Several of you have asked where I’ve been this week and what I’ve been doing – so here it is..
On Wednesday I flew down to Southampton (from Newcastle) in the morning to embark on what is now the second Richmond event I’ve attended… the annual IT Director’s Forum. The journey consisted of the flight and a train ride to Southampton Central station.
Thanks to flight times etc., I ended up with some time to burn and went for a short visit to the West Quays Shopping Centre, nothing to write home about but a pleasant and modern centre with a decent mix of the usual imagination-less chair restaurants, the only exception in my view being Pizza Express who do a pretty good imitation of a real pizza – and that’s where I had lunch.
Looking at the street signs the docks didn’t look that far away so rather than taking the planned shuttle bus as per the previous year, I walked down to the docks. Won’t do that again,the weather was nice but it was quite a hike and I arrived at Dock 10 late afternoon in time to board the Aurora with utterly flattened feet.
Once safely on-board the Aurora (a P&O ship able to handle 1200 passengers – the smallest of the fleet) I attended the opening talk by the proprietor of Richmond events who broke the bad news that the broadband was going to be crap throughout the event.
This was swiftly followed by a keynote speech by Mary Portas who described her experiences and views on everything from the smallest stores struggling to come into the 21st century through to the largest supermarket chains.
Considering that Mary’s website describes her as “the UK’s foremost authority on retail and brand communication, I must say I didn’t entirely agree with everything she said, especially on supermarkets and didn’t consider her that inspirational but non-the-less she managed to entertain everyone. With all on-board, mid-evening we set off on our journey to the channel Islands which was to take most of the night. Dinner was a casual affair and our hosts were pleasantly un-commercial – we all had a nice time.
Shortly after arriving on the board, I’d met up briefly with Elle who is one of the organisers and it’s really nice that she’s been reading my blog since last year and keeping up with what I’ve been doing so I hope she likes this.
With the ship under way to our destination just a few miles docked off the channel islands, dinner was fine if a little pretentious (“Braised Pave of beef” and other strange titles such as “Baked Tartiflette Potatoes littered the menu) but the important point of course was that the hopeful suppliers paid for the drinks. The night was interesting – I’ve no gripes about my room, balcony view of the sea and sizeable area for a ship, the room was comfortable, the movement in the face of considerable sea-power was not. Everyone commented next morning that the night was “rough”.
So the way this works is simple enough – 3-night cruise, sponsored by sales organisations – IT directors and professionals get the decent rooms around the outside of the ship, the sales people get the inner rooms – they pay, we don’t – simple enough. In return we agree to meet them in short matchmaking sessions in between insightful seminars – obviously they hope we’ll do business and in many cases that works.
All in all though it takes a bit of stamina, a worthwhile two whole days of which I’ve just finished the first. Saturday morning we disembark – I’ll be taking the coach this time to the central train station which is then just one stop to the airport. Should be back by lunchtime Saturday which is great as I’ve some R&D to do before we have friends over for the evening.
Thursday morning we started bright and early, breakfast sponsored in my case by a company called Capita. Breakfast was ok but it’s the one meal of the day I’d rather have a buffet. I went on to participate in a discussion on BIG DATA which was more than useful followed by another REALLY interesting discussion on mobile access and security. In each case a facilitator enabled maybe a dozen of us to collaborate and share ideas.
I facilitated a couple of these discussions the previous year and it was gratifying that some folk remembered me! I then listened to a talk by John Amaechi MBE, a psychologist who is notable by his basketball background and the fact that he stands 6ft 9 inches and 23 stones in weight (and has size 15 shoes) – very interesting as he described the difference between good and bad management.
Lunch was great – I met a couple of people I’m sure to keep in touch with as we have similar interests. After a couple of business meetings in the afternoon, I attended a talk by David Smith – economic editor of the Sunday times who made some predictions for the future and described the on-going effects of the recession – interesting that China is now the leading economy and the entire wealth of the world is steadily moving in that direction.
