The Puffer Forum

Okay, I tell ya the truth JHong, if it wasn't for your awesome style of writing I'd have cried off quite a while back... but I'm holding in there!

This is all gonna be on a circuit board or something isn't it, nice and compact and simple looking...

I'm definately not understanding what the 0V part is though, zero volts? And what do you mean by "Of course, all the "0V" connect together" but I have a feeling this is all gonna make a whole lot of sense when we see the actual pictures of the actual parts. I've seen the simple circuit boards my friends in tech college made, and it was amazing what they could do with a handful of simple looking parts, just like this!

Waiting.. waiting... this is going to be an awesome addition to my new 75 gallon tank I'm working on (pair of jack depmseys, the electric blue variety).

Myaj wrote:
I'm definately not understanding what the 0V part is though, zero volts? And what do you mean by "Of course, all the "0V" connect together"

Oh right... normally in circuit diagrams, you don't draw lines connecting all the parts at the same potential together. Then you can split things up into smaller blocks. For example, anything that takes 5V, I could just put an up-arrow and write "5V". I've drawn the connections in in this case though. Similarly for +12V. Of course, a power supply dosn't just have a +V lead, its also got a "negative" (AKA ground, or "0V") lead. There would be too many lines if I connected all the "0V" parts together, so I just use an earth symbol and put 0V. But, in the circuit, all these parts are connected together, and lead to the "negative" terminal of the power supply.

As for simple circuit boards -- yeah, I love them. Too expensive though half the time. We can get it down fairly simply onto prototyping board very cheaply. I'm trying to map out the layout as we speak.

j

Ready for more? (groooooaaaannnnnnn)


Here are the parts we're gonna use:




See, I told you they were small! The board at the bottom with the copper tracks is what we're going to use to construct our circuit on. Using this makes life eeeaasy .... it holds the components in place, and already has horizontal wires linking things across the board.

The board is called "stripboard", or sometimes :Veroboard", or "prototyping board with strips", and should be available from just about any electronics vendor.

Here are the components in detail.. This should help visualise the abstract symbols on the circuit diagram:



Regulator: a 78L05 low power linear regulator

C1: a 100 microFarad (uF), 50V aluminium electrolytic capacitor (25V is also OK, but I prefer the extra margin myself)

C2: a 10uF, 50V aluminium electrolytic capacitor

C3: a 0.1uF ceramic capacitor

MCU: Microchip PIC 16F628A (the standard 16F628 is also fine... no differences as far as we are concerned), in a standard DIP package

Socket: A 19-pin socket to hold the MCU so we can easily remove and lose it. Sorry, I mean program it.

XTAL: A 20.000 MHz crystal

C4&C5: ceramic capacitors.. anything between 15 picofarads (pF) and 30 picofarads is fine

R2: 1 kilohm, 1/4 W resistor. The exact value of this resistor will vary, depending on the number of LEDs you have in the moonlights. 1k is a fairly safe middle ground.... but do ask if you plan to make a moonlight with more than 6 or so LEDs.

Transistor: A BC337-40 NPN transistor

Drooooooooooooooollllll..... ComPONents.....

Yikes, sorry, I don't know where that came from.

Just a note before we begin building, if you or a friend have a multimeter (or even just a voltmeter) available, it would be very helpful. Not absolutely necessary, but it really helps to track down problems.

A solderless "breadboard", which allows you to test out your circuit first without having to break out the soldering iron, is also quite helpful. Unfortunately, despite the name, you can't eat it. Trust me, I've tried.

Here's my breadboard and multimeter, testing out the circuit we're about to build....



Again, this stuff is not strictly necessary, but if you have a friend of a friend that has them, then it'd be a good idea to get your hands on them (the stuff, not the friend. Well, unless they're cute/handsome. Or something.)

Multimeters also come with cool belt clips, which means you can strut your stuff down the street touting your Mad Electronix Skillz. (Just don't call me when you get roughed up).

Ready for BUILDIN'

This guide is sexy-hot. I dropped out of electrical engineering because the profs didn't do this enough! lol

Thanks!

