Browsing Posts published in October, 2010

Save Our Bees

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Save Our Bees!

Save Our Bees!

Save Our Bees!

Save Our Bees!

SAVE OUR BEES!

With the blessing of our neighbours, LEAF have recently given home to a family of bees on our Norwood site.  Beforehand, we liaised with our neighbours, fellow plot holders and the council’s Allotment Office.  They were unanimously in favour because we all know that bees mean…

better pollination of crops

which in turn means

a more plentiful harvest

However, it has come to light that a small but vocal minority are opposed to the bees remaining at LEAF.  We find this difficult to believe.  How could bees be anything but good?

REASONS TO SAVE OUR BEES

Bees need your support! The UK honey bee population is in decline and the British Beekeeper’s Association has stated that if positive action is not taken immediately, Britain’s honey bees will disappear by 2018!

Bees help make our food! 3 out of every 4 mouthfuls of food we eat are directly or indirectly the result of the work of bees.  Most food crops are pollinated by bees, and if the bees disappeared the crops would fail.  If this happened on a worldwide scale, the whole world would starve!

Bees keep Britain blooming! Bees pollinate the flowers in your garden, in the park, in wondow boxes -without the bees, the world would be a much less colourful place!

Bees are FASCINATING! This is a unique opportunity for local people to learn about bees and how they live.  If we don’t act now then the only way to learn about bees in the future may be in a museum.

WE NEED YOUR HELP!

We at LEAF believe that a world without bees would be a terrible place and that we should do all we can to help them.  If you agree to this, then please register your support by sending your details to bee@leafsheffield.org.uk – Thankyou!

(…Of course, your privacy matters to us, so we will under no circumstances pass on your details to a third party…)

And yet more problems.

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So, flushed with the success of getting my PIC programmer to work via the 5 pin ‘ICSP’ (In Circuit Serial Programming) pins and lead, yesterday I carried on with the code…

…And started to notice yet another problem.

It seemed that the circuit and code were unreliable.  I’d be sitting pedalling like crazy on the bike, when the PWM would stop working, making it exceedingly easy to pedal.  Luckily, I managed to catch myself before an expensive trip to the dentists was called for.  Unnerving, and certainly no good for anyone else to use.

I thought that the power supply lines going to the chips was ‘dirty’ with noise and spikes.  A reasonable assumption, I thought.  Sure enough, I checked with my new ‘scope, and saw that the lines were indeed dirty.  So, yet another trip down to Maplin’s  late yesterday afternoon to buy some ‘de-coupling’ capacitors, and on getting back and fitting them it did make a difference, but didn’t eliminate the problem entirely.

I then recalled my efforts with the little PIC16F684 and how it had been so well behaved.

Why? I asked myself.  Why, oh why, oh why…

And then I got the germ of an idea.  Maybe an inkling of one…

Going back to the original PIC16F684 programs, I went through them line by line, then went over the settings on the PicProg2009 assembler I use.

And I found it!  In the ‘configuration’ settings -the ones ‘hard-wired’ into the coding- I found discrepancies.  I won’t bore you with the details, but suffice to say that when I’d reset them -before I’d even got on the bike again, I knew I’d solved it.  A real “Whose Cat??!!” moment, you might say.

So, today I’ve been down to Maplin’s yet again to get the more bits that will enable me in the coming days to combine my circuit with the programmer.  I also bought another cheapo ‘scope probe so I can see two different points of the circuit at the same time.

Now with two traces.

Now with two traces.

If you look at the image to the right, ignoring my reflection, you can see the top trace with the ‘spikes’ in it.  This is the waveform going into the gates of all four of the FETs.  Remember that these FETs are in effect ‘active low’, so the time that each FET is ‘on’ is the flat part between the spikes.

The lower trace shows the voltage at the output of the FETs before any smoothing takes place.  The ‘double dip’ beneath the top spikes is the recovery diode kicking in to ‘dump’ current in the right direction from the inductor just ahead of it in the circuit.

So, now I’ve got those extra bits it will mean that when I’ve got the new circuit built, probably tomorrow afternoon, rather than having the computer plugged into the programmer which then plugs into my board, I will have a board (…soon to be in its own box!..) that plugs directly into the computer via a standard 9-pin serial lead.  This will then of course mean that I can plug the ‘new’ laptop into it as they did in the film ‘Aliens’.  Given some of the current ‘challenges’ we’re facing at this particular time (…See the ‘News’ heading very shortly…), I’m beginning to wish I had built a couple of ‘Remote Sentries’.

