SafeDuino – Part 04: Further Afield – A Complete Redesign?

After having not had much time to work on this project in the past few months, with a major half-million dollar project going on at one of my clients, which was/is the implantation of a new computer system of my own design that will be serving them for the next 20 years or more (well the physical infrastructure will be, the PC’s wireless, network, servers etc won’t they are replaced on a 3 year cycle, again on my insistence) and with one of the suppliers delivering critical components in excess of week late it has pushed back the final deployment for a couple of months as now I can only do core works on weekends and after hours, I have not had much time for this project.

What I have been doing/contemplating is two things however, firstly is whether I need an LCD screen/buttons interface, and I have decided that I do need one, this has become evident so that I can set up the system “in place” when it is finally deployed.

The other thing I want to do is be able to deploy some sensors and control circuits remotely, including some in hard to access places, well ones that once they are in they will not be easily accessible. To this end I have come up with the idea of using network cable for limited power (5VDC for system power) and command and control signals, and where required I will use Flat-Flex Cables’ (FFC’s)  to get into those tight spots that I cannot otherwise support sensors in. 

 What this leaves me with is a system that is essentially divided into three distinct parts, the main controller (the Freeduino EtherMega) the distribution node which is connected to the EtherMega via network cable, and the sensors and control points are connected to the distribution nodes via CAT3 (telephone) cabling or via FFC’s (which are limited to 18″) where required.

This now leaves me of working out how to select which pins go to which distribution point via the network cabling, this I am still trying to solve, however jumper wires are looking like the best option at this point

SafeDuino – Part 02: (Partial) Parts test

I have now got some of the equipment for my SafeDuino, as has been mentioned previously I have selected Freetronics for much of my kit for this, sure I could make most of it manually, but I do prefer it being on a circuit board to make it that bit easier to mount.

So far I have obtained the following from a local Jaycar store

  • Freetronics EtherMega
  • RGB LED, This may yet be changed, as something I would like to do would be easier if I just had the RGB LED itself without the board, well rather easier without the IC on it, the board is prefered however.
  • Humidity sensor, Freetronics board mounted, however it is a “common” DHT22
  • Reed Switch, this came from my stash of components, but was originally from Jaycar as well
  • 2000 Ohm and 8000 Ohm resistors to make a voltage divider
  • NDriver Transitor relay, this is to allow me to turn on/off the LED light strip

Good news is all parts have so far passed testing, now its just a matter of waiting for the rest of the items to arive, in the mean time however I will not be slacking I will be using a simulator  (Simulator for Arduino from Virtronics) and the components already at hand to start work on this project.

Whats worse is I have already decided on my next project, several (as we have several locations on the property that require it) water tank level sensors, based upon the Freetronics EtherTen, this one has been chosen for that project as I can use the Cisco POE switches I have at home to power it from the network, meaning no external power requirements