The instructions for the build will be along tonight... once I've had a chance to do it myself

After the next instalment, I'm going to change the pace a bit. Y'see, by the time you've put together this first step, reading the circuit and soldering onto the board should become easier. Plus, we can't have this thread turn to 500 pages before we get finished.
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But JUST ONE MORE THING before we break out the soldering irons. Something I was planning to gloss over until we had the circuit built.

I was going to tell you, I promise.

I think it would be best to get this over and done with here though.

See our MCU in the pretty circuit diagram I posted? Behold the power! Stand and stare in awe at its beauty!

OK, ok.. enough of that. Well you see, this awesome little chip ain't gonna do much unless we tell it what to do. Connect up that circuit and... nothing will happen.

The MCU, as bright as it is, doesn't know we've got a moonlight connected to it. And if it did, it'd have a hard time guessing what we wanted to do with it.

So, we need to tell it what to do.

For this, I recommend my wife. She's very good at telling things what to do. If you situate her in the same room as the MCU, and then.....

Only kidding. Well, half. But it's irrelevant, as I won't lend you my wife.

We need to have a way to write short programs on our computer (we all have one of them, right?) and then download them onto our MCU.

No! Stop! Take that chip out of your floppy drive... that's not going to work!

We need a programmer. One that is designed to program PIC chips.

They come in all shapes and sizes and price points. If you rush off now and do a search for PIC programmers, you'll likely be aghast that the only ones you can find are quite expensive. But not to worry -- they can be had cheaply. I won't recommend a particular model, but briefly list the things to consider:

• - Does the programmer support our chip? Most will, but some of the very old ones might not.
  
  - Does the programmer plug in via USB or an old serial port? Not all new computers have serial ports, and for ease of use, I recommend USB... but serial port programmers are more established and possibly cheaper.
  
  - Does the programmer require an external power supply? Most USB ones don't, but you should check. The power supply requirements can be quite odd (like, say, a 16V supply).
  
  - Does it come in kit form or assembled. Kits are cool – easy to assemble with the instructions provided (and a soldering iron), and can be cheaper.
  
  - Do they come with a ZIF socket? These sockets make it easy to insert and remove your chip into the programmer. Some kits don't come with a ZIF socket, to reduce cost. Make sure you order one separately.
  
  - What is the programming software they use? Is it easy to use? (snazzy professional units use the official "MPLAB" software from Microchip... but I find this quite cumbersome to use) [Note: the programming software varies depending on the programmer, but it is usually given away or downloadable for free]

What do I use? I use the "DIY Kit 128" from http://www.kitsrus.com . You will see these sold around the web as kits or fully assembled, at various price points and with different names, but they are all easy to spot. They are USB, and don't need a separate power supply. Their price ranges from $40 - $60.

If I was buying again, would I buy the same? Yes, possibly.... but I would look on eBay. There are many new PIC programmers on eBay. It'd be foolhardy for me to recommend any particular sellers to you, but the following promising looking programmers came up in a "Buy it now" search for "PIC programmer":

This one looks like it'll do the job at only $12.95!!!

This one is really fancy – will program everything, even your dog. Can’t vouch for ease of use though. $23.

Here's one similar to mine. Serial and USB. Easy to use. $39

Same again. $38

Same. $35

And many, many, many more. Of course, the usual caveats apply for eBay – check the seller's rating, the delivery fees, and feedback... and ask questions if you feel uncomfortable. But, in my experience, it is absolutely the best place to pick up stuff like this.

OK, OK.... I can afford that.... but what about the programming? It sounds far to complicated for me or my odourful Aunt??

I'd better explain a bit. You see, the MCU takes its instructions in machine code. Machine code is like looking at those green symbols in The Matrix. Trippy, but not good if you want to get stuff done.

So, our friends at Microchip created a low-level "language" called Assembly language, or "Assembler", that allows you to write in vaguely meaningful codes, and translate it into machine code when you're finished. Now, there are loads of geeks in the world who love Assembler. Not least, beacue it is free.

I, for one, can't bear it.

You see, in Assembler, you can't give a chip an instruction like: Nooooo... no way. In Assembler, it would look something like this:
AAARRRRGGGGHHHHHH. If you hate your life, then take my advice: Program in assembler. It is very powerful, but only if you have the time.