We had a great session with Clive Panto who put us through some intelligence tests which I have to say my group failed miserably but had a REALLY good laugh in the process (If I tell you that one of the tests was to drop an egg from the ceiling to the ground without breaking it – within 5 minutes we’d broken our first egg and when it came to the presentation of results, which I did – we had the perfect solution, sadly as I was just about to climb the ladders to the ceiling (yes, on a moving ship) the egg fell out of my hands and smashed on the floor which resulted in lots of laughter..
Well, it’s an IT director’s event – I figured open neck might be more the norm – that’s what I get for thinking. I was not however alone by any means.
Friday and more business “dating” meetings, some talks including one about the automation of life and work in the age of smart machines (in which I’m particularly interested of course as someone deeply entrenched in the “Internet of Things”) and the question in one talk was asked “are we innovating ourselves out of the door. The last session of the day was a wine and cheese tasting event, I found time to go soak in the pool, visit a short cheese and wine testing and then the second formal dinner.
And that, in a nutshell, is that. Hope you found the blog interesting. And just for that… here’s a picture of some cows I took on the way home and a map showing where the ship was docked for the duration.
Streuth.. I’ve just realised I’ve been running this blog since 2005! Doesn’t time fly. My interest in using Atmel technology for home control started with an article I wrote back in 2012 simply called “Home Thermostat”. At that time I was just playing – but messing with prototypes really isn’t much fun so shortly thereafter I design the “UberBareBoard”. That article was followed up by my first attempt at home control over the Internet and part 2 by which time I was starting to see some real potential for not only my home but our holiday cottage business and for our place in Spain. Then came more updates as I got to grips with the more powerful Atmega1284p chip and started to develop my own PC-based test tools. By July I had it all figured out – or so I thought – using RF24NETWORK software providing a mesh-type network of radios still using the NRF24L01 radio.
Amazing how things change. The NRF24L01 boards which – I’ll grant you are cheap, continue to function poorly –they do not like stone walls and the RF24NETWORK is not a true mesh – you have to specify every node in the mesh which makes replacing boards a lot of fun.. and it really cannot handle one of the boards going offline. Finally, no-one has yet made effective use of interrupts when using these radio boards in a network – which puts further limitations on what you can do – as you spend your time constantly polling the radio network.
Over the summer, my pal Aidan and I have been working hard – we now have a decent Atmega 1284-based board to work with – you’ll see it below. Late July I discovered the Radiohead library – the nearest our little processors have come to seeing a proper mesh network.. but that now pushes the 328 chips out of the window – as the library takes them near the limit of their available program memory and as for the tiny 2K of RAM – just not enough. For boards at the end of the chain, perhaps – and I have 3 working installations using these – but for the master board, the 328 is no longer an option.
In August while enjoying the sun, it hit me – the NRF24L01 chips don’t have the ability to know how strong the incoming radio signal is – so how the hell can a network possibly know which is the best unit to route the signal through – and that started me on the hunt for alternatives – which brings us neatly into this post.
If you’ve been following my blogs you’ll know about my on-going work on home control but firstly you’ll see the phrase “Arduino” bandied around. I use this merely for convenience as I use a lot of the Arduino libraries out there – but my boards are home-grown. I’m particularly fond of the Atmega1284p chip because, unlike the standard Arduinos you see our there, this has 4* the RAM – which means it’s less likely to run out. It also has 4* the FLASH memory – so just when Arduino sketches are running out of room, the 1284p is just getting started.
I used to use hand-made boards and there are plenty of those lying around, but these days I’m using a design we put together called the “Aiduino” – so-called because my pal Aidan did the board layout. This particular design has stood the test of time and I use these on everything. It has space for both 3v3 and 5v regulators, the chip, the usual support components and that’s about it.
You’ll see a typical Aiduino above with edge connectors for all the port pins and an SPI connector near the middle. I don’t bother putting the programming interface on the board as the low-cost FDDI interfaces do that all for you – why waste valuable board space. I simply allocate a 6-way connector on the edge of the board for programming.
