Program Flow

Overview:
The whole application is event driven.
At bootup, two timers are started. One ticking every second and the other every 15s.
The timer ticking every 1 second, checks and maintains the network connectivity.
Timer ticking every 15 second, pushes the data to the cloud.
Steps:
Step 1: Connect to WiFi.
For this, the esp32 starts and AP (ssid=powersense, password=password). Connect to the AP and Sign In to the network. Give the WIFI credentials and done.
Step 2: Connect to MQTT.
After WiFi is successfully connected, the device connects to the nodesense.baseapp.com through MQTT.
Step 3: Poll ATM90E26 every 15s via SPI and get the data.
The readings are pushed to nodesense.baseapp.com.