Den Automation – Unboxing

It’s been a long time in the making, but Den Automation finally started fulfilling their pre-orders earlier this month. I received my pre-ordered items, an order I placed in March 2018, last Monday. I’ve been looking forward to getting my hands on some Den gear since I first heard about the company in 2017. I love to dabble in home automation and the idea of a light switch that was a drop in replacement for a “dumb” light switch sparked joy!

I should point out that I’m an investor in Den Automation, holding a few shares that I bought through Seedrs.

So, what did I buy?

  • Smart Hub (required to control everything else)
  • Four One-Gang switches
  • One Double Gang socket

Den, as a thank you, threw in a remote too. That was a nice surprise.

The packaging looks nice and reminds me a little of Nest product packaging, with a nice sleeve surrounding the box.

The Smart Hub

The Smart Hub is the brains of the operation.

Opening up the Smart Hub Box.
The contents – The Hub, Some instructions, an Ethernet cable, power cable, adapter and mounting screws.

The hub itself was a little smaller than I expected. It was very light in weight. If I’m honest, it does feel a little cheap, but I’m only comparing that a Google WiFi unit that I had close at hand. That said, it didn’t feel flimsy and the connectors were solid when I plugged in the power and Ethernet cables. I was surprised that the power connector on the hub itself wasn’t USB. I was also surprised the Smart Hub required an Ethernet connection.

The Smart Switch

This particular device was the reason I love Den’s concept. Smart WiFi switches are nothing new, but most are either touch based or require a neutral connection (like Sonoff’s offerings). I like the old fashioned rocker switch. Familiar and reliable. Lightwave RF have offered WiFi switches for a long time, but I’ve never taken to their push button design.

An extra earth wire, additional screws, spacing plate and switch.

On lifting the switch out and flicking the rocker a few time, I have to admit I felt a little disappointed. The rocker lacked the weight I’m used to. I handed it to my wife and she agreed. Of course, it’s easy to criticise something like this and, weighting aside, we agreed to reserve final judgement until I’d installed them. Having something that can flick itself on and off is *never* going to as solid as something manual.

The spacing plate is provided in case the backing box isn’t deep enough. it was well packaged, being hidden under the insert. This meant it didn’t get in the way of the Switch itself and the box was opened.

The insert contains a message to slip the box over. Wasn’t very obvious! I knew the spacer was included and lifted the insert out in search of it. That message probably needs to more obvious?

I read some of Den Automation’s early tweets and the use of Earth is crucial to the operation of their light switches, so I’m glad the included some extra cabling.

The Smart Socket

I ordered a Smart Socket just to try it out. I currently use one Sonoff Smart Plug to controlling power to my TV. It’s used a lot (the standby on my ten year old telly draws more wattage than I’d care to admit). The sockets in my house are brushed steel downstairs, but the sockets behind my TV aren’t visible, so I think this is a natural place. It will mean I turn off both my Apple TV and the TV itself.

Smart Tags, screws, the spacer and the double socket

One of the things that Den have done in this space is something I personally find very clever. They have created a concept of Smart Tags. These little tags fit over a plug and can be used to identify an appliance or item.

The socket included four smart tags

I haven’t tested them out yet, but the idea is as following. You pair a tag with an appliance i.e. a hair dryer. When you plug it in, the socket *knows* what’s plugged in. The example Den give is around hair straighteners and a person leaving them plugged in and turned on. I think it’s innovative, but requires every socket in your house to be a Den Socket (I don’t know if they have a patent on this idea).

As a neat touch, Den also put a Smart Tag on the power supply for the Smart Hub. That made me smile!

The Smart Hub power adaptor came fitted with a Smart Tag

The Remote

As a gesture of goodwill, for the numerous delays in shipping, Den chucked in a free remote.

It seems to just be an on or off type deal, but I don’t know anything beyond that. I assume you can pair it to one or more sockets or switches in the Den App. Once I get everything setup, I’ll be sure to write more about it.

Summary

The packaging was nice and well presented, but the items themselves felt a little cheap. It’s hard to explain. I have put this feeling down to the type of plastic and how it feels. The weight of the items also feeds into that feeling too. I know it’s pointless to try and gauge quality by the weight or feel of something and I’ll reserve judgement until I’ve installed them and used them.

I’ll do another post on the setup once I get more time.

I’m happy to answer any questions you might have. I think it’s fantastic that a small UK startup are producing products like this and that they have finally shipping is a testament to their hard work and determination. I’ve played no part in the development of the product, nor do I personally know anyone involved, but I can appreciate the monumental effort required to deliver hardware and software, especially consumer facing.

I take my hat off to Yasser and his team.

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Project: Water Softener Salt Level Detector

In my house, I have a water softener. This requires topping up with salt at varying intervals, depending on the usage. In the year I’ve been living here, I’ve forgotten twice. Whilst it’s not the end of the world, it does mean that we get some limescale build up on the taps and, more annoyingly, the shower head. I’ve tried a recurring calendar entry to remind me, but the reminds would happen pop up when I was at work, or out and about etc. By the time I got home, I’d forgotten about it. This sort of small annoyance was something I felt could be fixed with a overly complicated, time consuming, technological solution!

