# A rather simple WiFi temperature sender

Use a micro-controller with WiFi, e.g. a NodeMCU V2 or V3, to send temperature values read from a DS18B20 sensor to a server.

## Concept

* The sender is a controller with WiFi that can read values from a temperature
sensor.
* Values are sent to a server with hard-coded IP address.
* The controller is configured to go to "deep sleep" after sending values.
* The wakeup feature of the controller shall be used to reactivate it after
about 30 min. Note that not all controller boards have such a feature,
e.g. the very simple ESP-01 boards to not make the wakeup pin accessible.
* Using deep sleep, it should be possible to run the sender for several days
or even weeks with a simple USB power bank.<br/>
Of course, a more sophisticated powering system would be nice.
* The messages are a simple UDP packet containing a JSON structure.
* The server listens at a pre-configured port and can process the
JSON structure.
* One server implementation is a Python script that collects the reported
values in a CSV file.
* The CSV file can be processed into a simple static web page for display in
the local network.

**WORK IN PROGRESS**