Help with Arduino and Raspbeery Pi connection

[Adeering]

Looking to upgrade my system to a more graphical interface. As the arduino isnt the greatest for graphics I was thinking to using the Raspberry Pi as an interface to the arduino. However havent dealt with linux much so not sure exactly where to get started on this. Have a couple questions:

1. Whats the best way to do the interface? Was thinking a local server hosting a webpage that I can access on my tablet.

2. How to talk between the raspberry pi and arduino?

Any help or examples would be great. Thanks

 

[HornetSparky]

Recommend TeensyPi website. Teensy is close to Arduino and should get you started on how to get the two talking. Www.teensypi.com. And the proprietor of said website is a home brewer on this forum.

 

[alien]

The teensypi is a great project.

Another option is the BeagleBone black, which has as more input/output pins than the Pi for about the same price.

 

[goingmad]

I'm not aware on your current build setup, so these are just my two cents...

1. Setting up a web server on RPI is just matter of seconds, I'd suggest you to go with a light web server, such as lighttpd. Here is an easy example to follow. You can then access it with your device, whatever it is, it just needs to be in the same network.

2. Here you have to stop a bit, thinking about the best option for your system. RPI and Arduino have one ethernet port each. If you want to connect each other through a Lan cable, your ethernet ports have gone. But you obviously need to have your RPI reachable also from other device in the network - i.e. your tablet - so you should add a usb wifi dongle to it, in order to connect your network to RPI. Another way to follow should be to access the Arduino from the usb port, different path, maybe more complicated, but usable. Not to mention you could also connect the two devices to a small Hub, connecting it to the network. If you take a look at the brewtroller project you could find some useful info, it's basically an Arduino with additional useful stuffs embedded and optimised for the brewing process.

 

[kwadric]

I use a Rpi and Arduino in my fermentation control system. I use an Arduino to take temp readings and turn the 120V relays on and off. I have the serial pins on the Arduino connected to the Rpi's GPIO serial pins for serial communication. On the Rpi I use a Python script to read and write to Arduino. The same Python script logs temp data into a mySQL database. I store the set points in the same db. I also have a websever on the Rpi. I use php webpages for the user interface. I use the full LAMP server on the Rpi. It is drastic over kill, but the Rpi has the room and the install was easy.

In a lot of ways, my fermentation system is overly complicated. For my electric brewing rig I just connect a Arduino to a laptop with a USB cable and run a visual basic program for the user interface. This works great for a few hours on brew day, but the USB to serial conversion is not stable enough for over multiple weeks for fermentation control. That is why I avoid the serial to USB conversion. You results may vary.