ThingsBoard and Mbed IoT application for STM32 B-L475E-IOT01A board, article: https://forgge.github.io/B-L475E-IOT01A-thingsboard-read-temperature-and-humidity-using-mbed.html

main.cpp

// main.cpp

#include "mbed.h"
#include "ISM43362Interface.h"
#include "TCPSocket.h"
#include "MQTTmbed.h"
#include "MQTTClient.h"
#include "HTS221Sensor.h"

// Definitions ---------------------------------------------------------

// Change it with your WiFi network name
#define WIFI_NETWORK_NAME       "<YOUR_WIFI_NETWORK_HERE>"
// Change it with your WiFi password name
#define WIFI_NETWORK_PASSWORD   "<YOUR_WIFI_NETWORK_PASSWORD_HERE>"
#define WIFI_SECURITY           NSAPI_SECURITY_WPA_WPA2

#define MQTT_HOST               "demo.thingsboard.io"
#define MQTT_PORT               1883
#define MQTT_TOPIC              "v1/devices/me/telemetry"

// Network adapter for Paho MQTT library -------------------------------

class MQTTNetwork
{
public:
    MQTTNetwork(NetworkInterface* aNetwork) : network(aNetwork) {
        socket = new TCPSocket();
    }

    ~MQTTNetwork() {
        delete socket;
    }

    int read(unsigned char* buffer, int len, int timeout) {
        return socket->recv(buffer, len);
    }

    int write(unsigned char* buffer, int len, int timeout) {
        return socket->send(buffer, len);
    }

    int connect(const char* hostname, int port) {
        socket->open(network);
        return socket->connect(hostname, port);
    }

    int disconnect() {
        return socket->close();
    }

private:
    NetworkInterface* network;
    TCPSocket* socket;
};

int main()
{
    int count = 0;

    ISM43362Interface wifi(MBED_CONF_APP_WIFI_SPI_MOSI,
            MBED_CONF_APP_WIFI_SPI_MISO,
            MBED_CONF_APP_WIFI_SPI_SCLK,
            MBED_CONF_APP_WIFI_SPI_NSS,
            MBED_CONF_APP_WIFI_RESET,
            MBED_CONF_APP_WIFI_DATAREADY,
            MBED_CONF_APP_WIFI_WAKEUP, false);

    // Scanning WiFi networks ------------------------------------------

    WiFiAccessPoint *ap;

    count = wifi.scan(NULL, 0);
    printf("%d networks available.\n", count);

    /* Limit number of network arbitrary to 15 */
    count = count < 15 ? count : 15;

    ap = new WiFiAccessPoint[count];
    count = wifi.scan(ap, count);
    for (int i = 0; i < count; i++) {
        printf("Network: %s RSSI: %hhd\n", ap[i].get_ssid(), ap[i].get_rssi());
    }

    delete[] ap;

    // Connecting to WiFi network --------------------------------------

    printf("\nConnecting to %s...\n", WIFI_NETWORK_NAME);
    int ret = wifi.connect(WIFI_NETWORK_NAME, WIFI_NETWORK_PASSWORD, WIFI_SECURITY);
    if (ret != 0) {
        printf("\nConnection error\n");
        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());

    // Connect to ThingsBoard ----------------------------------------------

    MQTTNetwork network(&wifi);
    MQTT::Client<MQTTNetwork, Countdown> client(network);

    char assess_token[] = "<YOUR_ACCESS_TOKEN_HERE>";

    MQTTPacket_connectData conn_data = MQTTPacket_connectData_initializer;
    conn_data.username.cstring = assess_token;

    if (network.connect(MQTT_HOST, MQTT_PORT) < 0) {
        printf("failed to connect to " MQTT_HOST  "\n");
        return -1;
    }

    if (client.connect(conn_data) < 0) {
        printf("failed to send MQTT connect message\n");
        return -1;
    }

    printf("successfully connect!\n\n");
    
