S7XG Library

Arduino Library for the AcSIP S76G and S78G LoRaWAN (and GPS) chips. It will probably also work with the S76S and S78S (only LoRaWAN) chips.

Description

The S7XG chips by AcSIP are high integrated chips with LoRaWAN and GPS (only the G series).

The S76G/S78G integrates a Semtech SX1276 and a 32-bit ultra-low power Cortex M0+ MCU (STM32L073x), S76G supports global 868 MHz or 915 MHz ISM-Bands. (S78G supports 433MHz or 470 MHz by using SX1278 and the identical MCU with S76G). Besides, S76G/S78G contains a GPS chip – SONY CXD5603GF which is used to receive GPS/GPS+GLONASS signals for positioning.

Dependencies

Some examples are meant to be run on the TTGO T-Watch [Aliexpress] with the LoRa/GPS addon [Aliexpress]. These examples need the AXP202X library to manage the power management chip inside the watch and power the S7XG module.

API Reference

The S7XG class enables Arduino devices to interface the S7XG module using the manufacturer command set. Check the command set reference in the datasheet folder. The class is documented inline and the documentation is generated using doxygen and stored in the docs folder.

Examples

Sending LPP-encoded payload to The Things Network using Activation-by-Personalisation

This example uses the CayenneLPP library. There are several sources for this library but I recommend the ElectronicCats version here: https://github.com/ElectronicCats/CayenneLPP.

#include "S7XG.h"
#include "CayenneLPP.h"

HardwareSerial SerialS7XG(1);
CayenneLPP lpp(32);
S7XG s7xg;

// LoRaWAN credentials as copied from TTN
const char *devAddr = "26011433";
const char *nwkSKey = "5DE49A0F0C9649B8D466B9032DAAB331";
const char *appSKey = "EE0080DAB519CEF94E2EC83A110AA43A";

void setup() {
  
  // Init the hardware serial (this is ESP32 specific)
  SerialS7XG.begin(115200, SERIAL_8N1, 34, 33);
  
  // Init the S7XG module
  s7xg.begin(SerialS7XG);
  s7xg.macPower(14);
  s7xg.macDatarate(DATARATE_EU_SF7BW125);
  s7xg.macADR(false);

  // Join the network in ABP mode
  s7xg.macJoinABP(devAddr, nwkSKey, appSKey);

}

void loop() {

  // Build the payload using CayenneLPP
  lpp.reset();
  lpp.addTemperature(1, 22.5);
  lpp.addBarometricPressure(2, 1073.21);
  lpp.addGPS(3, 52.37365, 4.88650, 2);

  // Sending the data
  s7xg.macSend(lpp.getBuffer(), lpp.getSize());

  // Interval between messages
  delay(30000);

}

There are more examples in the examples folder.

TODO

Future features:

Link budget check (mac set_linkchk)
Auto JOIN
Set delay, datarate and frequency of RX windows
Fine channel and band control
LBT support
Several LoRaWAN 1.0.2 features (dwell, EIRP,...)
GPS TTFF
Getters :)

License

The S7XG library is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

The S7XG library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with the S7XG library. If not, see http://www.gnu.org/licenses/.

leismile / s7xg