Armed with these boards, I have LCD display controllers (for wall mount displays), a master controller with Ethernet card and “slave” units to control lighting etc. All of these units talk to each other using NRF24L01 radios which are very cheap 2,4Ghz popular radio modules. There are two problems with these radios – firstly they are very low power and secondly they are on the same radio broadcast range as just about everything else including WIFI – and they DON’T like stone walls.
I’ve looked at the cheap FSK units as used in radio remotes – no-where near powerful enough.
Aidan and I are investigating some Atmel chips with on-board radio – these look promising but getting all of that running in the Arduino IDE and hence keeping access to the Arduino libraries – is proving a challenge but watch this space as he’s working on this right this minute. We’d like to produce (where others have failed) a tiny radio module which runs on SPI and which internally handles all the mesh coding and massive buffering – as well as offering other functions to take the load off the main boards.. Meanwhile…
I’ve looked at the RF22 modules – but these come from the USA and hence are a little expensive (inc. postage).. but only in the last few weeks have I discovered even cheaper Si4332-based radio boards from China which are compatible with the RF22 modules and hence can work with the likes of the Radiohead library for Arduino – a simple but fully functional “mesh radio” library. Not only that but these radios and library combined, unlike the slightly less expensive (but only just) NRF24L01 units, make good use of interrupts to ensure you can actually do something else while the radios are working!!
See the radio on the right – that’s one of them. They are tiny which poses a problem for prototyping as the edge connector is 0.05” pitch – but it’s do-able with care.
Below you’ll see one of my bodged Aiduinos which has the radio board mounted on top of the 1284P chip. If this all pans out I’ll make a board that incorporates the radio… and in the process of research I’ve found out some interesting things about these little radios.
I can say that I’ve had 3 of these running in mesh mode and the range covered by 3 equally spaced units (the centre one acting merely as a message relay in this case) covers from my garage, to my greenhouse – through 4 stone walls and an intermediate lightweight wall – which is WAY better than the NRF24L01 chips can manage.
At first I managing a couple of message round trips a second – I needed to get the speed up to dozens of round trips a second in order to allow me to, for example round-robin poll several units to update the mobile phone.
Well that worked too thanks to some help from the designer of the Radiohead library – a change from the library defaults brought me to 100 package round trips a second – when I say package – we’re talking about, say a 20 byte package going there and back – and with additional maintenance bytes (from, to, ID etc.)
The chip used in these radios, the Si4332 is supposed to handle a maximum +20db output – I managed +17db – but I’m convinced the little spring aerials are now the limiting factor – with full power I can now get through 2 stone walls but not right across the house.. but WAY better than the NRF24L01 chips even when the latter have stub aerials.
To run these radio boards, they need 3v3 power. Our Aiduinos run on 5v but have 3v3 out. You can feed the one output from the radio directly but the inputs to the chip might be damaged by direct connection to 5v logic – one option is a level convertor, another is a resistive divider. I found that for the 3 inputs that need it, 470r series resistors do the job just fine (The NRF chips work off 3v3 but will accept 5v signals directly). Why don’t I just run everything off 3v3? Speed and driving other devices, that’s why.
I’ve now modified the Radiohead library so that I can also get a flag when data is passed THROUGH the unit so it’s now possible to indicate the success of not only incoming packets but those passed on elsewhere – very handy for debugging and there’s nothing wrong with pretty lights anyway.
So there it is – what looks like a reasonably inexpensive radio solution for home control and with a tiny mod, the standard Ethernet library handles the Atmega 1284 chips no problem – it’s detailed in here somewhere but boils down to adding the chip to one of the library conditionals for the Mega boards. I did notice when these radios are running constantly, a slight decrease in range of my plug-in-the-wall mains controller handsets as they are on the same frequency range – but in my application, such all-out non-stop transmission would only occur when say the mobile phone is actually polling the units – otherwise it’s just about occasional updates and checks. As for the handsets interfering with the network – they don’t – maybe thanks to the frequency-hopping technology embedded in the boards. Incredible technology for such a low price.