    // Initialize sensors --------------------------------------------------

    uint8_t id;
    DevI2C i2c_2(PB_11, PB_10);
    HTS221Sensor hum_temp(&i2c_2);

    hum_temp.init(NULL);
    hum_temp.enable();
    hum_temp.read_id(&id);
    printf("HTS221  humidity & temperature sensor = 0x%X\r\n", id);

    // Get data from sensors -----------------------------------------------

    for (;;) {
        float temp, humid;

        hum_temp.get_temperature(&temp);
        hum_temp.get_humidity(&humid);
        printf("HTS221:  [temp] %.2f C, [hum]   %.2f%%\r\n", temp, humid);

        char msg[256];
        int n = snprintf(msg, sizeof(msg), 
            "{\"temperature\":%f, \"humidity\":%f, \"active\": false}",
            temp, humid);

        void *payload = reinterpret_cast<void*>(msg);
        size_t payload_len = n;

        printf("publish to: %s %d %s\r\n", MQTT_HOST, MQTT_PORT, MQTT_TOPIC);

        if (client.publish(MQTT_TOPIC, payload, n) < 0) {
            printf("failed to publish MQTT message");
        }

        wait_ms(5000);
    }

    // Shouldn't get there, but let's leave it anyway --------------------------------------------------------------------------

    client.disconnect();
    wifi.disconnect();

    printf("\ndone\n");
    return 0;
}

mbed_app.json

{
    "macros": [
        "MBED_CONF_APP_MAIN_STACK_SIZE=6000",
        "MBED_CONF_APP_THREAD_STACK_SIZE=6000",
        "DEVICE_STDIO_MESSAGES=1"
    ],
    "config": {
        "wifi-shield": {
            "help": "Options are internal, WIFI_IDW0XX1",
            "value": "internal"
        },
        "wifi-tx": {
            "help": "TX pin for serial connection to external device",
            "value": "D1"
        },
        "wifi-rx": {
            "help": "RX pin for serial connection to external device",
            "value": "D0"
        },
        "wifi-spi_miso": {
            "help": "SPI-MISO connection to external device",
            "value": "PC_11"
        },
        "wifi-spi_mosi": {
            "help": "SPI-MOSI connection to external device",
            "value": "PC_12"
        },
        "wifi-spi_sclk": {
            "help": "SPI-CLOCK connection to external device",
            "value": "PC_10"
        },
        "wifi-spi_nss": {
            "help": "SPI chip select of external device",
            "value": "PE_0"
        },
        "wifi-reset": {
            "help": "WIFI module reset pin",
            "value": "PE_8"
        },
        "wifi-dataready": {
            "help": "WIFI module data ready pin",
            "value": "PE_1"
        },
        "wifi-wakeup": {
            "help": "WIFI module wakeup pin",
            "value": "PB_12"
        }
    },
    "target_overrides": {
        "*": {
            "platform.stdio-baud-rate": 115200,
            "platform.stdio-convert-newlines": true
        },
        "DISCO_L475VG_IOT1A": {
            "wifi-spi_miso": "PC_11",
            "wifi-spi_mosi": "PC_12",
            "wifi-spi_sclk": "PC_10",
            "wifi-spi_nss": "PE_0",
            "wifi-reset": "PE_8",
            "wifi-dataready": "PE_1",
            "wifi-wakeup": "PB_12"
        }
    }
}

