Controlling GPIO with your travel router

The GL-inet range of travel routers are sold with the understanding that we can use them as more than just a router. The idea of being able to interconnect them with everyday items is very appealing. They call this the ‘internet of things’. So the curiosity got the better of me and decided to see if we could do the most basic of tasks. Switch a relay module!

Sounds simple, and sure enough, once we did a bit of research, it was. Keep reading to find out the basics of setting up your GL router to trigger a relay module using the built-in GPIO pins. If the config stuff is a bit boring for you, skip directly to the working video below!


Some light reading/research

  • http://wiki.openwrt.org/doc/hardware/port.gpio (Understand how OpenWrt and GPIO works)
  • You will require a GL-inet router. We used a GL-MiFi and a GL-AR150
  • You will also require a 5V relay and some headers/jumpers to connect
  • A soldering iron


Pinouts (For reference)


Solder some header pins to your device

First of all, you will need to decide which what sort of relay you are going to use and which pins to utilize. I only had 5V relay spare, thus I need to grab 5v from the board and a signal from a GPIO pin. Connect the 5V + and GND up and the signal/GPIO.

The gallery above has the pinouts for the GL-MiFi and the AR-150. Check these to determine the pins you want to use.


Add some config to the router

SSH into your router, locate the file: /etc/rc.local – Add the config below. Remember to set the pin number to the GPIO you intend to use. This will enable ‘output’ on that particular GPIO. Also, make sure you insert before ‘exit 0’


Add some config to the router

Shutdown your router. Connect up your relay to the 5V source, and the GPIO you selected in the rc.local config. Power back on your router, SSH back in and run the commands below. “1” will turn the relay on, and “0” should change the state so that it is off.



REVIEW: GL-MiFi 4G Smart Travel Router

If like me, you travel a lot, then having a solid travel router that allows me to work on the move securely and with anonymity is a necessity. The GL-MiFi router has proven to be a solid and reliable unit that has some perks that other travel routers cannot match. This review will cover some of the pros and cons. However, saying that, the Pros far outweigh the cons!

The GL-MiFi is powered by an Atheros AR9331 processor, is small, lightweight and contains a slot for various PCIe 3G or 4G modules. Combine that with 150Mbps Wi-Fi and you have yourself a very powerful little device. The GL-Mifi runs an embedded OpenWrt system, is extremely extendable via hardware and software. It can be used in mobile applications, industrial, commercial or at home.


Pros

  • 3G/4G capable
  • Built in Battery for mobile use
  • OpenVPN client capable
  • Excellent portability
  • 6-8hrs uptime on battery

Cons

  • When trying to charge the battery, router turns on.
  • GL-inet frontend software can be clunky at times.
  • Sim card can easily be inserted incorrectly.



Specifications

CPU  Atheros AR9331, @400MHz
Memory  DDR 64MB/ FLASH 16MB
Interfaces  1 WAN, 1LAN, 1 USB2.0, 1 micro USB (power), SIM card slot, MicroSD card slot, Antenna SMA mount holes
Frequency  2.4GHz
Transmission rate  150Mbps
Tx power (maximum)  18dBm
Protocol  802.11 b/g/n
Power supply 5V/2A
Power consumption  <3W
Dimension, Weight 105*72*27mm, 170g


The Hardware

When you first get your hands on the router, you notice that the enclosure is very solid. (As you can tell, I have dropped this unit twice… and it still works!) Nothing about the physical form of this router says “cheap” or “made in China”, The quality is second to none. All clips, buttons, and panels feel as if they will last the distance. This gives me confidence, I was certainly not afraid to throw it in my backpack with all the other crap I carry around.


3G/4G Module(s)

One of the standout inclusions in this travel router is the modulized 3G/4G PCIe cards that can be included. We ordered the Quectel EC25-AU with the unit. The seamless integration of this module with the built-in WiFi means that we can share a 3G/4G connection with as many devices as we need to. The configuration is as easy as inserting a sim card and selecting the region and provider. The module connects very quickly, so long as you have a data plan you will have connectivity to the internet. Of all the GL-inet travel routers the GL-MiFi is the only one with integrated cellular. Sure the other travel routers can use a USB dongle and tether, but nothing beats the quality and reliability of these built-in modules. For more info on the Quectel 3G/4G modules check them out here.


