This little kit adds the special Zigbee powers to your SEGmeter, turning it into a wireless device!
What is this Zigbee you ask? It's a wireless mesh radio system, that allows SEGmeter to communicate using radio messages back to the SEGbox. It's really nice, and if you'd like to learn more about Zigbee, what it is and how it works go have a look here.
Think of Zigbee as a long serial cable for devices, and a special serial cable that can aggregate together multiple devices.
Check out our SEGmeter Zigbee Kit in the SEGshop
This means a couple of important things:
- More SEGmeters, measuring more circuits in more places (within radio range of course!)
- Connect Smart Plug mobile meters for individual appliances
- Measure other things, like temperature, light, water!
Ready set, check...
Check the kit contents, you should have:
- 1 x 3.3v 1A LM1117 voltage regulator
- 1 x 2.5mm 10uf tantalum capacitor (5v or higher)
- 2 x 10Kohm resistors
- 2 x 2.0mm 10pin female header sockets
If any of these aren't there, let us know!
You will need a Zigbee node, which is available in the SEGshop here
Let's get to it!
First up, we will mount the 3.3 volt voltage regulator. SEGmeter loves to run at 5 volts, which is good for many things it does, however Zigbee prefers the *other* voltage, so we need to make sure we adjust it's diet appropriately. We use the LM1117 volatage regulator that converts 5 into 3.3 at quite a good power current through put.
This little regulator is a very simple surface mount device, and it's a cinch to get right first time.
it goes here...
Now we know where the componentry is going to go, we need to prepare the surface mount pads for the voltage regulator, a couple of small blobs of solder is all that's needed for this important preparatory step.
dab, a teeny tiny amount of solder on.
Then when that's done it should look something like this!
four little blobs, all in a row
Next up, we break out the voltage regulator from it's little box, get our best and favorite pair tweezers (don't tell the wife of girlfriend!) and position the little voltage regulator.
position, position, position!
With one hand on the tweezers, the other on the soldering iron, and the SEGmeter board clamped to the table with in this case a little clippy clip, touch the hot iron on the long tab and let it settle in and cool, securing the regulator to the board.
and this little piggy went to market
With the base tab done, the regulator is now secure in it's new home. Next we need to affix the other three leggies. Care needs to be taken here to let the solder do the work as it's possible to destroy the regulator by cracking it's casing if too much pressure and heat is applied (don't ask me how I know that...)
let the solder do the talking
With the regulator affixed, it's time to install the 10k ohm resistors that help level shift the SEGmeter logic from 5V down to 3.3V for Zigbee's data consumption.
These little resistors go here, right next to the regulator. We install the regulator first, as this gives us a little more iron room to maneuver.
ten k was never so easy!
The 20 pin Digi Zigbee needs these special 2mm pitch headers. They go on now. To perform this stunt, i use what I affectionately term a FailBee - a Zigbee that no longer has any other use but to provide a template Zigbee to work with. If you don't have such a special Zigbee, it's possible to use blue-tack to fix the headers in place for attachement, or even a good Zigbee!
header up, rawhide!
Then I take my little special clippy clips, clamp the Zigbee on and get to work with the iron.
clamp it on
Now, with the Zigbee all clamped in place, I flip the board over and solder the headers on. With a good bead flow, this part of the assembly is really fun
If it's done to satisfaction levels one will have nice rounded beady blobs of solder holding the leggies of the headers in!
The next step is really REALLY IMPORTANT! (that's in capitals for a purpose too...).
For the 3.3 volt regulator to work properly, it needs to store a few electrons in a little tank, which in the electrical world is called a capacitor. We use a 10uF tantalum capacitor for this (made from coltan, a raw material of the Terminator's battle chassis, and it comes from the Congo, where people die for it...)
This capacitor is polarised, and it's not terribly clear from it's teeny tiny markings what's where. Just make sure you look for the little + and align it as so to prevent SEGmeter fail!
So we're done with our Zigbee kit installation, all that's needed is Zigbee and away you go.