive mode: " + err);
}
sx127x.on("data", function (data, rssi, snr) {
console.log("data: " + data.toString() + ", rssi: " + rssi);
});Put the radio in sleep mode.
try {
await sx127x.sleep();
} catch (err) {
console.log("Fail to put into sleep mode: " + err);
}Put the radio in stand by mode.
try {
await sx127x.standBy();
} catch (err) {
console.log("Fail to put into stand by: " + err);
}Change the TX power of the radio.
try {
await sx127x.setTxPower(txPower);
} catch (err) {
console.log(err);
}txPower- TX power in dB, defaults to17
Supported values are between 2 and 17.
Change the frequency of the radio.
try {
await sx127x.setFrequency(frequency);
} catch (err) {
console.log(err);
}frequency- frequency in Hz (433E6,866E6,915E6)
Change the spreading factor of the radio.
try {
await sx127x.setSpreadingFactor(spreadingFactor);
} catch (err) {
console.log(err);
}spreadingFactor- spreading factor, defaults to7
Supported values are between 6 and 12. If a spreading factor of 6 is set, implicit header mode must be used to transmit and receive packets.
Change the signal bandwidth of the radio.
try {
await sx127x.setSignalBandwidth(signalBandwidth);
} catch (err) {
console.log(err);
}signalBandwidth- signal bandwidth in Hz, defaults to125E3.
Supported values are 7.8E3, 10.4E3, 15.6E3, 20.8E3, 31.25E3, 41.7E3, 62.5E3, 125E3, 250E3 and 500E3.
Change the coding rate of the radio.
try {
await sx127x.setCodingRate(codingRate);
} catch (err) {
console.log(err);
}codingRate- coding rate, defaults to4/5
Supported values are 4/5, 4/6, 4/7 and 4/8.
Change the preamble length of the radio.
try {
await sx127x.setPreambleLength(preambleLength);
} catch (err) {
console.log(err);
}preambleLength- preamble length in symbols, defaults to8
Supported values are between 6 and 65535.
Change the sync word of the radio.
try {
await sx127x.setSyncWord(syncWord);
} catch (err) {
console.log(err);
}syncWord- byte value to use as the sync word, defaults to0x34
Enable or disable CRC usage, by default a CRC is not used.
try {
await sx127x.setCrc(crc);
} catch (err) {
console.log(err);
}crc-trueto enable CRC,falseto disable
Generate a random byte, based on the Wideband RSSI measurement.
try {
let random = await sx127x.readRandom(crc);
} catch (err) {
console.log(err);
}See examples folder.
This library is licensed under the MIT Licence.