Third-world countries have better internet then me!

We moved into a brand new home about 3 months ago. Most people would have checked out the comms infrastructure in the area prior to buying. Silly me however assumed that being only 20km from the center of Perth city we would be able to achieve decent DSL speeds. Well… I can tell you that no matter how close you are to the city, it is always wise to check out the telephone exchange in your suburb. After moving in and being sold “ADSL2+” we were very disappointed with the speeds and began looking for alternatives. This is my journey…


"ADSL2+"

After moving in I contacted our Telecom company as you do, and requested ADSL2+ be installed. After a few days sure enough we had been setup with ADSL2+ and a 1000Gb Monthly data plan. I was pretty excited that the service had been setup so quickly, however the joy was short lived after I ran a speedtest… 1.6Mbps … consistently.

To keep the story short, I went back and forward with the telecom company tech support to see if it was a fault or just the standard. As it turns out they could not offer any better speeds into my residence. The company ended up refunding everything because it was not even possible to use the data in a month with speeds like that.

We all have “that mate” who boasts about his internet speed, and it just so happens my mate has up to 100Mbps and is only 900m away. (Yes….devastating I know…). So I hit him up to see if we could pipe some traffic over to mine. But first I needed to see if we had “Line of sight” (LOS) between the two houses. This is what we had to work with.

~900m shot, one house elevated above the other, a few parks in the way. Easy you say! well….it seems the trees are the limiting factor here. We have large pockets of trees in the way.

What I will say about the Airgrids though is that they are super simple to assemble. (Tool-Less design) and really fast to get up and running. With the Airgrid having the radio inside the feed-horn, all you require is a piece of cat5 and the POE injector and your in business. I foresee the Airgrids being used in rural environments with direct LOS to the target. I would probably look elsewhere if I was trying to push further then 10-15km though.


5Ghz (Make note to self: 5Ghz does not like trees!)

My first attempt at setting up the link failed miserably. Now 5Ghz obviously gives us the most throughput. But with the gear I had, I was unable to even achieve a link.

I purchased the Airgrids for an economical $99ea. Hopeful I may achieve even half the 80Mbps suggest on the ubiquiti planner. The Airgrids are a single channel radio operating in the 5Ghz unlicensed band. For the price and output they appeared to be a good bet. Me being a bit of a novice though didn’t take into account the “tree” effect on 5Ghz. It seems that there is a substantial difference in punching power between 5Ghz and say 900Mhz. (Which I ended up with!)


2.4Ghz (Success - But only just! Not our final solution)

Since 5Ghz for me was a total failure, I decided to give 2.4Ghz Unlicensed a crack. The first thing I want to say is that I did not use rockets with rocket-dish antennas. Everyone has told me, “you would be surprised how much better the good gear works” and I agree, however with a $1200+ outlay I decided to try single channel radios first. I could get my hands on some Ubiquti bullets and some cheap 28dBi grid antennas to test the link first.

I did have initial success getting the links up and running, however no matter what I did I was unable to improve the signal strength. I tried to get as much elevation as I could on each roof mount, I tried lowering the channel widths etc etc. At times I would get a solid 5Mbps of internet traffic but most of the time I would equal my 1.6Mbps that I had with DSL.

Maybe I could double the throughput with Ubiquti MIMO Rockets and dishes, but I was still weary to spend money on the gear only to experience the same “flutter” that I was on single channel gear.


900Mhz (Winner Winner! For this link anyways.)

A mate of mine suggested I give 900Mhz radios a go to see how that went. I was starting to see that as we stepped down the frequency range the “punching” power through the trees was indeed getting better. However using the 900Mhz band in Australia is a little bit tricky and you have to be careful with your setup so that you do not break the law. From what I can tell, 922Mhz is the only frequency you are allowed to use and can use up to 10Mhz channel width on this frequency. Thus the throughput is lowered significantly. However If I can still achieve 20Mbps of actual throughput then I’m still winning.

