Arduino used in home automation projects? It seems that the only limit is imagination. But actually there’s some limiting introduced by the Arduino hardware itself; original Arduino boards were designed as a lab tool rather than a module to be embedded in home automation controllers. Even so, many makers use Arduino boards in such projects, sometimes creating nice and safe projects, and many other times creating totally unsafe and dangerous projects. But does it has to be that way? I don’t think so…
Some clever manufactures have caught the idea of making ruggedized versions of the original Arduino, focused towards small scale automation projects.
On of those manufacturers is Controllino, based in Innsbruck, Austria. In their offer we have three Arduino compatible, DIN-rail mountable controllers. These small controllers have from 8 up to 21 inputs, 6 to 16 outputs and a range of peripherals from RTC to SPI, I2C, RS-485 and Ethernet.
Today I have on my workbench one Controllino Mini, the smallest in the Controllino range, which I plan to use as a smart controller for a water pump. But before that, let’s take a look at what the Controllino Mini can do…
In the box we will find only the Controllino. Datasheet, pinouts and Arduino plugin installer have to be downloaded from the http://controllino.biz/downloads/ website (note: the initial controllino.cc domain is not working anymore, it returns an 403 error message).
Right out of the box you can feel the Controllino Mini is not a toy. It has a sturdy look, a nice finishing, well marked connectors.
On the top of the Controllino Mini we find a set of 20 LEDs, the reset button, USB connector used for programming, a button that enables or disables the RTC and a 26-pin connector that can be used to directly interface to microcontroller pins. All signal pins on this connector are protected with serial resistance. Pins that provide 5V and 3.3V are also present, with a total current limit of 200mA (150mA for the 3.3V pin). .
As inputs we find a number of six analog/digital input connectors plus two digital connectors which can be configured as external interrupt sources. The datasheet says all those pins have an automatic divider, with the division ratio of 3.06 for 12V supply and 6.14 for 24V supply.