The problem

My water softener has a large compartment at the front, which you fill with salt tablets. Overtime, these get used up as the software regenerates itself.

I wanted a way to detect when the level of the salt had dropped to a low level.

How to measure the level?

My first pass at this problem involved using ultra sonic ranging device. I purchased a simple unit that was good for distances up to three metres. More than enough for my needs. To power this unit and make the necessary calculations, I chose a Raspberry Pi Zero, the latest entry to the Raspberry Pi Family. At about £9 it seemed like a good option to get me started on my first IoT project. To be honest, I bought one on a whim and needed to put it to work!

I connected it all up and, in testing, it worked very well. I went as far as to build a simple iOS app to display the current level (I even build a simple web page with SignalR!!!)  Unfortunately, it was useless when it came to the salt. Ultrasonic works best with flat surfaces and the top of the a pile of salt tables is anything but level! I thought about placing a piece of word or plastic on top of the pile, but this seemed like a hack. Okay, the whole thing is a hack, but I have to maintain some standards!

I went back to the web and started researching how people measure levels like this in real life, coal bunkers and whatnot. They use lasers. I didn’t want to spend any more money than absolutely necessary, so I would need a different approach.

The idea when struck me that I could use a reed switch (one that turns on in the presence of a magnetic field) and a wooden rod with a small magnet on it. The rod would rest of the pile of salt and move downwards, inching the magnet closer to the switch. On paper, this seemed like it would work, but in practice, I didn’t have enough space above the softener for the rod to protrude.

 

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The initial circuit board with the reed switch

I then had another brainwave. Replace the rod with a piece of string and a weight! The effect was the same, but it didn’t require the space! Genius.

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Waterproofing the *complex* electronics

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A lid with the mechanism attached

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Side view showing the string coming through

I put all the electronics into a water proof box and fed in the USB power cable. I added some LEDs to give me some idea it was working (green indicated my software was running and red indicated low salt). I moved the reed switch to the end of a piece of cable, so I could better position it. Some gorilla tape and a straw (to ensure the string moved unimpeded) and my contraption was complete!

I mounted the contraption onto my softener, replacing the lid.

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The software is designed to send me an alert once the salt runs low. As tempted as I was to write my own app and host a back end server, sanity prevailed and I just used IFTTT to raise an alert.

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An IFTTT alert telling me to top up the salt

Summary

The contraption has been in place now for a few months (it’s taken me that long to write this bloody blog post!) and it’s not been a mixed bag. I’ve gotten one alert, which arrived at 3 in the morning. Another time, I just checked the softener on a whim to discover that the salt was low, but the string had snagged and got stuck. I freed it and a second later got the IFTTT alert. At least it proved my python script was reliable.

I’ve put some plastic on top of the wood to ensure the string never snags again and I’m expecting an alert in the next few weeks.

The future?

With version one in place and working, I’ve started thinking about version 2. These are the improvements I plan on making:

  1. Switch to an MCU (Micro Control Unit). The Pi is great, but it’s overkill (running a full OS) and uses much more power than necessary. The NodeMCU board, for example, can be put into a deep sleep, which users very little power.
  2. Replace the breadboard with a PCB to reduce space.
  3. Trigger the measurement at fixed intervals and only notify me when I’m *actually* home. The last part I’m not sure about, but I suspect IFTTT can *know* where you are.
  4. Potentially use an IR sensor for distance measurement. Whilst this would eliminate any moving parts, it would require a hole into the salt holder and I’m worried that water might splash out or onto it.

Best laid plans, part 2

After my little boo-boo with measurements, I purchased a new Wiska junction box from RS, this time with a little more width and the Sonoff relay fit perfectly! I also picked up some IP66 glands to help secure the wire from the LED strip.

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This junction box had a membrane covering each hole, so I pierced a hole in it and fed the table through. The gland then screwed into the threaded hole (what makes these Wiska boxes so great).

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I tightened it all up.

Sadly, I didn’t take any pictures of my SWA cable gland process as I did it at lunch time. This was the tricky part of my installation since it required a hacksaw. I found a great YouTube (https://www.youtube.com/watch?v=epmxqFiD9JI)  video and followed that as best I could. I didn’t have the “glanding spanners” as recommended, but I made do with pliers. I do plan on using another armoured cable to connect to the other side of the garden, so I’ll take photos of that.

Anyway, with everything installed, I dropped the box in the garden.

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You can see the thick black SWA cable and the thin LED cable. I should point out that this is not the final resting place of this box!

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The lights look pretty nice in the snow and light the garden pretty well.

This weekend I plan on getting a few metres of SWA and using the small junction box to hook up the lights on the other side of the garden!