Oh, and given Sigourney Weaver a call.

Progress.

Just a few minutes ago marked a real ‘turning point’ in my endeavours with the bike charging circuit.

Now, given that Diane and I did so much shopping on Friday, and I can hear all those shiny brand-new parts calling to me (…I can hear them teasing me, and my fingers are itching!…), I could be ‘playing’ with them.  I could have got at least a couple of solar cells out on the balcony to see just what kind of outputs I could get -it is full sunshine after all.  Maybe a few years ago when I was younger and more ‘wet behind the ears’, I would have done.

But no!  I am now much stronger than that!

The PIC16F887 in place.

The PIC16F887 in place.

Instead, I’ve been working on the circuit and as I said at the start of this, I’ve so far made real, measurable progress.  A week last Wednesday the 6th, I told you of the ‘Big Boys’ moving in, namely the 40 pin 16F887’s I was planning to use.

Well, what I didn’t mention was that some time ago, my PIC programming board developed a very unusual fault in that it refused to program PICs in their target circuitboard as it should.  At the time, after only a cursory inspection, I decided to live with it and simply move the 14 pin 16F684 into the programming board each time I needed to program it.  A bit of a hassle, but one I could live with.  I would deal with it later.

Well, today, ‘later’ arrived with a bump.

Enter the big 40 pin ‘monster’ that is the 16F887, and I had a problem.  My programming board’s largest socket was only 28 pins.  The chip wouldn’t physically fit!

SO, I had to get the ‘in circuit programming’ working.  And this I have done!  Thanks to the magnifying glass I bought from Maplin’s the other day, I managed to track down a short across two tracks on my board that was completely invisible to the naked eye.

Furthermore, I have successfully ‘ported over’ the PIC16F684’s code to make it work on the 16F887.  I was using different port pins for different inputs and outputs, but the main parts of the code -the voltage sensing and the Pulse Width Modulation (PWM) work on the new chip with very few modifications.

Now, if you look closely at the above photo, you can just see four LEDs above the new chip -three greens and a single red.  My next task will be to get the circuit to accurately measure the voltage at the battery and give a ‘bar graph’ output on these four.

This’ll be fun!

More to follow…

More purchases.

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Yesterday, after she’d finished doing some ‘outreach’ work at a local school, Diane picked me up and we went off on a massive shopping spree.

From B&Q in Darnall, we bought two sets of low-voltage outdoor lighting, comprising four low-wattage lamps in each.  These are all 12 volts, so will ‘interface’ with our power system quite nicely.  They’re also low-power in that each lamp is only 20 Watts.  Now, 20 Watts from a ‘normal’ incandescent lamp is pretty dim, but in the 12 Volt dichroics that we use, pretty bright, and certainly a much better ‘colour’ of light.

This will give us a total of eight lamps with which to light our three gazebos a fortnight from tonight.  They’re special ‘rain-proof’ models that will hang quite nicely from just inside the tops of the gazebos, and I think they’ll look pretty good.

We also went to Bardwell’s on Abbeydale Road in Sheffield, the ‘Home of Electronics’.  There we purchased 12 solar panels.

These are smaller than the original ones planned, but this is no real bother, and it means they are small enough to move in and out of the sheds on sunny days.  This also means that we don’t need planning permission to mount them on the roof of either shed.  This will save us quite a lot of money in ‘planning permission’, and we’ve heard that the law may be changed pretty soon, meaning that we can mount them wherever we want, without fear of The Council’s ‘Big Fellas’ coming round, with grim, yet somehow ‘gleeful’ expressions on their faces.

So I’ve certainly got my work cut out, electronics and programming-wise!

I’ve now got to wire up the eight lamps with long cables and in-line switches with weather-proof plugs and sockets on them, then I’ve got to knock up another box for the second battery and electronics.

I’ve also got to re-design the boxes in that they will need plenty of flashing LED’s of various colours (…yes, blue will be in there…).  ‘Junior Plotters’ have requested this, and I think its a good idea.  Maybe not quite as many as the new ‘Enterprise’ (…Thats ‘Star Trek’ to the uninitiated…), but certainly along the same lines.  Oh, and the lights have to mean something, rather than just flashing at random.  Also, ‘Star Trek’-style touch-screens may be a little beyond this first demonstration, I feel.

