19E042PIM v4 z1
Dependencies: 19E042PIM_MB_PINS
Diff: main.cpp
- Revision:
- 0:6380a1c94d6c
- Child:
- 1:c994530bdb3d
diff -r 000000000000 -r 6380a1c94d6c main.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/main.cpp Thu Nov 25 18:58:24 2021 +0000 @@ -0,0 +1,196 @@ +/* + * 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); + } +} \ No newline at end of file