Hi All,
I’m testing an ESP32 node using the following code:
Single-Channel TTN ABP Device
By: Jim Lindblom
SparkFun Electronics
Date: July 31, 2018
License: This code is public domain but you buy me a beer if you use this and we meet someday (Beerware license).
Feel like supporting our work? Buy a board from SparkFun!
https://sparkle.sparkfun.com/sparkle/storefront_products/14893
This example demonstrates how to use the SparkX ESP32 LoRa 1-CH Gateway as a LoRaWAN device.
It is configured to transmit on a single channel -- making it compatible with the same board
set up as a gateway.
Library Dependencies:
arduino-lmic: https://github.com/mcci-catena/arduino-lmic
To use the example, ensure that you've first configured the arduino-lmic library as required.
Then create an application and device on the Things Network. Configure it for ABP activation.
Then copy the NETWORK SESSION KEY, APP SESSION KEY, and DEVICE ADDRESS into the global variables
towards the top of this sketch.
Once uploaded, press the "0" button to trigger a LoRa send. The device will send "Hello, World"
on the set frequency, hoping your gateway hears it.
This example is based on ttn-abp by: Thomas Telkamp and Matthijs Kooijman
*/
// Include the arduino-lmic library:
#include <lmic.h>
#include <hal/hal.h>
#include <SPI.h>
// Below sets the trigger for sending a new message to a gateway.
// Either or both can be enabled (in which case pressing the button will restart the timer)
#define SEND_BY_BUTTON 1 // Send a message when button "0" is pressed
#define SEND_BY_TIMER 1 // Send a message every TX_INTERVAL seconds
// LoRaWAN NwkSKey, network session key
// This is the default Semtech key, which is used by the early prototype TTN
// network.
static const PROGMEM u1_t NWKSKEY[16] = { XXX };
// LoRaWAN AppSKey, application session key
// This is the default Semtech key, which is used by the early prototype TTN
// network.
static const u1_t PROGMEM APPSKEY[16] = { XXX };
// LoRaWAN end-device address (DevAddr)
static const u4_t DEVADDR = 0xXXX;
// 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) { }
static uint8_t mydata[] = "Hello, world!";
static osjob_t sendjob;
// Pin mapping for the SparkX ESP32 LoRa 1-CH Gateway
const lmic_pinmap lmic_pins = {
.nss = 18,
.rxtx = LMIC_UNUSED_PIN,
.rst = 14,
.dio = {26, 34, 35},
};
// If send-by-timer is enabled, define a tx interval
#ifdef SEND_BY_TIMER
#define TX_INTERVAL 5 // Message send interval in seconds
#endif
// State machine event handler
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;
case EV_TXCOMPLETE:
digitalWrite(LED_BUILTIN, LOW); // Turn off LED after send is complete
Serial.println(F("EV_TXCOMPLETE (includes waiting for RX windows)"));
if (LMIC.txrxFlags & TXRX_ACK)
Serial.println(F("Received ack"));
if (LMIC.dataLen) {
Serial.println(F("Received "));
Serial.println(LMIC.dataLen);
Serial.println(F(" bytes of payload"));
}
#ifdef SEND_BY_TIMER
// Schedule the next transmission
os_setTimedCallback(&sendjob, os_getTime() + sec2osticks(TX_INTERVAL), do_send);
#endif
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;
}
}
// Transmit data from mydata
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 {
digitalWrite(LED_BUILTIN, HIGH); // Turn on LED while sending
// Prepare upstream data transmission at the next possible time.
LMIC_setTxData2(1, mydata, sizeof(mydata) - 1, 0);
Serial.println(F("Packet queued"));
}
}
void setup() {
Serial.begin(115200);
// Set button pin as input
#ifdef SEND_BY_BUTTON
pinMode(0, INPUT);
#endif
// Configure built-in LED -- will illuminate when sending
pinMode(LED_BUILTIN, OUTPUT);
digitalWrite(LED_BUILTIN, LOW);
// LMIC init
os_init();
// Reset the MAC state. Session and pending data transfers will be discarded.
LMIC_reset();
// 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)];
(void)memcpy_P(appskey, APPSKEY, sizeof(APPSKEY));
(void)memcpy_P(nwkskey, NWKSKEY, sizeof(NWKSKEY));
LMIC_setSession(0x1, DEVADDR, nwkskey, appskey);
// 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.
// NA-US channels 0-71 are configured automatically
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);
// TTN uses SF9 for its RX2 window.
LMIC.dn2Dr = DR_SF9;
// Set data rate and transmit power for uplink (note: txpow seems to be ignored by the library)
LMIC_setDrTxpow(DR_SF7, 14);
//disable all channels except channel 0 (868.1 MHz) for communication with single channel gateway
for (int i=1;i<=8;i++)LMIC_disableChannel(i);
// Start job -- Transmit a message on begin
do_send(&sendjob);
}
void loop() {
os_runloop_once();
#ifdef SEND_BY_BUTTON
if (digitalRead(0) == LOW) {
while (digitalRead(0) == LOW) ;
do_send(&sendjob);
}
#endif
}
With a Heltec ESP32 LoRa board, I’m getting “Packet queued” and then nothing happens, as shown in the following screenshot:
With an ESP32 Devkit V1 and an RF95 attached to it, I’m getting “FAILURE”, as shown in the screenshot below:
The failure seems to have something to do with the Arduino lmic library.
Interestingly, though maybe not relevant, I’m getting the same “FAILURE” message with the Heltec board if I select the “DOIT ESP32 DEVKIT V1” board under “Tools->Boards” in the Arduino IDE instead of the correct “Heltec WiFi LoRa 32”. The other way around, i.e. if I select the “Heltec WiFi LoRa 32” board in the Arduino IDE when actually programming the ESP32 DEVKIT V1 board, the failure persists.
Any help with this issue would be greatly appreciated!
