Easy Web Interface With GPIO Access Runs On Raspberry Pi

Here’s a Raspberry Pi hack that adds web control using PHP and MySQL. As you can see in the image, it serves up a webpage (using the Apache2 server) which allows you to change the state of the GPIO pins. It’s not super-complicated, but it is nice to see a step-by-step guide for installing and configuring the package.

Web interface GPIO control is one of the features we loved about the Adafruit Web IDE. But this offering is loaded completely from the RPi (the Adafruit package uses cloud based code) and utilizes the tools most Linux network admins will be used to. A MySQL database manages the connection between GUI commands and GPIO modification. The webpage is served up by a PHP script which takes care of polling and changing database values. Configuration requires a new database, plus the username and password which has access to it.

Raspberry Pi Used To Automate A Dimmable Light Bulb

raspberry-pi-controlled-dimmer

[Stephen] took the safe route when getting his Raspberry Pi to dim an AC light bulb. He didn’t roll his own outlet box with a mains-rated relay inside, going with a mechanical connection instead of electrical. By attaching a servo motor to the dimmer knob the RPi can adjust the light level without risk of electric shock.

He is using the ServoBlaster package to drive the servo motor with the Raspberry Pi GPIO pins. That’s all fine and good by itself, but he went the extra mile and designed a few different levels of functionality around the pairing. The motivation behind the hack was to build a sunrise clock that had a lot of power when it comes to luminosity. But he also plied the RPi’s networking features to serve up a web-based control. It has a slider to set the light level, as well as breath (like a slow fade) and flash features.

The servo is a bit noisy when moving quickly, but the sunrise alarm takes 30 minutes so the gears don’t really make any noise at all. Check it out in the clip after the break.

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3D Printer Control For The Raspi

Instead of dedicating his laptop to control his RepRap all night, [Walter] is using a Raspberry Pi as an Internet-enabled front end for his 3D printer.

Before [Walter] got his hands on a Raspberry Pi, he set up his laptop next to his RepRap and let the machine do its work for hours on end. Obviously, this tied up his laptop for a while so when his Raspi was delivered he was eager to offload the responsibilities of controlling a printer to his new Linux board.

Right now, [Walter] has his Raspberry Pi set up as a web interface able to control his printer similar to Pronterface. We have to note that the Raspberry Pi isn’t driving servos or feeding filament onto the bed; those responsibilities are still handled by the RepRap electronics, but the ability to use a 3D printer over the web is still pretty cool.

[Walter] is putting the finishing touches on his 3D printer web interface, after which he’ll upload everything onto the git. Planned features for future updates include uploading gcode from the web and an option to connect a webcam for visual feedback when controlling a remote printer.

Video demo after the break.

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