The other consideration is the power levels. You really need to drop the power (Most 900Mhz Ubiquti radios that come out of Australia are limited by firmware so you cannot push the limits anyhow.) From what I can tell some of the 3G mobile services sit on the 900Mhz range and the ACMA does not want unlicensed users to interfere. Which makes sense.

With all that in mind, if you have another radio sitting on 900Mhz close by you could be in trouble because you cannot move from 922Mhz.

So our initial testing saw us setup 2 x 900 Rockets with the MIMO 16dBi Yagi. We had it sitting on the roof and it already had a link. Not very good but was in. Once we got it up the mast and semi aligned we could see straight away that a lot of the “flutter” had disappeared and the signal strength was sitting solid. A quick speed test saw us get a solid 10mbps on a 5Mhz channel width. This put a smile on my face.


PiFrame - Surfboard

The idea behind this was to create an aesthetically pleasing frame for an old screen that I had lying around. No chance was I going to create a standard boring square frame and hang this on the wall. It has been done before…. A few weeks prior to making the surfboard frame I had seen a really nice piece of static wall art with a massive photo framed into a board. It looked unreal and was the inspiration for this surfboard PiFrame.


Parts List

  • Suitable wooden panel approx 18-20mm thick. (I used 1800x600 Panel, 18mm thick)
  • An old LCD monitor (Preferably with buttons including power on the bottom or back. not on the front.)
  • A Solid wall mount (I used a small VESA mount extendable arm - yes it holds the weight fine....)
  • RPI2 with Raspbian installed.
  • 5v PSU - (I used good quality Meanwell enclosed PSU)
  • HDMI cable
  • USB wifi module
  • 240v IEC cable - Y cable with two inputs.


The Frame

For the Initial board I decided to use the workshop CNC router to speed up the process. The first thing we did was decide upon the shape for the board. The classic thruster shape seemed like the best choice as we could scale it down to fit the 1800×600 wooden panel easily. After drawing up the basic board shape in solid works I moved the drawing over to Aspire. We use Aspire to create our tool paths for the CNC. We then measured the outer edges of the monitor without compensation. The LCD monitor needed to press fit nicely into the wooden panel.

Cutting out the basic template is pretty quick and easy with the CNC router. After we have the basic frame, a quick sand all over using 80grit and 120 grit sandpaper…..then some wet and dry. A base coat of blue paint was applied and a light wash of white. Another quick sand to give it the ‘weathered’ look and a coat of clear varnish has the frame ready to seat the LCD monitor and electronics.


The Hardware

The cut-out for the LCD into the frame was just about perfect and the monitor pressed in nicely, at this stage we didn’t really even need to secure it to the screen as it was a very nice fit. (You may want to affix the frame to the monitor!) Mounting of the hobby enclosure was through 4 x self tapping screws. Just make sure you do not punch through the front of the frame. The electronics hobby box was a bit of a mash together as you can tell, but if you spend a bit more time on it, im sure you can mount everything a bit nicer than what I have.

For the wall mount we decided that the most flexible option was the LCD monitor swing arm. You need to be careful with the weight on these things, however after a bit of experimenting we found that the short arm was perfect and stable enough to hold the weight of the LCD, the frame and the electronics.


The Software

  • Raspbian OS on RPi
  • Sign Up for an account at DAKboard.com (This is a BETA web configuration I used to display items in the frame)
  • Install Chromium web browser on the PI. (A perfect browser for Kiosk mode - see Dakboard.com for install)

I stumbled accross a little web site that specialises in turning a monitor into a useful device that is actually asthetically pleasing. It involves setting up an account and setting the Pi’s web browser to kiosk mode and loading the page in full screen. Once loaded it can show data such as, Date, Time, Weather, iCal calendar entries and link to dropbox or flikr to display HD background photos. Not a bad setup, but i stress that it is in BETA and has a few bugs. I believe there are other project floating about that can do similar. (Post them in the comments, I’m keen to explore other possibilities.)