Far more to come in the future. I plan to add moisture detection for our plants, gas monitoring for the home, I already have lighting and heating control working in 2 of the properties. I also have IR remote control and radio mains control underway. Do look in.
This is the latest to date in my series of articles on home control which started with my original article on a cottage thermostat in which I envisaged a very simple controller. Then came the UberBareBoard article about an Atmega328-based Arduino clone, initial attempts to master the NRF24L01 radio. The next article was the first item entitled home control and after this – then part 2 and then the winter update – then the April 2014 update and then things really started to move as I discovered better networks – then came the full mesh article – by this time I had everything starting to run the way I wanted things but for the radio network – as you’ll realise by now, that issue is starting to disappear.
Why should you read this? Are you interested in reducing your USB gadget charging time by up to SIX TIMES? Do you want to fast-charge your phone or tablet as never before?
For some time now the subject of USB power supplies has been in the back of my mind.
How many times do you hear "this is taking AGES to charge"? How many people wonder about their tablet chargers or the leads? Why do some chargers and leads work well and others not?
Well, it’s simple enough really – the more current you put into a device (within limits) the faster it charges – but what’s the bottleneck? Why do car chargers sometimes take ages where a plug in the wall charger might do better?
To start with – the original specification for USB meant that chargers need deliver no more than 500ma (half an amp) and that’s pretty useless for modern tablets with their large batteries. So, there are endless chargers out there which deliver 500ma or much LESS. But unless stated, how are you supposed to know – and in any case, it could be that they’re just not putting enough VOLTAGE out (the specification is 5v but there are tolerances – the cheaper the charger the further off mark it could be – at one end that is dangerous – at the other end you just get less charge).
Then there are the LEADS – some modern leads look pretty (flat coloured ribbon) – but thin leads can mean lost voltage along the length. I’ve seen some leads so thin there is NO chance of them delivering high current.
There is ONE way to test this – simply look to see how much CURRENT is being delivered – then you can check all combinations of your LEADs and your CHARGERS to see what’s best for your phone.
And how do you do that?
If you don’t want to do any messing with meters and razors – simply go to the section called TESTING – you may still learn a lot – I did! But there’s nothing really like first hand experience and results are so variable you really do need to do some testing yourself – but read to the end – HELP IS AT HAND… I’ve already placed my order!
Take a SHORT extension lead which has a full size MALE USB at one end and a full size FEMALE USB at the other (and if it isn’t short, MAKE it short but only if you know what you are doing). The chances are if you open up a USB extension lead with a razor (be careful and only do this when it’s NOT connected) you should see 4 wires inside – red, black, green and white. The latter two are data, the black is ground and the red is 5v. CUT the RED wire – and simply stick a multimeter in the path – set to high DC current.
I did this work for my own needs but you might as well reap the benefit!
To start the ball rolling simply take a short USB extension (see the image to the left- note both MALE and FEMALE connectors) and a razor. It is VITAL that this lead is short, say no more than 250mm or so. You don’t want this lead contributing to the problem!!
CAREFULLY cut the lead along it’s length for around 75mm or so, somewhere near the middle – not important where. The idea is to remove the plastic – WITHOUT cutting the leads inside – if you mess them up – bin the lead – get another – start again.
You MAY find a braid inside – or just 4 wires. If the former, fiddle with it until you can get to the wires inside. If you end up breaking the odd strand of the BRAID, it doesn’t really matter but do as little damage as you can. Just make sure you don’t break or damage the 4 wires (red, black, green, white) inside. If the wires are not coloured as stated – BIN it and get another – no point in taking chances – these are dirt cheap on Ebay.
So to recap – what we’re doing is BREAKING the +5v lead so we can insert a meter in series with it – and test how much current is flowing with different combinations of leads and chargers.
