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Re: [LUG] OT PIC examples/lessons

 

Tom

Interesting. With the comparators you will be able to make a zero crossing 
detector, to sync with the mains, perhaps using an opto isolator, across a 
diode bridge? You could get it to generate an interrupt you. The PWM shouldn't 
be a problem. The timers will do that for you.

I'm not sure about grid connected though. I've always wondered how you do 
that. Any pointers?

Are you planning on feeding some form of renewable energy (solar perhaps?) 
back onto the grid?

The thing that always struck me about PV solar is that is generates DC. If you 
convert that to AC with an inverter you take an efficiency hit, which results in 
much of the power being lost. If you are powering electrical kit, it often 
converts the AC back to DC, with another conversion hit. Chances are you are 
throwing away half of that expensive solar power in conversion costs.

What we really need is a good DC-DC converter, with a number of outputs to 
power the various appliances directly (the server, monitor, ADSL modem, switch 
etc.). Make it smart enough to be able to power things down, and preferably 
monitor the consumption too. That would be a very useful bit of kit. It would 
need to be combined with a battery charger and UPS.

I was toying with the idea of a movable solar panel, or perhaps using a few 
movable mirrors to get more out of a panel by multiplying the incident light, 
and controlling it all with a small micro controller. I did a bit of motor 
control stuff for it with a GumStix. Wrote a driver for it. But GumStix are 
expensive, and over the top for this application, so if you want to keep costs 
right down, a PIC is a good choice. I always fall down on the mechanical stuff. 
I don't have the skills.

The machine code for the PIC is a bit odd, but nothing clever about it. Very 
straightforward. It will be just like machine code was 20 years ago! Have fun. 
Keep us posted.

D

> I've got a pickit 2 with a pic16f690 in it and some simple stuff
> I found this
> http://www.usna.edu/EE/ee461/Homework/Lesson12Spring2007PIC16Programming.pd
>f which sort of starts things off a bit.
> Its 20 years since I did machine code and I'm a touch rusty and theres not
> a lot of stuff to learn (plagiarise) from without going on a course. I'm
> trying to see if I can knock together a grid connected inverter for what I
> feel it should cost - naff all!
> The chip that comes with the pickcit2 looks like it should be up for making
> a controllable PWM+ sine generator for the inverter part so thats 0.5kva
> units at £50 each. I've nearly got that worked out but not sure of the
> code.... Then it needs a controller/monitor to sync with the mains and do
> simple control within whatever the 'legal' requirements are - cost £90 for
> the pdf! Tom te tom te tom
>
On Thursday 04 December 2008 21:37:15 Tom Potts wrote:
> On Thursday 04 December 2008 08:50, Robin Cornelius wrote:
> > Tom Potts wrote:
> > > Does anyone know of any PIC16 lesson/examples online at all?
> > > Tom te tom te tom
> >
> > Check out microchip's website, there is usually a handful of samples
> > when you drill down to an individual processor and in the processors
> > manual from that site there is usually snippets of code.
> >
> > Are you working in PIC's asm or have you got a C compiler going for your
> > pic?
>


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