LoRaSensor
Inhaltsverzeichnis |
Anleitung für einen schnell zusammengebauten Sensor-Knoten mit LoRa-Interface
Hardware-Stückliste
- Ein auf der ESP32-Architektur basierendes Developer Board mit LoRa-Funkmodul (Detaillierte Vorstellung bei Heise), am besten mit OLED-Display, in Europa sind die Frequenzen um 433MHz oder 868MHz möglich. Unser erster Gateway arbeitet auf 868MHz. Preise je nach Quelle zwischen 10 USD und 35 EUR.
- http://www.heltec.cn/project/wifi-lora-32/
- https://www.amazon.de/gp/product/B078M74NNN/
- https://www.amazon.de/gp/product/B076T28KWG/
- https://www.thethingsnetwork.org/forum/t/big-esp32-sx127x-topic-part-1/10247
- https://de.aliexpress.com/item/ESP32-0-96-Inch-Blue-OLED-Display-Bluetooth-WIFI-CP2102-LoRa-Kit-32-Module-Internet-Development/32840325780.html
- Sensor - wir wählen hier einen MQ-135, der eine recht allgemeine Aussage zur Luftqualität liefert (Benzol, Alkohol, Rauch, Ammoniak, Sulfide, Aromaten), ab 2 EUR beim Chinesen
- ADS1115 AD-Wandler mit I2C (eigentlich könnte das Developer-Board AD-Wandeln auch direkt selbst, aber der oben beschriebene Typ verträgt nur 3,3V am Eingang und der MQ-135 liefert zwischen 0 und 5V am Ausgang, je nach Konzentration)
- Optional Breadboard und Kabel
Entwicklungsumgebung einrichten
- Arduino IDE. Das hier verwendete Entwicklungs-Board mit ESP32 lässt sich unter anderem mittels Arduino IDE programmieren
- Eventuell braucht das entsprechende Betriebssystem einen Treiber für den auf dem Entwicklungs-Board vorhandenen USB-Serial-Converter
- Arduino Core API für ESP32 installieren
- In der Arduino IDE Treiber fürs Board installieren
Software
- Hier fehlt noch viel - die Messwerte auf dem Bild stammen von einem MQ-135 an einem Raspberry PI
- C-Code (Arduino-Style) zum Auslesen des Sensors und Versenden des Ergebnisses per LoRaWAN
- InfluxDB und Grafana
<syntaxhighlight lang="c">
- include <Arduino.h>
- include <U8g2lib.h>
//https://github.com/olikraus/u8g2
- include "esp_system.h"
- include <lmic.h>
- include <hal/hal.h>
- include <SPI.h>
- ifdef U8X8_HAVE_HW_I2C
- include <Wire.h>
- endif
// LoRaWAN NwkSKey, network session key // This is the default Semtech key, which is used by the prototype TTN // network initially. static const PROGMEM u1_t NWKSKEY[16] = { 0x2B, 0x7E, 0x15, 0x16, 0x28, 0xAE, 0xD2, 0xA6, 0xAB, 0xF7, 0x15, 0x88, 0x09, 0xCF, 0x4F, 0x3C };
// LoRaWAN AppSKey, application session key // This is the default Semtech key, which is used by the prototype TTN // network initially. static const u1_t PROGMEM APPSKEY[16] = { 0x2B, 0x7E, 0x15, 0x16, 0x28, 0xAE, 0xD2, 0xA6, 0xAB, 0xF7, 0x15, 0x88, 0x09, 0xCF, 0x4F, 0x3C };
// LoRaWAN end-device address (DevAddr) // See http://thethingsnetwork.org/wiki/AddressSpace static const u4_t DEVADDR = 0x03FF0001 ; // <-- Change this address for every node!