Best laid plans…

Wanted to work on my garden LED lighting project weekend. Unfortunately, I may have made a slight miscalculation with my measurements…

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I placed an other with RS for a replacement box, this time a little wider! If all else fails I can always take the circuit board out of the case and place it directly in the junction box, but I’d rather keep it housed.

I did manage to test it out though and the lighting is effective enough.

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Maybe next weekend?

 

WiFi enabling my porch light with a Sonoff Basic Smart Switch.

Having failed to read the warning regarding neutral wires, my attempt at using a Sonoff T1 Smart Switch to control my porch light went down in flames. My plan B was to try using a Sonoff Basic WiFi Smart Switch to perform the same job. My plan to put the relay between the ceiling rose and the bulb holder. It wouldn’t be pretty, but the aim was to test utility before spending £££ on proper smart switches etc.

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As you can see, my porch light is pretty standard.

First step, I turned off the power at the fuse box. Can’t stress this one enough. Don’t go near any mains electricity until you’ve isolated the power. Don’t just turn off the light switch!! I gathered all the parts and tools I’d need.

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I then disconnected the light bulb holder, removing the little red plastic thing and the curved lid.

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Using a short piece of flex, I connected the Smart Switch directly to the light bulb holder.

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Next, I connected the Smart Switch to the cable hanging from the ceiling!

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As it was hanging a bit low in the porch now, I created a loop and used two tie-wraps to hold it in place.

As it was all hooked up, I turned the power back on. Nothing started to smoke, so I knew I’d gotten that part done okay. The green light appeared on the relay and I started the pairing process. This involved holding down a black switch on the relay for a few seconds until the green light started flashing quickly.

I then launched the EWeLink app and hit the Add Device button. The process is straight forward. When you push the button down on the device, it creates its own WiFi network. You then connect to that WiFi network, enter details of your own WiFi network (SSID and password) and it then connects itself to your EWe account.

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Following the instructions, I found the Smart Switch’s WiFi point and connected.

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Once connected, the pairing process starts.

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After a few seconds, you’ll be able to control the device! I tapped on the power and, eh voila, the light came on.

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Job done!

Smart switches and the missing neutral!

As part of my learning and experimentation with Homekit and home automation, I recently picked up some Sonoff Basic Smart Switches. I’ve successfully installed one them outside, controlling a few metres of LED strip lighting.

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It’s pretty novel to turn it on and off via Alexa or from my iPhone, but to be honest, it’s not very practical. Flicking a switch is just than saying “Alexa, <pause> turn on the side alley light”. Pause. <click>. “Ok”.  Whilst voice control gives you flexibility (hands full etc.), 99% of the time the light switch is the king.

In my quest to check whether the smart home is practical, I wanted to try out a proper, in the wall, smart switch. I’d found a few companies such as Den Automation (who I’ve actually invested in, but who’s stuff isn’t on sale yet) and Lightwave RF, who make normal looking switches (normal from a UK style). The downside is that this stuff is expensive.

Taking Lightwave for example, a single Lightwave switch will run you £60. They also require a hub or bridge, which means an additional outlay of over £120 before you can even use the switch! Spending the bones of £200 just to check whether a smart switch is useful or useless is a bit much. I needed something cheaper to get me started!

Enter the Sonoff T1 WiFi lightswitch

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I dropped £31 and bought two switches, a two-gang and a three-gang. Aesthetically, I don’t find them appealing since they are just white and I hate touch buttons, preferring something that actually clicks.

I digress. The first step with any new light switch is to actually install it in your house. For me, I wanted to get the maximum value, so I opted to replace the three gang switch in my hallway. The hallway light switch operates the hall light, the porch light and the upstairs light. Three lights that are used pretty frequently.

I started by unscrewing the switch.

Then I stopped.

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There were more wires than I expected!! I knew the upstairs light and the hallway light were three-way switched, but the porch light isn’t.

The back of the T1 looks like this:

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I was going to need some professional help! Thankfully, as my father and two of my brothers are electricians, I could get *free* professional advice.

After getting a handle on the wiring, I realised that the T1 switches just wouldn’t work. No neutral connection was available. I mistakenly the blue wire to be neutral when it is switched live. I should have paid more attention when my father was teaching me this at age 15. I checked a few more of the switches and confirmed that there was no neutral in any of them.

The listing for the Sonoff switches on Amazon does indicate that a neutral is required, but since I mistook the blue switched-live for a neutral, I went ahead and bought them. I’ll be returning them.

This was a disappointment.

My main annoyance was that I’ve only had my house completely rewired last year. I was kicking myself because this should have been something I was aware of. That said, a lost of forum entries seem to indicate that most electricians won’t add a neutral that doesn’t connect to anything. Even if I did ask my electrician to add a neutral to each switch, he could very well have said no.

At this point, I took a step back. The Sonoff switches simply weren’t going to work.

The Lightwave RF stuff was too expensive for the purpose of playing around.

I needed a plan B. I decided to put one of the Sonoff Basic Smart Switch onto my porch light. This would mean leaving it switched on at the wall, but I figured that would be okay. I’ll do another post on that soon.