But WAIT.... Don't worry.. there are other options. You see, there are more "high level languages", which take in instructions like "Walk from A to B", and translate (or "compile") it into instructions that our MCU can understand.

That's what we're going to use. Phew.

The kicker? This software can be expensive. My tool of choice would be PICBASIC PRO. Based on the popular BASIC language. It can be yours for $250.

YIKES!!! NOT **** LIKELY... NOT FOR SOME STINKING MOONLIGHTS!!!

OK, OK, calm down... don't worry. There is another option. There is a lesser known competing product called MikroBasic. Straight from Belgrade. Really. This software is ABSOLUTELY FREE, provided your final programs (after conversion into MCU language) take up less than 2,000 program words. This should be fine for us. And if we do run over (unlikely), it doesn't matter, as I can attach the compiled code for loading onto people's chips.

THIS STILL SOUNDS FAR TOO COMPLICATED

Trust me -- it's not. I post the code. You copy and paste into MikroBasic. Get MikroBasic to compile it into machine code and download it to your chip. I'll try to include comments in the code so it's easy to understand what's going on... but if you're not interested in any of that, it really is just a copy - paste job. I learned how to code by starting out copying other people's code.

Still not up for it? A friend with a programmer could program the chips for you with the code I post... or, I could even send you a pre-programmed chip (if you cover my costs).

A few dollars and a bit of time is a small investment to make for this though. These tools open up a world of possibilities. From flashing Christmas lights to full-on aquarium water changes.... you'll be able to do it, and quite simply.

***** IN THE NEXT POST I REALLY, REALLY, REALLY WILL BUILD IT. HONESTLY. IT'S ALL DOWNHILL NOW. ********

Hmmm... Gotta buy more toys, er, I mean computer hardware before I can build this project? (Pretending he didn't see that coming...)

As if you needed an excuse to buy more toys!

Seriously though, for $12, it's hard to go wrong!

Enuff of all these words!! Ready for BUILDING?????

First, take out the stripboard. You'll see that one side has copper strips, and the other side doesn't. The side with the copper strips is the BOTTOM. We put our components on top, poke the legs through and solder the to the strips on the bottom.

Easy.

First things first though, we need to cut the board down to size. No, not by throwing insults at it...

We need an area 30 holes wide and 20 strips high. Cut one hole/strip outside this to give a bit of excess area. We're looking for a board like this:



You can cut it carefully with a hacksaw if you like. Actually, you could use an axe for all I care.... however, I prefer scoring it several times with a scoring tool, or a craft knife. Then, when you’re almost through, you can snap it along the groove. Be careful, as they do have a tendency to shatter and generally be incredibly irritating.

If you want to draw on lines where to break it, then do it on the yellow side, NOT the copper side!

Here's what I did:

Mark out...


Score...


Snap!... (be careful not to pull tracks off the board!)


Here is the layout for the board:

This is looking from the top, with all the components in place:



See the pretty pink crosses? That is where we have to break the coper tracks on the bottom.

Turn the board over, and break the tracks. It’s easiest to break them around a hole with an old drill bit – just hold the drill bit (NOT IN THE DRILL, SILLY ), over the hole and twist it until it scratches away the copper track. Like so:




Remember (DUH) that when you're looking at the board from the underside, right becomes left and left becomes right. So, looking from the bottom, the track breaks will be in these locations:



Be careful - it is hard to re-join the tracks if you mess it up!

Done!

The next step is important. We need to clean off all the grease that got on the copper from our hands. That's right, you dirty, dirty fishkeepers . Solder won’t stick to grease, and you’ll just make a mess, and destroy the board. Rubbing alcohol works fine for this... or, in a pinch, washing up liquid or soap and water. Clean all the grease off and dry the board thoroughly with paper towel.

Now, it's time to solder the components on. You can poke the leads through the holes (Making sure you connect the regulator, C1, C2 & the transistor the right way round!), then turn the board over and quickly solder the leads to the copper strips. Then, when the solder has cooled, snip off the excess leads on the bottom.

Here I am soldering on the first capacitor:





Easy.

You can solder the components in any order you like, but be aware of the following:

C1 and C2 MUST be connected the right way round! They will have "-" marked on their bodies to indicate the negative lead. The positive lead should also be longer.