int sensorPin = 34; // select the input pin for the potentiometer int ledPin = 25; // select the pin for the LED int sensorValue = 0; // variable to store the value coming from the sensor int counter = 0;
// These callbacks are only used in over-the-air activation, so they are // left empty here (we cannot leave them out completely unless // DISABLE_JOIN is set in config.h, otherwise the linker will complain). void os_getArtEui (u1_t* buf) { } void os_getDevEui (u1_t* buf) { } void os_getDevKey (u1_t* buf) { }
uint8_t mydata[] = "Empty"; static osjob_t sendjob;
// Schedule TX every this many seconds (might become longer due to duty // cycle limitations). const unsigned TX_INTERVAL = 60;
// Pin mapping const lmic_pinmap lmic_pins = {
.nss = 6, .rxtx = LMIC_UNUSED_PIN, .rst = 5, .dio = {2, 3, 4},
};
void onEvent (ev_t ev) {
Serial.print(os_getTime()); Serial.print(": "); switch(ev) { case EV_SCAN_TIMEOUT: Serial.println(F("EV_SCAN_TIMEOUT")); break; case EV_BEACON_FOUND: Serial.println(F("EV_BEACON_FOUND")); break; case EV_BEACON_MISSED: Serial.println(F("EV_BEACON_MISSED")); break; case EV_BEACON_TRACKED: Serial.println(F("EV_BEACON_TRACKED")); break; case EV_JOINING: Serial.println(F("EV_JOINING")); break; case EV_JOINED: Serial.println(F("EV_JOINED")); break; case EV_RFU1: Serial.println(F("EV_RFU1")); break; case EV_JOIN_FAILED: Serial.println(F("EV_JOIN_FAILED")); break; case EV_REJOIN_FAILED: Serial.println(F("EV_REJOIN_FAILED")); break; break; case EV_TXCOMPLETE: Serial.println(F("EV_TXCOMPLETE (includes waiting for RX windows)")); if(LMIC.dataLen) { // data received in rx slot after tx Serial.print(F("Data Received: ")); Serial.write(LMIC.frame+LMIC.dataBeg, LMIC.dataLen); Serial.println(); } // Schedule next transmission os_setTimedCallback(&sendjob, os_getTime()+sec2osticks(TX_INTERVAL), do_send); break; case EV_LOST_TSYNC: Serial.println(F("EV_LOST_TSYNC")); break; case EV_RESET: Serial.println(F("EV_RESET")); break; case EV_RXCOMPLETE: // data received in ping slot Serial.println(F("EV_RXCOMPLETE")); break; case EV_LINK_DEAD: Serial.println(F("EV_LINK_DEAD")); break; case EV_LINK_ALIVE: Serial.println(F("EV_LINK_ALIVE")); break; default: Serial.println(F("Unknown event")); break; }
}
void do_send(osjob_t* j){
// Check if there is not a current TX/RX job running if (LMIC.opmode & OP_TXRXPEND) { Serial.println(F("OP_TXRXPEND, not sending")); } else { // Prepare upstream data transmission at the next possible time. LMIC_setTxData2(1, mydata, sizeof(mydata)-1, 0); Serial.println(F("Packet queued")); } // Next TX is scheduled after TX_COMPLETE event.
}
/*
U8glib Example Overview: Frame Buffer Examples: clearBuffer/sendBuffer. Fast, but may not work with all Arduino boards because of RAM consumption Page Buffer Examples: firstPage/nextPage. Less RAM usage, should work with all Arduino boards. U8x8 Text Only Example: No RAM usage, direct communication with display controller. No graphics, 8x8 Text only.
- /
// U8g2 Contructor List (Frame Buffer) // The complete list is available here: https://github.com/olikraus/u8g2/wiki/u8g2setupcpp
U8G2_SSD1306_128X64_NONAME_F_SW_I2C u8g2(U8G2_R0, /* clock=*/ 15, /* data=*/ 4, /* reset=*/ 16);
void u8g2_prepare(void) {
u8g2.setFont(u8g2_font_6x10_tf); //https://github.com/olikraus/u8g2/wiki/fntgrpx11 u8g2.setFontRefHeightExtendedText(); u8g2.setDrawColor(1); u8g2.setFontPosTop(); u8g2.setFontDirection(0);
}
- define opennetlogobw_width 64