The Software

The GL-MiFi runs an OpenWrt firmware with a custom front-end user interface for its users. I think the ‘vastness’ of the LuCi interface could be a bit daunting for some, so they decided to write a front-end graphical user interface (GUI) that is easier to use and understand. From a basic user point of view, I think they achieved this goal. However some of the more advanced tasks you still need to achieve from the LuCi interface.

The custom interface interacts with OpenWrt and at times can feel a little bit clunky. Firmware improvements are being rolled out all the time and in the few months I have had the unit, I can see that the GL-inet crew are developing this frontend and fixing bugs as they come up.


The Fun Stuff

By Far the coolest part of the GL-inet routers is the fact that they can operate as an OpenVPN client and a Tor router. (We will do a post soon on setting up as a Tor router.) However, for now, we are going to focus on the OpenVPN side of the device. The OpenVPN client can be used in two ways. Either connect to your own self-hosted VPN server or connect to one of the popular paid VPN services. The paid services allowing anonymity and safety of your data whilst traveling, or operate through your own self-hosted VPN for access back into your business or home network. A typical setup of the OpenVPN service through a paid provider can be found here. (The setup on this router is the same for the MiFi)

If you have a keen eye on the GL-inet routers then you might have also seen in the newest firmware an ‘OpenVPN server’ being rolled out in beta form. I am yet to have a play with this, however, it is exciting to see a device no bigger than a rich-mans wallet hosting its own VPN server.


What next?

So many cool things still yet to be achieved with this router. Here is my list, in no particular order, of the bits and pieces I want to achieve.

  • Solar power kit to run the MiFi indefinitely.
  • Run up the Tor firmware.
  • Look at Mesh firmware
  • 3G/4G VPN tunnels into other networks
  • Control relays from GPIO pins onboard.

If you have any thoughts on what else we could do here, let us know in the comments below. Very keen to get your thoughts!!!



How to setup VPN on a mini travel router

In this scenario we want to use a mini travel router to act as a VPN client so that when we connect any device to it we know the data will be safe and traverse via a VPN. This kind of setup has a few benefits. The first being the fact that we only need to load one VPN config onto the router and any device that connects to it will use the VPN. This saves us time in setting up our phone, PC or tablet with the VPN config. We can assume that when connected to the travel router we are using the VPN.

The second is portability and travel. Using the travel router in a hotel or a restaurant means that our data is safe and secure. (Assuming you connect to the local wifi with the travel router in bridge mode.)

For this demo we have decided to use the GL-AR300M Mini smart router. This router acts as an OpenVPN client which is what sets these small devices apart from any others. Not all travel routers have this functionality.


Signing up to a VPN service

The first thing we need to do is sign up to a VPN service. Yes we could run our own VPN server, but whats the point when you can get top class servers and better speeds for a few dollars a month. Not all VPN services are alike. Some keep logs, some don’t, some allow P2P traffic, some don’t (Few VPNs have been able to prove they don’t keep logs….but from a security point of view, a VPN with no logs suits us the best.) We also want to look at where the servers reside and what services we can put over the VPN. For example we do not want to connect to a server in Europe if we are located in Australia. However the Australian server may not allow P2P traffic or torrenting. These are just a few of the things to consider when signing up.

We use IPvanish, it is a reliable, no logging VPN services which we have no issues with. Feel free to give it a go. Or do a quick google search and you will be inundated with services to use.


Where to obtain the config files for OpenVPN?

As we are using the GL-AR300M and it uses the OpenVPN protocol we must search our VPN provider for an OpenVPN configuration and certificate. Without this we cannot connect securely to the VPN service. Most services will have a location and the files will be split into servers. Pick the server you require and download the OpenVPN config and certificate. In out case we downloaded every single OpenVPN config for all servers. We then extracted the config we wanted (A Melbourne based server) and created a .zip file with only that config and the certificate.


