Jimmy NSENGA / lora-group-project-2nd-master-cohort

This repo contains a code example of sending LoRa message that will be relayed by the Things Network to the ThingSpeak Channel of the project

main.cpp@0:490b5d248e91, 2020-11-22 (annotated)

Committer:
nsejim
Date:
Sun Nov 22 12:16:19 2020 +0000
Revision:
0:490b5d248e91
Code example of sending LoRa message to Things Network gateway and be relayed to the associated ThingSpeak channel

Who changed what in which revision?

UserRevisionLine numberNew contents of line
nsejim 0:490b5d248e91 1 #include "mbed.h" // Include the library of Mbed
nsejim 0:490b5d248e91 2 #include "LoRaWANInterface.h"
nsejim 0:490b5d248e91 3 #include "SX1276_LoRaRadio.h"
nsejim 0:490b5d248e91 4
nsejim 0:490b5d248e91 5
nsejim 0:490b5d248e91 6 /*
nsejim 0:490b5d248e91 7 Send LoRa message to a the group project Thingspeak channel
nsejim 0:490b5d248e91 8 https://thingspeak.com/channels/1234574/feed.json
nsejim 0:490b5d248e91 9 */
nsejim 0:490b5d248e91 10
nsejim 0:490b5d248e91 11 // The port we're sending and receiving on
nsejim 0:490b5d248e91 12 #define MBED_CONF_LORA_APP_PORT 1
nsejim 0:490b5d248e91 13
nsejim 0:490b5d248e91 14 InterruptIn send_data_button(p6);
nsejim 0:490b5d248e91 15
nsejim 0:490b5d248e91 16 // Device credentials, register device as OTAA in The Things Network and copy credentials here
nsejim 0:490b5d248e91 17 static uint8_t DEV_EUI[] = { 0x18, 0x11, 0x20, 0x20, 0x18, 0x11, 0x20, 0x20 };
nsejim 0:490b5d248e91 18 static uint8_t APP_EUI[] = { 0x70, 0xB3, 0xD5, 0x7E, 0xD0, 0x03, 0x84, 0x15 };
nsejim 0:490b5d248e91 19 static uint8_t APP_KEY[] = { 0x76, 0x8B, 0xD9, 0x68, 0xA9, 0x4C, 0xC0, 0xF6, 0x52, 0x20, 0x48, 0x7C, 0x00, 0xE6, 0x0D, 0x3C };
nsejim 0:490b5d248e91 20
nsejim 0:490b5d248e91 21
nsejim 0:490b5d248e91 22 // Peripherals (LoRa radio, temperature sensor and button)
nsejim 0:490b5d248e91 23 SX1276_LoRaRadio radio(D11, D12, D13, D10, A0, D2, D3, D4, D5, D8, D9, NC, NC, NC, NC, A4, NC, NC);
nsejim 0:490b5d248e91 24
nsejim 0:490b5d248e91 25 // EventQueue is required to dispatch events around
nsejim 0:490b5d248e91 26 static EventQueue ev_queue;
nsejim 0:490b5d248e91 27 // Constructing Mbed LoRaWANInterface and passing it down the radio object.
nsejim 0:490b5d248e91 28 static LoRaWANInterface lorawan(radio);
nsejim 0:490b5d248e91 29 // Application specific callbacks
nsejim 0:490b5d248e91 30 static lorawan_app_callbacks_t callbacks;
nsejim 0:490b5d248e91 31 // LoRaWAN stack event handler
nsejim 0:490b5d248e91 32 static void lora_event_handler(lorawan_event_t event);
nsejim 0:490b5d248e91 33
nsejim 0:490b5d248e91 34 // Send a message over LoRaWAN
nsejim 0:490b5d248e91 35 static void send_message(char *device, long int start, long int end, int topic) {