- define opennetlogobw_height 64
static unsigned char opennetlogobw_bits[] = {
0x00, 0x00, 0x80, 0xff, 0x1f, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf8, 0x07, 0xfc, 0x03, 0x00, 0x00, 0x00, 0x00, 0x0f, 0x00, 0x00, 0x1f, 0x00, 0x00, 0x00, 0xe0, 0x01, 0x00, 0x00, 0x78, 0x00, 0x00, 0x00, 0x38, 0x00, 0x00, 0x00, 0xc0, 0x03, 0x00, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x07, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1c, 0x00, 0x00, 0x00, 0xc0, 0xff, 0x3f, 0x00, 0x70, 0x00, 0x00, 0x00, 0xf8, 0x00, 0xf0, 0x03, 0xc0, 0x00, 0x00, 0x00, 0x0f, 0x00, 0x00, 0x0f, 0x80, 0x01, 0x00, 0xc0, 0x01, 0x00, 0x00, 0x38, 0x00, 0x03, 0x00, 0x40, 0x00, 0x00, 0x00, 0xe0, 0x00, 0x06, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80, 0x03, 0x1c, 0x00, 0x00, 0x00, 0xfc, 0x03, 0x00, 0x06, 0x38, 0x00, 0x00, 0xc0, 0xff, 0x7f, 0x00, 0x1c, 0x30, 0x00, 0x00, 0x78, 0x00, 0xe0, 0x01, 0x38, 0x60, 0x00, 0x00, 0x0e, 0x00, 0x00, 0x07, 0x60, 0xc0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1c, 0xc0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xe0, 0x80, 0x01, 0x00, 0x00, 0x00, 0xfe, 0x07, 0x80, 0x01, 0x01, 0x00, 0x00, 0xc0, 0x07, 0x3c, 0x00, 0x03, 0x00, 0x00, 0x00, 0x60, 0x00, 0xe0, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80, 0x01, 0x06, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x07, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0c, 0x00, 0x00, 0x00, 0x00, 0x00, 0xe0, 0x00, 0x18, 0x00, 0x00, 0x00, 0x00, 0x00, 0xfe, 0x07, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x1c, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x38, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x60, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x78, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xfe, 0x01, 0x80, 0x1f, 0x00, 0x00, 0x00, 0x00, 0xff, 0x03, 0xc0, 0x3f, 0x00, 0x00, 0x00, 0x00, 0xff, 0x07, 0xe0, 0x7f, 0x00, 0x00, 0x00, 0x00, 0xff, 0x07, 0xe0, 0x7f, 0x00, 0x00, 0x00, 0x02, 0xff, 0x07, 0xe0, 0xff, 0x00, 0x00, 0x00, 0x04, 0xfe, 0x03, 0xe0, 0x7f, 0x00, 0x00, 0x00, 0x0c, 0xfc, 0x03, 0xe0, 0x7f, 0x00, 0x00, 0x00, 0x38, 0xf0, 0x00, 0xc0, 0x3f, 0x80, 0x00, 0x00, 0x78, 0x00, 0x00, 0x00, 0x06, 0xc0, 0x00, 0x00, 0xf0, 0x01, 0x00, 0x01, 0x00, 0x60, 0x00, 0x00, 0xf0, 0x07, 0x10, 0x1e, 0x00, 0x78, 0x00, 0x00, 0xe0, 0x3f, 0x0f, 0xf8, 0x07, 0x7e, 0x00, 0x00, 0xe0, 0xff, 0x07, 0xf0, 0xff, 0x7f, 0x00, 0x00, 0xe0, 0xff, 0x07, 0xc0, 0xff, 0x7f, 0x00, 0x00, 0xe0, 0xff, 0x03, 0x80, 0xff, 0x3f, 0x00, 0x00, 0xe0, 0xff, 0x01, 0x00, 0xff, 0x3f, 0x00, 0x00, 0xf0, 0xff, 0x01, 0x00, 0xfe, 0x3f, 0x00, 0x00, 0xf8, 0xff, 0x00, 0x00, 0xfe, 0x3f, 0x00, 0x00, 0xfe, 0xff, 0x00, 0x00, 0xfc, 0x7f, 0x00, 0x80, 0xff, 0xff, 0x00, 0x00, 0xfc, 0x7f, 0x00, 0xe0, 0x03, 0xff, 0x00, 0x00, 0xfe, 0xff, 0x00, 0x04, 0x00, 0xf8, 0x00, 0x00, 0xfe, 0xff, 0x00, 0x00, 0x00, 0xf0, 0x00, 0x00, 0xff, 0xff, 0x01, 0x00, 0x00, 0xe0, 0x00, 0x00, 0x3f, 0xe0, 0x01, 0x00, 0x00, 0xc0, 0x00, 0x80, 0x0f, 0x80, 0x03, 0x00, 0x00, 0x80, 0x00, 0xc0, 0x03, 0x00, 0x06, 0x00, 0x00, 0x80, 0x00, 0xe0, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x01, 0x30, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
void u8g2_bitmap_modes(uint8_t transparent) {
const uint8_t frame_size = 24;
u8g2.setDrawColor(1);// Black u8g2.drawXBMP(0, 0, opennetlogobw_width, opennetlogobw_height, opennetlogobw_bits);
}
void draw(void) {
u8g2_prepare(); u8g2_bitmap_modes(0);
}
void setup(void) {