Loading the config onto the travel router

Depending on how the OpenVPN config is delivered to you, there may be an additional step to create a zip file with the certificate and the config. At times the OpenVPN config file can include the certificate. But generally for VPN services a separate VPN certificate is used.

Log into the GUI of your router and located the OpenVPN tab. From here we can either upload the OpenVPN config or our ZIP file containing the config and the certificate. Once installed, we can then go ahead and activate the VPN profile. You will see a log at the bottom which indicates if/when it is connected and how much data is passing over the VPN. You can also look into using other settings to confirm that the VPN is being used.

You may be greeted with some VPN authentication. You only need to do this once and it is most likely the same login that you use for the VPN service. For IPVanish it will be the email that you registered with and the same password you use to log into the website.

Once Authenticated, the VPN should be good to go, simply click the ‘enable’ checkbox and ‘apply’ the settings. You should then see the VPN begin to connect. If you get errors in the log at this stage it will be an error with the certificate, OpenVPN config or your Authentication. It is possible to load up multiple OpenVPN configs. Use the dropdown box to select the server/config you want to connect through then click apply.


Some assumptions we have made...

This tutorial assumes that you have already connected your travel router to a hotspot with internet ie. Hotel, Maccas, Home. Obviously this is the link that we will tunnel through with our VPN service. There are some settings to ensure that internet does not work without a VPN connection. This ensures that the VPN is being used at all times. Also we set the DNS to use Google DNS. (8.8.8.8 as primary and 8.8.4.4 as alternate.)


Confirm VPN is working

One way to confirm that your internet traffic is travelling through the VPN is to use the https://ipleak.net/ website when you are connected. You should see that ‘your’ IP address is that of the VPN server you have selected. Also can check to make sure the DNS servers being used are masked.


Powering Ubiquiti links from 12v

So it seems that I can power a Ubiquiti Bullet and Rocket directly with DC 12v. In the past I have been chasing POE and wasting precious milli-watts converting 12V to POE standard (Usually 24v or 48v) then powering the devices.  A power saving can be made by connecting direct to 12V. If using a solar setup, the power savings can mean more up-time, and better use of your batteries. Some testing will follow this blog post. However in the interim, it seems pretty stable here in the workshop.


How to make your own cable for 12v power supply.

  • RJ-45
  • RJ-35 Crimp
  • Pliers
  • Box Cutter
  • Straight through Ethernet cable

In a nutshell, the Ubiquiti Bullets and Rockets grab power from 4 pins on a standard RJ-45 connector. In our case here in Australia (Blue/White-Blue) pins 4 & 5 will carry 12v+ and pins 7/8 12v-.


Prepare your cable

If you have the resources to cut up a straight-through cable, then go ahead and cut one end off. (Otherwise you will have to complete two terminations) Strip the cable back a bit to expose the pairs of wires. Identify the solid blue and Blue-White wires. These will be your 12V Positive injection points. Now identify the Solid Brown and Brown-White wires. This will be your 12V Negative injection point. From here identify the remaining cores and insert them into an RJ-45 housing.

  • PIN 1 – White-Orange
  • PIN 2 – Orange
  • PIN 3 – White-Green
  • PIN 6 – Green

Now crimp your RJ-45 and you are all done. The bare wires can be used in anyway to inject 12v. ie Barrel jack. I would use a fuse close to the source to protect your equipment. Also confirm the pinouts prior to plugging in. The last thing you want is to fry your Ubiquiti gear.


Or Don't hack up a cable and buy some injectors

If you want that more professional look, then you can always purchase a few of these injectors. Have a look at the specs though and make sure the power inputs are on pins 4/5 and 7/8. Let me know how your setup goes? I really need to do some testing on the longevity of this type of setup. My only concern is that the fluctuating 12v from batteries could damage the Ubiquiti gear over time. Maybe I need to look at a circuit to provide clean power.



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 as the edge cut profile. The blank PCB’s test HATS we had made up fit nicely 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.

I can confirm that this fits onto the rPi3 also.


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 to 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!