nsejim 0:490b5d248e91 36 uint8_t tx_buffer[50] = { 0 };
nsejim 0:490b5d248e91 37 // Sending strings over LoRaWAN is not recommended
nsejim 0:490b5d248e91 38 sprintf((char*) tx_buffer, "{\"device\":\"%s\",\"start\":%ld,\"end\":%ld,\"topic\":%d}", device, start, end, topic);
nsejim 0:490b5d248e91 39 int packet_len = strlen((char*) tx_buffer);
nsejim 0:490b5d248e91 40 printf("Sending %d bytes: \"%s\"\n", packet_len, tx_buffer);
nsejim 0:490b5d248e91 41 int16_t retcode = lorawan.send(MBED_CONF_LORA_APP_PORT, tx_buffer, packet_len, MSG_UNCONFIRMED_FLAG);
nsejim 0:490b5d248e91 42 // for some reason send() returns -1... I cannot find out why, the stack returns the right number. I feel that this is some weird Emscripten quirk
nsejim 0:490b5d248e91 43 if (retcode < 0) {
nsejim 0:490b5d248e91 44 retcode == LORAWAN_STATUS_WOULD_BLOCK ? printf("send - duty cycle violation\n")
nsejim 0:490b5d248e91 45 : printf("send() - Error code %d\n", retcode);
nsejim 0:490b5d248e91 46 return;
nsejim 0:490b5d248e91 47 }
nsejim 0:490b5d248e91 48 printf("%d bytes scheduled for transmission\n", retcode);
nsejim 0:490b5d248e91 49 }
nsejim 0:490b5d248e91 50
nsejim 0:490b5d248e91 51 int initialize_lora() {
nsejim 0:490b5d248e91 52 if (DEV_EUI[0] == 0x0 && DEV_EUI[1] == 0x0 && DEV_EUI[2] == 0x0 && DEV_EUI[3] == 0x0 && DEV_EUI[4] == 0x0 && DEV_EUI[5] == 0x0 && DEV_EUI[6] == 0x0 && DEV_EUI[7] == 0x0) {
nsejim 0:490b5d248e91 53 printf("Set your LoRaWAN credentials first!\n");
nsejim 0:490b5d248e91 54 return -1;
nsejim 0:490b5d248e91 55 }
nsejim 0:490b5d248e91 56 if (lorawan.initialize(&ev_queue) != LORAWAN_STATUS_OK) {
nsejim 0:490b5d248e91 57 printf("LoRa initialization failed!\n");
nsejim 0:490b5d248e91 58 return -1;
nsejim 0:490b5d248e91 59 }
nsejim 0:490b5d248e91 60 // prepare application callbacks
nsejim 0:490b5d248e91 61 callbacks.events = mbed::callback(lora_event_handler);
nsejim 0:490b5d248e91 62 lorawan.add_app_callbacks(&callbacks);
nsejim 0:490b5d248e91 63 // Disable adaptive data rating
nsejim 0:490b5d248e91 64 if (lorawan.disable_adaptive_datarate() != LORAWAN_STATUS_OK) {
nsejim 0:490b5d248e91 65 printf("disable_adaptive_datarate failed!\n");
nsejim 0:490b5d248e91 66 return -1;
nsejim 0:490b5d248e91 67 }
nsejim 0:490b5d248e91 68 lorawan.set_datarate(5); // SF7BW125
nsejim 0:490b5d248e91 69 lorawan_connect_t connect_params;
nsejim 0:490b5d248e91 70 connect_params.connect_type = LORAWAN_CONNECTION_OTAA;
nsejim 0:490b5d248e91 71 connect_params.connection_u.otaa.dev_eui = DEV_EUI;
nsejim 0:490b5d248e91 72 connect_params.connection_u.otaa.app_eui = APP_EUI;
nsejim 0:490b5d248e91 73 connect_params.connection_u.otaa.app_key = APP_KEY;
nsejim 0:490b5d248e91 74 connect_params.connection_u.otaa.nb_trials = 3;
nsejim 0:490b5d248e91 75
