https://vimeo.com/87249046 So what did I build? My servers <-> Internet <-> Rapsberry Pi <-> Arduino <-> Shiftregister <-> blinking things Cronjob running a Ruby script This script does: Load list of ips and loop through list doing: Ping ip Try to login via ssh (key based) Check if other sessions are open Check if logfiles should be checked (logwatch report with bad words) Save short status to byte array Write this array to the EEPROM (512 bytes!!) of the Arduino (serial) Loop within Arduino Load array of status bits Loop through array For each item Increase counter and refresh digit display (count + 1) Check status of each byte Enable or disable LEDs So the digit display is showing which server status is currently displayed (0 to 9 - so 10 servers). The 6 LEDs (red/green/red/green/yellow/yellow) do show: Ping status (red bad / green good) Service status (red bad / green good) [if every required service is running or not] Other sessions are open (yellow) [so someone is playing around] Logstatus (yellow) [Hey I should look at those log files] I am still searching for a good 16 bit shift register (maybe the STP16C596A) and I want to add a 4x16 LCD module too. The Raspberry Pi is able to handle the stuff too but can only work with 3.3V input/output where the Arduino can handle 5V input/output. It is a pain to work with resistors for each single GPIO of the Raspberry Pi: And - of course - you save a lot of energy because the Arduino is more energy efficient. I like the idea of separated areas of responsibility: Raspberry Pi doing all the network and analysing stuff and Arduino doing all the electro-technics. I toy with the idea of buying a USB hub to connect several Arduinos with one Raspberry Pi. One Arduino for the LCD/LED stuff One Arduino for the temperature/light/movement stuff One Arduino for a touch button pad - each button for one action like ssh login and calling scripts, etc. Yup your right - I am currently running riot on this electro stuff. Edit: Added video link.