u8g2.begin(); pinMode(ledPin, OUTPUT); pinMode(sensorPin, INPUT); Serial.begin(115200); Serial.println("Programm gestartet!");
#ifdef VCC_ENABLE // For Pinoccio Scout boards pinMode(VCC_ENABLE, OUTPUT); digitalWrite(VCC_ENABLE, HIGH); delay(1000); #endif
// LMIC init os_init(); // Reset the MAC state. Session and pending data transfers will be discarded. LMIC_reset();
// Set static session parameters. Instead of dynamically establishing a session // by joining the network, precomputed session parameters are be provided. #ifdef PROGMEM // On AVR, these values are stored in flash and only copied to RAM // once. Copy them to a temporary buffer here, LMIC_setSession will // copy them into a buffer of its own again. uint8_t appskey[sizeof(APPSKEY)]; uint8_t nwkskey[sizeof(NWKSKEY)]; memcpy_P(appskey, APPSKEY, sizeof(APPSKEY)); memcpy_P(nwkskey, NWKSKEY, sizeof(NWKSKEY)); LMIC_setSession (0x1, DEVADDR, nwkskey, appskey); #else // If not running an AVR with PROGMEM, just use the arrays directly LMIC_setSession (0x1, DEVADDR, NWKSKEY, APPSKEY); #endif
// Set up the channels used by the Things Network, which corresponds // to the defaults of most gateways. Without this, only three base // channels from the LoRaWAN specification are used, which certainly // works, so it is good for debugging, but can overload those // frequencies, so be sure to configure the full frequency range of // your network here (unless your network autoconfigures them). // Setting up channels should happen after LMIC_setSession, as that // configures the minimal channel set. LMIC_setupChannel(0, 868100000, DR_RANGE_MAP(DR_SF12, DR_SF7), BAND_CENTI); // g-band LMIC_setupChannel(1, 868300000, DR_RANGE_MAP(DR_SF12, DR_SF7B), BAND_CENTI); // g-band LMIC_setupChannel(2, 868500000, DR_RANGE_MAP(DR_SF12, DR_SF7), BAND_CENTI); // g-band LMIC_setupChannel(3, 867100000, DR_RANGE_MAP(DR_SF12, DR_SF7), BAND_CENTI); // g-band LMIC_setupChannel(4, 867300000, DR_RANGE_MAP(DR_SF12, DR_SF7), BAND_CENTI); // g-band LMIC_setupChannel(5, 867500000, DR_RANGE_MAP(DR_SF12, DR_SF7), BAND_CENTI); // g-band LMIC_setupChannel(6, 867700000, DR_RANGE_MAP(DR_SF12, DR_SF7), BAND_CENTI); // g-band LMIC_setupChannel(7, 867900000, DR_RANGE_MAP(DR_SF12, DR_SF7), BAND_CENTI); // g-band LMIC_setupChannel(8, 868800000, DR_RANGE_MAP(DR_FSK, DR_FSK), BAND_MILLI); // g2-band // TTN defines an additional channel at 869.525Mhz using SF9 for class B // devices' ping slots. LMIC does not have an easy way to define set this // frequency and support for class B is spotty and untested, so this // frequency is not configured here.
// Disable link check validation LMIC_setLinkCheckMode(0);
// Set data rate and transmit power (note: txpow seems to be ignored by the library) LMIC_setDrTxpow(DR_SF7,14);
// Start job do_send(&sendjob);
}
void loop(void) {
digitalWrite(ledPin, LOW); u8g2.clearBuffer(); draw(); sensorValue = analogRead(sensorPin); u8g2.setFont(u8g2_font_6x10_tf); char c[64]; String str; str = String(sensorValue); Serial.println(str); str.getBytes(mydata, 64); // mydata will be sent in do_send() which is also called in case we receive a EV_TXCOMPLETE event str.toCharArray(c, 64); u8g2.drawStr(75,0, "Sensor"); u8g2.drawStr(75,10, "readout:"); u8g2.drawStr(75,20, c); u8g2.drawStr(75,34, "LoRaWAN"); u8g2.drawStr(75,44, "message"); str = String(counter); Serial.println(str); str.toCharArray(c, 64); u8g2.drawStr(75,54, c); counter++; u8g2.sendBuffer(); delay(2500); digitalWrite(ledPin, HIGH); delay(2500);
} </syntaxhighlight>