Note This is a web-version of a tutorial chapter embedded right into the XOD IDE. To get a better learning experience we recommend to install the desktop IDE or start the browser-based IDE, and you’ll see the same tutorial there.

Internet Tethering

Screenshot of 014-internet-tethering

There is a large class of applications known as IoT (Internet of Things) when the hardware connects to the Internet to send or receive data from some server. For example, log the temperature and moisture for smart greenhouses, get the current time, weather, send third-party service API request, and so on.

In this chapter, we are going to fetch the current date/time from the XOD Cloud API.

The xod-cloud/basics/now node sends a request to the XOD Cloud, parses the response, and outputs it as a datetime type value.

This node has an input pin INET. This pin has to be connected to an internet provider. The Internet can be provided:

  • by the controller board (such as ESP8266)
  • by an extension module (such as W5500 Ethernet Shield)
  • by your PC. This trick is known as Internet tethering and works in simulation and debug modes

Note, we’ve placed a select node here to get a reasonable value until we receive the result from the cloud. Otherwise, we would get a default datetime value, which is equal to 1970-01-01 00:00:00, and it might be confusing.

Excercise #

Update the current datetime value by sending pulses.

  1. Place a tweak-pulse node.
  2. Link it to the INIT pin
  3. To make a value in the watch node properly, you need to provide the third possible value "Waiting pulse". Drag the handle of the select node to the right to add one more pair of input pins
  4. Bind "Waiting pulse" and “On Boot” to the latest pair of pins.
  5. Link tweak-pulse to the S2 pin
  6. Simulate the patch and send pulse using the tweak-pulse node.
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