At this point you’re ready to go. Put the two meter leads into the choc block and make sure you set your meter on AMPS and not milliamps! Mine here is set to 20amps – NO WAY any charger is giving that much out so I’m safe. I can’t advise further here as all meters are different – typically you might have a COMMON connector then one marked AMPS but you’ll need to figure that out.
Here’s the fun and possibly enlightening bit. HONESTLY at this point I had no idea what to expect and was beginning to wonder if this was all worth doing.
I took a typical USB mains charger and typical short black lead – and plugged it into my wife’s Samsung tablet. 550ma. I then took a fancy thin Chinese green lead – 600ma. I was expecting the opposite – that’s what I get for thinking – but we’re really not talking much difference.
Sticking with the green lead I then tried different plug-in-the-wall chargers. The second one I tried offered only 380ma – that means not far off TWICE the charging time (obviously – less current – longer to charge) – the Samsung charger my wife had been griping about – ZERO. That’s in the bin.
I then went on to try different chargers…
White Samsung Charger – ZERO
Black Samsung Charger – 500ma.
Black (small) ASUS charger = 600ma.
All-singing Sandstrom dual charger supposed to put out up to 2.1 amps – 350ma.
PC High Power USB 2.0 hub – 450ma.
As you can see – no apparent sense – why would the largest charger not put out the most charge? The little ASUS put out the most. Quite simply voltage – the nominal 5v of these devices has tolerance (variation) and the voltage will vary from unit to unit, manufacturer to manufacturer. So while there are limits to how much current a unit can deliver, if the voltage is too low – you are simply not going to get the current – results will vary from device to device.
So armed with the best charger (for this machine) – the ASUS – I went back to lead testing.
BOY that was an eye-opener – 600ma from my fancy green flat lead from China which I EXPECTED to perform poorly)– but a much shorter, white, very thin Apple-looking lead – 280ma – that’s well under HALF the charge rate and so TWICE the charging time for the white lead. How does this happen? Well, very THIN wires tend to drop voltage along their length. Some day I’ll make a super testing station with voltmeters all over the place – but suffice it to say that building this rig and testing combinations of your various USB chargers and leads WILL produce results!
I substituted the high power Samsung tablet for my smaller Nexus 7. Green lead 440ma, white lead 380ma – less marked as the current requirement for the Nexus is lower – but still quite significant in terms of charge time.
My Samsung S4 with extended battery – 550ma for the green lead, 270ma for the white lead – again – choosing the latter would potentially DOUBLE charging time.
Sticking with the S4 – I found an old HTC lead – looked a little thicker than normal – WOW – 720ma. The difference between the worst lead and the best – THREE TIMES.
Now there are lots of things that come into play here and I’ve not had time to do full tests but at least in theory you are talking the difference between a (say) 4-hour charge – and a 12-hour charge – which would you prefer?
So – what if you’re not a dab hand with a meter and razor blade. Well I can’t make any promises but there ARE amazing USB testers out there – some beauties – some with indicators – some with proper displays…
Cheap – so cheap don’t even think about it – just get it.. but it’s not all-singing and dancing…
Or if you want the all-singing impressive type even showing power (which is of course only current times voltage so you could get that from the cheaper ones)…
A tester that shows the voltage at the charger end – and the current running throughout – can tell you a lot about the charger ultimate capacity and the lead.
For my final test – on the Samsung tablet – I tested a VERY short USB lead – around 100mm long – don’t even know why I have it – guess what.. 1.3 AMPS – the difference between charging the Samsung with the WORST lead and the BEST – OVER FIVE TIMES.
Armed with my new short lead – I went back through the power supplies – sure enough – more current than before but still pretty awful – but for one black Samsung charger which now delivered to Maureen’s tablet over 1.7 AMPS – let’s have that in perspective – that is SIX times more charge than the worse case. Pretty damned worthwhile research if you ask me !!
Here’s my advice – buy a tester – get short, fat leads – pick the best charger. Simples.
I’m off to put some leads and chargers in the bin!