The regulator MUST be connected the right way round - as shown in the diagram. Input to the top, output to the bottom.

The transistor MUST be connected the right way round, as shown in the diagram - Collector to the bottom, Emitter to the top.

You can use any old pieces of wire for the wire links. I use tinned copper wire, but anything will do - even bits of wire nicked from an old network cable!

The crystal and transistor are the most sensitive components -- do them last, and try to solder them on quickly.

The very last thing you solder on should be the wires leading to the PSU and the Moonlights.

Don't plug in the MCU until we're totally finished!... just solder in the socket!!!

All the components, before adding the off-board wires:



And Finally... Finished:





Woohoo!!!!!!!

Now, before we can do anything, we need to check everything carefully. Make sure you haven’t accidentally joined adjacent tracks together with solder. Check also that none of the component leads are touching each other - especially around the crystal. If you or a friend have a multimeter, it is a useful tool to check the resistance between adjacent tracks.

I always manage to join some together with tiny bits of solder, by accident. Check CAREFULLY for any joins and clean them up by quickly running the soldering iron between the tracks.

The next step is to test that everything’s OK. The first lesson you learn in electronics: Things NEVER work right first time! Seriously! But problems can always be solved.

DO NOT plug in the MCU yet!

You really need a voltmeter (multimeter) for the next step... If you don’t have one, don’t worry, you can skip it... but it will be much harder to see what's happenning if something is going wrong.

If you have a voltmeter, then do these tests.....
_____________________________________________________
Briefly plug in the circuit, and check that you can see 12V on the input side of the regulator, and 5V on the output.

Follow the +5V and 0V wires through the circuit and find where they meet the MCU socket (the middle pins). Check tha the voltage here is 5V. Check that all the other pins see 0V.

All OK? Done. Not OK? No worries, it happens to the best of us. Time to go back and triple-check everything.
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A note here: If you turn on the power something seems “wrong� – i.e. you hear hissing or crackling, smell burning, somthing seems odd, or you can find unexpected voltages in places there shouldn't be, then TURN THE THING OFF... **DON'T** try to sniff out the source, or put your face close to the components. Those capacitors can and will go POP, and you don’t want that happening in your face. Trust me, it's happenned to me (and I jumped into the air like the big wuss I am).

Keep your distance. If something doesn’t work, UNPLUG the circuit and locate a hot component by gingerly touching each one on turn (bearing in mind a blown component could be hot enough to burn you).

This would be a great time to point out the following....

READ THIS - JHONG wrote:An obligatory note: Things here should be fairly safe... BUT, I am in no way responsible for you burning or electrocuting yourself or anyone else. You put together this project entirely at your own risk, and I can not and will not be held liable for any damage that arises from following or not following my instructions.

I am no gospel on electronics (far from it in fact) - just a fellow hobbyist relating stuff I've picked up through experience. This is a fish forum for sharing information. Treat everything I say with a healthy dose of skepticism.

0-0) 0-0) 0-0) 0-0) 0-0) 0-0) 0-0) 0-0) 0-0) 0-0) 0-0) 0-0) 0-0)

Yawn... enough of that... all OK? Just sign your rights away on this dotted line, and we'll be moving right along....



In this project, we've reached the crest of the hill -- it's all downhill now. In future installments, I'll show you the plans, but if you've got this far, then there should be no more need for walkthroughs.


What the HE**???? You just broke my moonlights! The circuit does nothing!!!

Aargh, you noticed.

Well, we still have to program the chip before it'll do anything.

Here's a sneak preview of what it will look like once programmed:




But to do it, you'll have to WATCH THIS SPACE!!!!

Where's everyone else gone? Helloooooo! (echo)

Sorry for the long posts! (echo)

Wooooooo! (echo)

well seems the majority of folks are either dead or scared. you should fix that disclaimer

seriously though i think they are buying parts. should be back later.

Those lights are bright!

Very cool thread; I'll be wiring up some LEDs and resistors this weekend.

Have you experimented with red LEDs at all?

Left everything electronics-wise back at home whilst I am at university. Commiting this to memory. Hit me. I want more. I want it all.