What Next?

Let me know if you want a detailed article on all the installation steps including step-by-step install of the software. Please comment below.


Raspberry Pi HAT design files

I have embarked on a journey to create a Raspberry Pi HAT for a little project of mine and I wanted to share a couple of things that I think may help you speed up your development time in the future. As of 11/5/16 I have tested out the DXF importing it into KiCad and using at the ege cut profile. The blank PCB’s test HATS we had made up fit nicley on the RPi2. As I push further on this journey I’ll continue to post any design files that I feel could help you with future iterations.


RPi HAT Files

 
 



How to Solder #101

Never used a soldering iron? Does the art of soldering seem a bit of a mystery to you? Have you tried your hand at soldering and found it difficult to produce results you’re happy with? Do you feel your soldering technique could do with some improvement? If you answered any of the above questions in the affirmative, you’re in the right place!

It is widely known in the hardware hacking community that you simply cannot take over the world if you don’t know how make connections. Connections which are both electrically and physically sound, that is. Welcome to Soldering 101 – here you will learn the basics of soldering, allowing you to make reliable electrical connections for all those projects you have in mind or in progress.


Items Required

  • Soldering Iron
  • Solder
  • Damp sponge/Tip cleaner
  • Scrap wire to practise soldering
  • Cardboard or newspaper to protect your work surface
  • Heat shrink
  • Heat gun or gas stove to shrink the heat shrink


Preparation

Clear and prepare your workspace – keep in mind that you will be wielding an implement which will be reaching over three hundred degrees Celsius. Remove anything that could be accidentally melted or could result in the application of such temperatures to any unintended surfaces (like human skin – it hurts!). Place down an old newspaper or cardboard, something with a bit of thickness to it in order to protect your work surface by insulating it from the heat of any molten solder which could fall from your connection during the process. Though it seems counter intuitive what with paper and cardboard being relatively flammable, the temperature you will be soldering with is well below the ignition point of these materials.

Prepare your soldering iron. Power it up – you’ll know you’re ready to go when the tip of your iron can melt your solder! Ensure that your tip cleaning sponge is wet – not just damp, but wet. ‘Tin’ your soldering iron tip – the process of ‘tinning’ in soldering is applying a layer of fresh solder. This is done by feeding solder onto the hot tip of your iron – you should notice a small amount of smoke followed by a nice shiny-looking soldering iron tip. Your soldering iron tip should always be clean and shiny for successful soldering.

If you cannot complete step three successfully, a set of ‘helping hands’ from your local electrical supplier may be the next best thing. During soldering, the items to be connected need to be held in contact long enough for the solder to dry – and this is more often that not easier said than done without something to hold it in place for you.


Procedure

Strip 2-4mm of insulation from the two ends of wire you wish to join. Once the insulation has been stripped, twist the conductor strands together. This prevents fraying during the soldering process.

Tin each end. This is done by squashing some solder between the wire you wish to tin and the tip of your soldering iron. Successful tinning results in a fresh, shiny appearance. You should also notice that once the solder is dry, the once flexible stranded conductor behaves more like solid wire where you have tinned it.

It is important to ensure your connection is electrically insulated to prevent any unwanted electron movement shenanigans. For a neat, secure, and professional look, use heat shrink tubing. Heat shrink is a type of electrical insulator which shrinks in diameter when heat is applied, holding it in place over bare electrical connections. The heat shrink I am using has a 2:1 shrink ratio, which means it will end up half the diameter it started with when fully shrunk. Choosing the correct diameter heat shrink for your connection is simple – it needs to be large enough to slide over the wire(s) you wish to join, but small enough so that before it shrinks to half its size, it has a firm grip on the connection!  Cut the heat shrink to a length which is longer than the length of your connection by about 4-6 times. This allows you to leave 2-3 times the length of your connection worth of heat shrink on either side of the connection, so that a seal is formed between the insulation of the wire and the heat shrink.

