![](/media/cache/profiles/olja.png.50x50_q85.png)
Student project, Faculty of Electrical Engineering, University of Belgrade
Dependencies: SSD1308_128x64_I2C Adafruit_GFX 19E042PIM_MB_PINS
main.cpp
- Committer:
- tzwell
- Date:
- 2021-11-25
- Revision:
- 0:6380a1c94d6c
- Child:
- 1:c994530bdb3d
File content as of revision 0:6380a1c94d6c:
/* * Program implements MQTT client on a NUCLEO-L476RG board * using arm mbed-mqtt library and ESP-WROOM-02 WiFi modem. * * University of Belgrade - School of Electrical Engineering * Department of Electronics * Bulevar Kralja Aleksandra 73, 11120 Belgrade, Serbia * * November 2021. * */ #include "mbed.h" #include "mb_pins.h" #include "platform/mbed_thread.h" #include "MQTTClientMbedOs.h" // LED2 blinking rate: #define BLINKING_RATE_MS 250 // Scaler to 3v3L #define VOLTAGE_SCALER 3.3f // Client yield timeout in miliseconds: #define YIELD_TIMEOUT_MS 1000 // Maximum number of networks to scan for: #define MAX_NETWORKS 15 // Small delay for network information printing: #define PRINTF_DELAY_MS 10 // Left potentiometer: AnalogIn pot1(MB_POT1); // Left button on the motherboard: InterruptIn sw1(MB_SW1); // Right LED on the motherboard: DigitalOut led2(MB_LED2); // WiFi network handler: WiFiInterface *wifi; // Creating TCP socket: TCPSocket socket; // Creating MQTT client using the TCP socket; MQTTClient client(&socket); // Message handler: MQTT::Message message; char* topic = "mbed-sample-pub"; char* topic_sub = "mbed-sample-sub"; // Counter of arrived messages: int arrivedcount = 0; // Flag indicating that button is not pressed: int button_pressed=0; // Returning a string for a provided network encryption: const char *sec2str(nsapi_security_t sec) { switch (sec) { case NSAPI_SECURITY_NONE: return "None"; case NSAPI_SECURITY_WEP: return "WEP"; case NSAPI_SECURITY_WPA: return "WPA"; case NSAPI_SECURITY_WPA2: return "WPA2"; case NSAPI_SECURITY_WPA_WPA2: return "WPA/WPA2"; case NSAPI_SECURITY_UNKNOWN: default: return "Unknown"; } } int scan_demo(WiFiInterface *wifi) { // Creating an access point WiFiAccessPoint *ap; printf("Scan:\n"); int count = wifi->scan(NULL,0); if (count <= 0) { printf("scan() failed with return value: %d\n", count); return 0; } // Limit number of network arbitrary to 15 count = count < MAX_NETWORKS ? count : MAX_NETWORKS; // Create a new object, array of WiFi APs, and assign it to ap variable: ap = new WiFiAccessPoint[count]; count = wifi->scan(ap, count); if (count <= 0) { printf("scan() failed with return value: %d\n", count); return 0; } // Print network information: for (int i = 0; i < count; i++) { printf("Network: %s secured: %s BSSID: %hhX:%hhX:%hhX:%hhx:%hhx:%hhx RSSI: %hhd Ch: %hhd\n", ap[i].get_ssid(), sec2str(ap[i].get_security()), ap[i].get_bssid()[0], ap[i].get_bssid()[1], ap[i].get_bssid()[2], ap[i].get_bssid()[3], ap[i].get_bssid()[4], ap[i].get_bssid()[5], ap[i].get_rssi(), ap[i].get_channel()); thread_sleep_for(PRINTF_DELAY_MS); } printf("%d networks available.\n", count); delete[] ap; return count; } void messageArrived(MQTT::MessageData& md) { MQTT::Message &message = md.message; //printf("Message arrived: qos %d, retained %d, dup %d, packetid %d\r\n", message.qos, message.retained, message.dup, message.id); printf("Message from the browser: %.*s\r\n", message.payloadlen, (char*)message.payload); ++arrivedcount; } void buttonFunction() { button_pressed=1; } int main() { sw1.fall(&buttonFunction); const char* hostname = "broker.hivemq.com"; int port = 1883; // Network interface wifi = WiFiInterface::get_default_instance(); if (!wifi) { printf("ERROR: No WiFiInterface found.\n"); return -1; } int count = scan_demo(wifi); if (count == 0) { printf("No WIFI APs found - can't continue further.\n"); return -1; } printf("\nConnecting to %s...\n", MBED_CONF_APP_WIFI_SSID); int ret = wifi->connect(MBED_CONF_APP_WIFI_SSID, MBED_CONF_APP_WIFI_PASSWORD, NSAPI_SECURITY_WPA_WPA2); if (ret != 0) { printf("\nConnection error: %d\n", ret); return -1; } printf("Success\n\n"); printf("MAC: %s\n", wifi->get_mac_address()); printf("IP: %s\n", wifi->get_ip_address()); printf("Netmask: %s\n", wifi->get_netmask()); printf("Gateway: %s\n", wifi->get_gateway()); printf("RSSI: %d\n\n", wifi->get_rssi()); socket.open(wifi); socket.connect(hostname, port); MQTTPacket_connectData data = MQTTPacket_connectData_initializer; data.MQTTVersion = 3; data.clientID.cstring = "NUCLEO-L476RG-60"; int rc=0; if ((rc = client.connect(data)) != 0) printf("rc from MQTT connect is %d\r\n", rc); if ((rc = client.subscribe(topic_sub, MQTT::QOS2, messageArrived)) != 0) printf("rc from MQTT subscribe is %d\r\n", rc); while (true) { // Show that the loop is running by switching motherboard LED2: led2 = !led2; thread_sleep_for(BLINKING_RATE_MS); if (button_pressed==1) { button_pressed=0; // QoS 0 char buf[100]; sprintf(buf, "V(POT1) = %1.2f\r\n", pot1*VOLTAGE_SCALER); message.qos = MQTT::QOS0; message.retained = false; message.dup = false; message.payload = (void*)buf; message.payloadlen = strlen(buf)+1; client.publish(topic, message); } // Need to call yield API to maintain connection: client.yield(YIELD_TIMEOUT_MS); } }