RaspberryPi/Web Server - Revision history

Admin at 18:40, 25 February 2017

2017-02-25T18:40:17Z

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	~~[[Category:Raspberry Pi]]~~
			=Flags=

			{{PiFlag}}

	[[Category:REST API]]		[[Category:REST API]]
	[[Category:Web]]		[[Category:Web]]
	[[Category:Python]]		[[Category:Python]]

Admin: /* Flask */

2017-02-25T18:39:49Z

Flask

← Older revision		Revision as of 18:39, 25 February 2017
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	For an example of how you might do this, see my Dymouse project on Github: http://github.com/charlesreid1/dymouse		For an example of how you might do this, see my Dymouse project on Github: http://github.com/charlesreid1/dymouse

	~~This uses~~ a ~~Raspberry and~~ a Flask ~~script~~ to ~~create an API for~~ a ~~USB postage scale~~. Python ~~provides a means for grabbing~~ the weight reading from the postage scale; Flask turns it into JSON~~; and~~ Javascript ~~turns~~ the JSON ~~into HTML text/plots~~.		The concept is to use a computer with a Flask server, with one side connected to a sensor, and the other side interacting with the user. Python libraries can be used to interface with USB devices (and get the weight reading from the postage scale). This information can be obtained by Flask, which turns it into JSON to be returned when the user requests it. This is linked to a REST-ful URL on the web server.

			On the user side, the user interacts with an HTML web page controlled by Javascript. It is the Javascript code that decides to make a JSON request to the REST-ful URL. It makes the request, based on user interaction or some other criteria, then parses the reading and adds it to the page in an appropriate manner.

Admin: /* Flask */

2017-02-25T18:36:02Z

Flask

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	[[Category:REST API]]		[[Category:REST API]]
	[[Category:Web]]		[[Category:Web]]

	[[Category:Python]]		[[Category:Python]]

Admin at 18:35, 25 February 2017

2017-02-25T18:35:01Z

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	[[Category:Raspberry Pi]]		[[Category:Raspberry Pi]]
	[[Category:Web ~~Server~~]]		[[Category:REST API]]
			[[Category:Web]]

	[[Category:Python]]		[[Category:Python]]

Admin at 23:47, 27 July 2015

2015-07-27T23:47:09Z

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	[[Category:~~RaspberryPi~~]]		[[Category:Raspberry Pi]]
			[[Category:Web Server]]
			[[Category:Python]]

Admin: Created page with "=Running Web Server on Raspberry Pi= If you're running a web server on Raspberry Pi, you'll probably want to run on port 80. However, Raspberry Pis sometimes have a problem w..."

2015-07-27T23:45:45Z

Created page with "=Running Web Server on Raspberry Pi= If you're running a web server on Raspberry Pi, you'll probably want to run on port 80. However, Raspberry Pis sometimes have a problem w..."

New page

=Running Web Server on Raspberry Pi=

If you're running a web server on Raspberry Pi, you'll probably want to run on port 80. However, Raspberry Pis sometimes have a problem when installing Python packages into <code>/usr/local/lib</code>, so you have to install them into a custom directory. This creates a problem when trying to import the package as root, because root python won't be able to find it (won't have the <code>$PYTHONPATH</code> variable set correctly).

To get around this, you can bind to port 80 without being root by following these instructions:

http://stackoverflow.com/questions/413807/is-there-a-way-for-non-root-processes-to-bind-to-privileged-ports-1024-on-l

http://www.wensley.org.uk/info#setpcaps

==Flask==

Flask is an excellent lightweight web server in Python. Flask makes it easy to create an API for requesting data and passing JSON between Python (which is a powerful language that can control all kinds of things on the Raspberry Pi) and Javascript (which provides a nice user front-end via a web interface).

For an example of how you might do this, see my Dymouse project on Github: http://github.com/charlesreid1/dymouse

This uses a Raspberry and a Flask script to create an API for a USB postage scale. Python provides a means for grabbing the weight reading from the postage scale; Flask turns it into JSON; and Javascript turns the JSON into HTML text/plots.

[[Category:RaspberryPi]]