We’ll see!

Joking aside though, I will put extra circuitry in the boxes to allow them to be plugged straight into the ‘new’ laptop to program them directly rather than having to keep taking them apart to get at the PIC processors.  It only needs five more transistors and a handful of diodes and resistors (…and an LED!..), and will make my job much easier.

It would look quite good on-site as well, being sat there with the boxes hooked up to the laptop, but maybe thats just the Big Kid in me wanting to ‘play’?!

Work continues apace.

This last couple of days, things have been pretty quiet on the ‘Power Front’ due to me attending the excellent ‘Beekeeping for Beginners’ course run by ‘Groundwork Sheffield’ (…see ‘Blog Entries’ for details…), but today I’m picking up the reins and carrying on from where I left off.

So, where do we stand at this moment?

As it stands, I’ve got two bikes modified in that they have the ‘slick’ back tires to reduce noise when pedaling.  I’ve also got two ‘A’ frames with motors (…generators…) attached which convert the pedaling into electricity.

I’ve also got one circuitboard that monitors the voltage/current being supplied and then ‘conditions’ this into a form suitable for the battery.

So, right now (…will, when I’ve done this, actually…) I can get on a bike and pedal and put charge back into the now-discharged battery.

Great!

However, for two weeks tomorrow and our ‘Halloween Bash’, I have to build up another power converter board then build boxes to house the pair of them safely so I can take them down to The Plots ready for the ‘Grand Showing’ of our new system.

At some point, probably this weekend, I’ll be going down to Wickes or B&Q with Diane to purchase the actual lighting required.  Then I’ll have to wire it all up with the correct connectors so that on the night, it’ll be a simple matter of unloading it all from the car and then plugging everything in.

Simple!

Oh, if only it were…

Buzzing. 15/10/10

Yesterday and Wednesday, myself, Matt and Diane went to a course called ‘An Introduction to Beekeeping’ run by Groundwork Sheffield as part of the ‘Bee Buddies’ program they are sponsoring. This was an effort to ‘get us up to speed’ with the new bees we now have on site down at LEAF.

And what fun it was!

I would never have guessed that there’s just so much to beekeeping!  You would think its just a matter of whacking a few hives in and leaving them to it.  Not so!

As previously mentioned, Jez will be visiting every week to tend to ‘our’ bees, and after the last two days of intensive training, I can fully see why!

In ‘The Olden Days’, before the spread of diseases, then yes, you could have just left them to it, but these days, what with the spreading of the varroa mite, and other equally nasty diseases, and in summer the threat of swarming, hives have to be checked on a very regular basis.

As part of our ‘allocation’ of six hives, five of them are ‘Nuc’ boxes (…which is actually pronounced ‘nuke’…), with the other being a fully functioning hive.

I won’t go into any detail whatsoever here for fear of either saying the wrong thing and showing my almost complete ingnorance, but if you’re interested (…and you should be!..), then I suggest you read up on bees.  All I will say is that they are (…to me at least…) totally fascinating and absorbing.

Other news was that last night was the monthly ‘management meeting’, and this went pretty well, though it was rather long.  Hopefully next time, it’ll be a lot shorter.

So, today will be a day of coding and ‘electrickery’ as I continue work on the Pedal Power Project.

More in the ‘Power’ Blog.

Sweaty!

Yesterday, after much messing around, I managed to safely discharge the car battery I’m using as a ‘test rig’.  In the end I used three 50 Watt 12 Volt dichroic lamps wired in parallel to give a total loading of 150 Watts.  -You know the little ones that have recently become so popular.

It took three hours to bring the battery down from 12.34 Volts at rest to 11.08 Volts just after I’d disconnected them.  This 11.08 Volts rose soon afterwards in the way that batteries partially ‘recover’ after a major discharge.

So, today’s task was to start recharging it!

Well, I’ve kept hopping on and off the bike to make adjustments to the code and various tweaks to the hardware, but I can safely say that I’ve done about an hour’s ‘hard’ cycling.  The kind of cycling where you end up very sweaty and the handlbars are wet when you get off.

Too much detail!

Anyway, I have to get a shower right now, then I’m off on a couple of errands -one of which being taking the faulty power supply back to our friends at Bardwells, then this evening, it’ll be back on the bike again.