nsejim 0:490b5d248e91 76 lorawan_status_t retcode = lorawan.connect(connect_params);
nsejim 0:490b5d248e91 77
nsejim 0:490b5d248e91 78 if (retcode == LORAWAN_STATUS_OK ||
nsejim 0:490b5d248e91 79 retcode == LORAWAN_STATUS_CONNECT_IN_PROGRESS) {
nsejim 0:490b5d248e91 80 } else {
nsejim 0:490b5d248e91 81 printf("Connection error, code = %d\n", retcode);
nsejim 0:490b5d248e91 82 return -1;
nsejim 0:490b5d248e91 83 }
nsejim 0:490b5d248e91 84
nsejim 0:490b5d248e91 85 printf("LoRa Connection - In Progress ...\r\n");
nsejim 0:490b5d248e91 86 // make your event queue dispatching events forever
nsejim 0:490b5d248e91 87 ev_queue.dispatch_forever();
nsejim 0:490b5d248e91 88 return 0;
nsejim 0:490b5d248e91 89 }
nsejim 0:490b5d248e91 90
nsejim 0:490b5d248e91 91 void send_data_button_isr() {
nsejim 0:490b5d248e91 92
nsejim 0:490b5d248e91 93 char device[] = "MyDevice";
nsejim 0:490b5d248e91 94 int topic = 3; // topic identifier
nsejim 0:490b5d248e91 95 long int start = 1606037871; // start reading
nsejim 0:490b5d248e91 96 long int end = 1606038051; // end reading
nsejim 0:490b5d248e91 97
nsejim 0:490b5d248e91 98 send_message(device, start, end, topic);
nsejim 0:490b5d248e91 99 }
nsejim 0:490b5d248e91 100
nsejim 0:490b5d248e91 101 int main() {
nsejim 0:490b5d248e91 102 send_data_button.rise(ev_queue.event(&send_data_button_isr)); // Registering an ISR for button click
nsejim 0:490b5d248e91 103 initialize_lora();
nsejim 0:490b5d248e91 104 }
nsejim 0:490b5d248e91 105
nsejim 0:490b5d248e91 106 // Event handler
nsejim 0:490b5d248e91 107 static void lora_event_handler(lorawan_event_t event) {
nsejim 0:490b5d248e91 108 switch (event) {
nsejim 0:490b5d248e91 109 case CONNECTED:
nsejim 0:490b5d248e91 110 printf("LoRA Connection - Successful\n");
nsejim 0:490b5d248e91 111 break;
nsejim 0:490b5d248e91 112 case DISCONNECTED:
nsejim 0:490b5d248e91 113 ev_queue.break_dispatch();
nsejim 0:490b5d248e91 114 printf("LoRa Disconnected Successfully\n");
nsejim 0:490b5d248e91 115 break;
nsejim 0:490b5d248e91 116 case TX_DONE:
nsejim 0:490b5d248e91 117 printf("Message Sent to Network Server\n");
nsejim 0:490b5d248e91 118 break;
nsejim 0:490b5d248e91 119 case TX_TIMEOUT:
nsejim 0:490b5d248e91 120 case TX_ERROR:
nsejim 0:490b5d248e91 121 case TX_CRYPTO_ERROR:
nsejim 0:490b5d248e91 122 case TX_SCHEDULING_ERROR:
nsejim 0:490b5d248e91 123 printf("Transmission Error - EventCode = %d\n", event);
nsejim 0:490b5d248e91 124 break;
nsejim 0:490b5d248e91 125 case JOIN_FAILURE:
nsejim 0:490b5d248e91 126 printf("OTAA Failed - Check Keys\n");
nsejim 0:490b5d248e91 127 break;
nsejim 0:490b5d248e91 128 default:
nsejim 0:490b5d248e91 129 MBED_ASSERT("Unknown Event");
nsejim 0:490b5d248e91 130 }
nsejim 0:490b5d248e91 131 }
nsejim 0:490b5d248e91 132
nsejim 0:490b5d248e91 133