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bazobeleza

bazobeleza

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There that got your attention!

As it seems a day for electronic and computer based posts I add my I own query.

Are there any amateur programmers or electronic wizzkids with a knowledge/experience of Pic programming.

The scenario is this:- automatic sound generators cost a small fortune. I believe from what I have read, that Pic Chips can be programmed to perform simple control tasks, they use them in schools when teaching third year science. The control task is quite simple, on for x seconds of for x seconds on for x seconds off for x seconds, start again. ( a cuddly toy if you can recognise the colregs sound signal from that)

If a Pic chip can drive a relay then and be programmed to do a dozen similar tasks then we have the makings of an auto foghorn system.

Are there any science teachers, programmers, or just plain computer geeks out there that can give me a hand with this project? PM if you can
 
Hmmmm the standard horizon DSC VHF does this all by itself, just dial up sail, motor etcccc and it'll make the right honk through the speaker/tanoy if attached
 
Pics are a wide range of microcontrollers that can be programmed using a very obscure system. What I think is used widely in schools and sounds just the thing for your project is a Picaxe .

This is a system that uses a limited range of Pic chips with Basic programming. It was originally designed for school teaching so it's fairly simple and the parts are quite cheap. I have found it a very straightforward way to solve a number of tasks. As well as detailed manuals (there are 3 and you need to read quite a lot of at least the first to get started) there's a very helpful User Forum .

(I think there are other products approaching the same type of problem but this is the only one I know about in detail.)

Let me know if you want more advice; I don't know all there is to know about these but, not being a computing/electrics professional, I can understand the problems.

Derek
 
I speak a bit of PIC (16F84), but I'm not sure it's the best way of solving your problem. How are you on assembly language programming? You'll also need an amplifier & some sort of speakers (weatherproof).

If you're planning on making a fog horn, bear in mind that it should satisfy the requirements of Annexe III of the ColRegs, and that:

The construction of sound signal appliances, their performance and their installation on board the vessel shall be to the satisfaction of the appropriate authority of the State whose flag the vessel is entitled to fly.

Now I will admit to using a non compliant frying-pan as a 'gong' (I think my wooden spoon 'striker' is less than 3% of the weight of the pan).

I await the tirade of righteous indignation on the folly of choosing to 're-interpret' the ColRegs /forums/images/graemlins/smile.gif

Annexe III

Andy
 
I've developed commercial hardware for the refrigerated transport industry using PIC16C74 chips. Full on radio networking, temperature recording, position reporting stuff. They're very very powerful, reliable and cheap!

As you say, hook up the output to drive a transistor to drive a relay, which could then be linked to a horn sounder.

You need to buy one of the UV erasable, or electronically erasable chips to develop with, and some breadboard. You'll need the progammer device also.

Reckon you could have all the kit you need to develop a prototype for about £100 to £200... less if you buy off ebay second hand.

Nice idea.
 
A pic will do it. You can get development kits from Farnell. There are plenty of other 8-bit microcontrollers that will also do it, but PIC is well known and well supported, so a good choice.

However, if you want to generate timed pulses with lengths in the order of seconds, then this could probably be done using analogue timer circuits. I'm sure there are some devices, such as 555 timers, or using RC constant and comparaters, that will do the job. To use a PIC is probably over engineering it.
 
Agreed it's over-engineered, but it's a tough call to design a circuit that at the push of various buttons will pause for 60 or 120 seconds, and then once that pause is completed, it then switches the horn on for some number of repetitions with some _other_ pause/on period and count.

Once you have the PIC development kit you can churn out all sorts of electronic projects for all sorts of things.

Oh, for instance, the 16C74s have multiple analogue to digital converters onboard. You could quite feasibly create a single box of tricks that will not only do all of your fog horn blastings, but also record engine temperature and give alerts above certain values, and also hook it up to a bilge water detector... etc etc. They're really versatile.
 
I have used the 8031/8052 micro controller that and most you program in assembler. The 8052 you can program in BASIC so my be easer.

PLASTIMO do a complete automatic fog horn as you describe here

In an old catalogue (2005) they also had just the control but not found by google yet.

Also look here

Best Electrical Engineering Application
£550 prize
Martin Spencer (17) of Heaton Manor School, Newcastle Upon Tyne
Project: Automatic Foghorn Timer
An automatic electronic foghorn which uses a PIC chip to store and activate the programmes to sound the set patterns required by maritime law.
 
I would use a PLC like this which can be programmed with a laptop (at least they could 10 years ago when I last used them) and made to do pretty much anything you want. Admittedly this one is 240v but I bet you could find a 12v version. They can be programmed by anyone with half an idea about logic and are bullet-proof. I'm not sure how much a pic costs (or even what one is!) but these things are great. I used to use Mitsubishi ones to control factory equipment and if I can do it...
 
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I would use a PLC like this ... I'm not sure how much a pic costs (or even what one is!) ...

[/ QUOTE ]

This is a pic of a PIC /forums/images/graemlins/smile.gif
image001.jpg


They're about 3 quid each for a basic one with 16 IO ports, but you can get them with built in comms, A->D and D->A converters & all sorts for a bit more. This one has eeprom memory, and can be programmed from a PC with a £30 programmer (DIY from your junk box). Needs a few capacitors and a crystal and you've got the equivalent of a Commodore PET on a chip. Tremendously versatile. Programming tools & assembler supplied free by Arizona Microchip.

The analogue route crossed my mind, too, but it would be cheaper and easier using one of these - especially if you want to choose different sounds.

The challenge is to find a suitable sounder or speaker at a reasonable price, bearing in mind it's supposed to be omnidirectional.

Andy
 
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