And no doubt another shower afterwards!

The Great Day arrives!

We can finally reveal all.

All the secrecy, the hushed-up meetings, the furtive whispers behind closed doors.  All the knowing nods and winks and nudges are now over.

WE HAVE BEE HIVES!

Now, thanks to Anna and Jez from Groundwork Sheffield, and a huge amount of work done by Diane and our tireless volunteers, we have no less than six hives right down in the bottom of our Orchard Plot, well away from the road and possible encounters with pedestrians and passers-by.

Diane and Matt went on the ‘taster’ course last Thursday, and I will be accompanying them to the full two day course this Wednesday and Thursday over at Wood Lane Countryside Centre just up the road from Hillsborough.

Over recent times, we have ‘idly’ speculated during our tea breaks that wouldn’t it be great to have ‘a hive’ on our allotment?  It would guarantee that our crops were pollenated and we may even get the odd pot of honey, if the hive could spare it.

Well, a few months ago, we noticed in The Sheffield Star newspaper that the odd story kept surfacing about how British bees were in decline for a whole host of reasons and that The British Beekeeper’s Association were keen to promote a ‘whole new generation’ of beekeepers.

Part of this came Sheffield’s way in the form of ‘Bee Buddies’.  This is a ‘sponsored’ beekeeping program.

Eligible sites were sought around Sheffield and the owners or tenants of the sites were then offered free two hour ‘taster’ sessions as an introduction into the art of beekeeping then an intensive two-day course to reveal more of the secrets of the ‘craft’ of keeping bees.

Well, we had to sign up!

Fortunately, our site was pretty much ideal, and after a full site inspection, it was agreed that we should be one of the ‘chosen’ places.

One of the new hives.

One of the new hives.

Today, Jez brought six hives -five smaller ones and one larger one.  This photo shows one of the smaller ones ready to be placed on its crate before the bees were let out.

The hives in position, and the bees released.

The hives in position, and the bees released.

To the right here, you can see all six hives, the larger one being the one on the right of the picture.

Of course, when we’ve been on the full two day course, I’ll be able to tell you what they are called and what the differences between them are.

You can see in this photo the screening we installed yesterday evening in the background.  This serves two purposes.  Firstly to try to ‘steer’ the bees in the right direction and secondly to minimise any danger to the plot-holder who has the end plot beyond ours as this is the main pathway into his plot.

When Jez released all the entrances to the hives, he certainly showed a great turn of speed away from them!  Given that they had been ‘locked up’ in their hives then had quite a bumpy journey on the back of Jez’s trailer to get down to The Plots, we guess they were not too happy!

Close-up of the larger hive.

Close-up of the larger hive.

Here you can see a final shot of the larger hive with the ‘front door’ open.

As you can imagine, this shot was taken with the zoom on my camera set to ‘maximum’!

Jez will be returning tonight, this time wearing the full bee-proof suit to fully inspect the hives and to make sure that everything has gone according to plan.

As I previously mentioned, he’ll be coming by once a week now for the full year to fully check and monitor their progress.

Anyway, I’d better ‘buzz’ off.  I’m seeing just how long it takes to nearly flatten a car battery with 150 Watts worth of 12 volt lamps.

(…Sorry!  I just had to get just the one bee joke in there.  I’d been buzzting a gut trying to keep them all in…)

Whoooops #2.

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Well, not really a “Whoooops”.  More of an, “Errr.  How on earth do I get rid of that lot?

My problem Dear Reader, is that I’ve fully charged the test battery with one of the electric bicycle generators.

It is completely, utterly full, according to my multimeter.

…So how do I discharge it, and more importantly, how do I do it safely?

Well, the only thing I can think of right now is to wire up some 12 volt lighting and leave it on.

Then, there’s the problem in that even running four 50 Watt lamps off this thing at full whack, its going to take a little over three hours to make a dent in the battery.

Another problem is that by having these lamps on for three hours, I’m going to light up my flat like Wembley Stadium.

Let’s just hope the police helicopter isn’t flying tonight, or he may mistake my flat for his landing pad.

But on second thoughts, I think I’d best leave it while tomorrow and daylight.

Sunday Plotting. 10/10/10

Last Thursday, I hinted that Matt and Diane were up to something secret.  Something I couldn’t tell you about.

Well I still can’t.  Not ’til tomorrow after 9.00am! continue reading…


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