stm32_iot_kit_dashboard.json

{
  "title": "STM32 IoT Kit dashboard",
  "configuration": {
    "widgets": {
      "bf33af9b-f840-0440-f258-bce055fff304": {
        "isSystemType": true,
        "bundleAlias": "charts",
        "typeAlias": "basic_timeseries",
        "type": "timeseries",
        "title": "New widget",
        "sizeX": 8,
        "sizeY": 5,
        "config": {
          "datasources": [
            {
              "type": "entity",
              "dataKeys": [
                {
                  "name": "humidity",
                  "type": "timeseries",
                  "label": "humidity",
                  "color": "#2196f3",
                  "settings": {
                    "showLines": true,
                    "fillLines": false,
                    "showPoints": false,
                    "tooltipValueFormatter": "",
                    "showSeparateAxis": false,
                    "axisTitle": "",
                    "axisTickDecimals": 0,
                    "axisPosition": "left",
                    "axisTicksFormatter": ""
                  },
                  "_hash": 0.01464221283315692
                },
                {
                  "name": "temperature",
                  "type": "timeseries",
                  "label": "temperature",
                  "color": "#4caf50",
                  "settings": {
                    "showLines": true,
                    "fillLines": false,
                    "showPoints": false,
                    "tooltipValueFormatter": "",
                    "showSeparateAxis": false,
                    "axisTitle": "",
                    "axisTickDecimals": 0,
                    "axisPosition": "left",
                    "axisTicksFormatter": ""
                  },
                  "_hash": 0.8201548016278053
                }
              ],
              "entityAliasId": "21829d87-db1c-508f-c295-e1902a56d4bb"
            }
          ],
          "timewindow": {
            "realtime": {
              "timewindowMs": 60000
            }
          },
          "showTitle": true,
          "backgroundColor": "#fff",
          "color": "rgba(0, 0, 0, 0.87)",
          "padding": "8px",
          "settings": {
            "shadowSize": 4,
            "fontColor": "#545454",
            "fontSize": 10,
            "xaxis": {
              "showLabels": true,
              "color": "#545454"
            },
            "yaxis": {
              "showLabels": true,
              "color": "#545454"
            },
            "grid": {
              "color": "#545454",
              "tickColor": "#DDDDDD",
              "verticalLines": true,
              "horizontalLines": true,
              "outlineWidth": 1
            },
            "stack": false,
            "tooltipIndividual": false
          },
          "title": "New Timeseries - Flot",
          "dropShadow": true,
          "enableFullscreen": true,
          "titleStyle": {
            "fontSize": "16px",
            "fontWeight": 400
          },
          "mobileHeight": null,
          "widgetStyle": {},
          "useDashboardTimewindow": true,
          "showLegend": true,
          "actions": {}
        },
        "id": "bf33af9b-f840-0440-f258-bce055fff304"
      }
    },
    "states": {
      "default": {
        "name": "STM32 IoT Kit dashboard",
        "root": true,
        "layouts": {
          "main": {
            "widgets": {
              "bf33af9b-f840-0440-f258-bce055fff304": {
                "sizeX": 8,
                "sizeY": 5,
                "mobileHeight": null,
                "row": 0,
                "col": 0
              }
            },
            "gridSettings": {
              "backgroundColor": "#eeeeee",
              "color": "rgba(0,0,0,0.870588)",
              "columns": 24,
              "margins": [
                10,
                10
              ],
              "backgroundSizeMode": "100%"
            }
          }
        }
      }
    },
    "entityAliases": {
      "21829d87-db1c-508f-c295-e1902a56d4bb": {
        "id": "21829d87-db1c-508f-c295-e1902a56d4bb",
        "alias": "IoT Kit alias",
        "filter": {
          "type": "singleEntity",
          "resolveMultiple": false,
          "singleEntity": {
            "entityType": "DEVICE",
            "id": "217e62b0-3dc6-11e8-82d4-c3b186e30863"
          }
        }
      }
    },
    "timewindow": {
      "displayValue": "",
      "selectedTab": 0,
      "realtime": {
        "interval": 1000,
        "timewindowMs": 60000
      },
      "history": {
        "historyType": 0,
        "interval": 1000,
        "timewindowMs": 60000,
        "fixedTimewindow": {
          "startTimeMs": 1523774931204,
          "endTimeMs": 1523861331204
        }
      },
      "aggregation": {
        "type": "AVG",
        "limit": 200
      }
    },
    "settings": {
      "stateControllerId": "entity",
      "showTitle": false,
      "showDashboardsSelect": true,
      "showEntitiesSelect": true,
      "showDashboardTimewindow": true,
      "showDashboardExport": true,
      "toolbarAlwaysOpen": true
    }
  },
  "name": "STM32 IoT Kit dashboard"
}