Here is an example of a module that takes 4 analog inputs and 4 digital inputs, encodes the data in JSON and streams it to a server via TCP with REST compatibility.
In this specific example the module is taking data from 3 MQ type gas sensors, MQ2, MQ8 and MQ135 and temperature and humidity values from a DHT22 sensor.
The input from the analog gas sensors can be calibrated via independent trimmers.
SSID, Password of the wifi network, Server and Port and Heartbeat can be configured via a web command, with no need of using the serial port.
An LED indicates when the board obtained an IP address.