Slide your heat shrink over one side of the connection BEFORE soldering the two together. This is a great habit to develop for situations that would require unsoldering of the connection if the heat shrink is not slid into position before joining. This can be due to the other end of the wires being terminated with connectors that are too large to fit the appropriately sized heat shrink over, or in this particular situation where the wire is to be soldered into a loop for demonstration purposes, there is no way to slide the heat shrink into position once the ends are joined!

Time to make the join! At this stage you should have:

  • Two nicely tinned and shiny wire ends to join.
  • Heat shrink slid over one end, far enough back to prevent premature shrinking from the heat of the soldering process.
  • A nice clean, shiny soldering iron tip. If your tip is dull or covered in browny-blackish yuck, quickly and gently wipe tip through your wet sponge. Melt some fresh solder onto your tip if necessary to get that clean, shiny look.

Place the two wire ends to be joined in contact with each other. It is often easier to set up one end in a stationery position, while holding the other end in one hand, and your soldering iron in the other. This allows you to position the two ends while you apply heat to them both with the soldering iron. You should notice the point at which the solder on both ends melts and joins the two ends – this is the trickiest part! Remove the soldering iron tip from the connection the moment you notice both ends melt together, but you must hold the two ends in position until the solder hardens! If you observe closely you will notice the surface of the solder change slightly as it hardens. For connections this size allowing 5-10 seconds is enough to ensure to solder has hardened. For much larger connections this process may take a longer period of time – learn to spot that subtle visual change when solder changes from molten to solid!

Once you have made a satisfactory join (don’t be afraid to play around and practice until you get the join to your liking), it is time to install the heat shrink. The heat shrink is to be positioned such that its centre aligned with the centre of the join. To begin with, you may find the centring technique pictured useful.

Once the heat shrink is in position, fire up your heat gun (a hairdryer is inconveniently not hot enough).  Pictured you will see a gas-powered flameless heat gun which is ideal for shrinking heat shrink.

A direct flame is too hot and will damage the heat shrink, while a hair dryer does not get it hot enough to begin shrinking. While holding the connection clear of anything that could melt (think plastics), bring your heat gun closer to the heat shrink slowly until you notice it beginning to shrink. Maintain this distance while rotating your connection or moving your heat gun around your connection to ensure complete shrinkage. If you do not have access to a heat gun but have a gas stove, you’re in luck! Ignite your smallest burner and turn it down to the lowest setting. From a height of approximately 300mm slowly lower your connection toward the burner until you notice shrinking. Once shrinking begins, maintain this distance from the burner while slowly rotating your join in order to ensure complete shrinkage. You should notice the shape of the insulation and wire join start to appear through the heat shrink as it clings snugly to your connection.

And there you have it! A nice, neat, mechanically and electrically sound connection! …or is it? How do we know? We must test it, of course! Try tugging your connection apart firmly – it should hold just fine if done correctly – if not, you’re going to have to try again. If your connection can’t stand up to a controlled tug, it is a failure waiting to happen! Be thankful that you have found this flaw in your work so early allowing you to rectify it! The connection should also be electrically conductive. A simply continuity test with a multimeter is a nice way of confirming this.


Wrap it up....

And there you have it! A nice, neat, mechanically and electrically sound connection! …or is it? How do we know? We must test it, of course! Try tugging your connection apart firmly – it should hold just fine if done correctly – if not, you’re going to have to try again. If your connection can’t stand up to a controlled tug, it is a failure waiting to happen! Be thankful that you have found this flaw in your work so early allowing you to rectify it! The connection should also be electrically conductive. A simply continuity test with a multimeter is a nice way of confirming this.

Effective soldering is a wonderfully useful skill to possess in the electrical world – be sure to dedicate some time preparing connections like the one described in this tutorial until you are familiar and competent with the process, selecting some scrap wire and cutting it in order to join it again is great practice.

Be sure to ask any questions you may have in the comments section!