Basic Stamp Programmer

[Gambit22]

Bill, with a Stamp, you have to add the same extra components to drive a solenoid valve.

And nothing's easier than making PCBs using the photoscopic method. I invested about $10 in the chemicals and transparencies and that's it!

[billmi]

Originally posted by Gambit22
Bill, with a Stamp, you have to add the same extra components to drive a solenoid valve.

Exactly, and you need to add them to something - the BOARD. Until you do that, you're comparing a component to a system. It's like saying a VolksWagon is no good, because it costs more and is bulkier than a VolksWagon engine which has all the horsepower you'd get in that VW. It neglects the fact that you have to build a chassis and support hardware to use the engine. Not to mention that amongst the people who have the skills to use the finished car, not all have the skills to build the chassis. For those that do have the skills to build a chassis, it may be a very easy task that seems almost inconsequential.

And nothing's easier than making PCBs using the photoscopic method. I invested about $10 in the chemicals and transparencies and that's it!

What is the photoscopic method? Is it different than standard photo resist etching? I've known quite a few folks (when in college I worked with a number of EE and ME majors) who were very tecnically oriented, but made some pretty poor quality PCBs, despite having very nice equipment and supplies at their disposal.

Then of course it's back to the target audience of that series of articles - an airsmith that has done little to no electronics work before. What's simipler for that person, tacking a single interface component (a MOSFET or a resistor) to a complete board computer, and wiring that to a switch or solenoid, or designing a board computer printed circuit, etching the board, installing it's components, and the interface component and wiring it. For you, there may be nothing simpler than designing and etching the board. I know a few people who've discussed the articles with me for whom that is too complex, but adding a component to the stamp and programming it was do-able for them. I also have gotten feedback from folks for whom even that is too complex. You have to remember, not all of the world is as skilled and intelligent as you are.

See you on the field,
-Bill Mills

[Gambit22]

You can bend the pins of a PIC outwards in the same fashion and attach the external components in the same way. No, we are not comparing apples and oranges here. The PIC is designed to be an independent active electronic component, and so is the Stamp. There are no real differences between the two except the company, Parallax makes their product sound easier to use, when Microchip has their infosheets geared for an expert.
Parallax isn't even denying it, they use PICs in their Stamp.
Here's the schematic:

http://www.parallaxinc.com/downloads/Documentation/Basic%20Stamps/BS2IC_RevF.PDF

And what do you see on the "board"? a PIC, a crystal, an EEPROM, and a voltage reg. Pick the right PIC(no pun intended) and all you will need will be the voltage reg, and you can even make do with a zener diode!

Furthermore, "tacking on" components to the Stamp, isn't exactly the most reliable method of attaching a component, I already said that it can be done with a PIC if you bend the pins outward, but quality-wise it'd be better to make a PCB.

Which brings me to my last point. You need to make a PCB even if you're using a Stamp, where to place the MOSFET, the voltage reg and other things, because attaching them directly via solder won't last long.

Yes, the photoresist is a better word to use, photoscopic method is what the industry uses with fancy machines.

In reality, working with PICs is a lot easier than most people imagine, the key is not to be intimidated by them.

[314159]

i feel kinda bad about taking a cheap shot at bill's programming, i feel a little bad about it now, and i am sorry. i met bill at the doughnut orgy, and he is a pretty nice guy. well there is more than one way to skin a cat, i just like the pic method. there is nothing wrong with the basic stamp, but giving the picmicro a try might make a nice next step .

[JT2002]

wow, ,is seems complex, any suggestion to getting started, im 14 and very interested in messing around building boards for pb guns, any suggestions for getting started are greatly appreciated,
thanks, JT

[Gambit22]

You need to know at least basic electronics. Find a book on that.

[billmi]

314159,
No worries, I didn't see it as a cheap shot at me (or even a cheap shot, for that matter, you were just talking about drawbacks of using a Stamp as a solution). Certainly the limitations of timing delays to the millisecond isn't my fault, I didn't write PBASIC :-) and unless you were familiar with PBASIC, I certainly wouldn't expect you to know the capabilities of the BUTTON command.

I couldn't agree with you more on it being good to learn about how to use PICs. As I'd said before, the Stamp is not well suited for production, use, and not as flexible or capable of as much computing power as designing a custom app circuit using a PIC.

JT2002 - take a peek at these articles:

http://www.warpig.com/paintball/technical/electronics/basic_electronics/index.shtml

http://www.warpig.com/paintball/technical/electronics/solder/index.shtml

http://www.warpig.com/paintball/technical/electronics/basic_stamp/index.shtml

Don't expect to be an electrical engineer after reading them, but I have gotten a few e-mails from people with little to no electronics experience who were able to build Basic Stamp based paintgun control boards after these articles.

Also, I have found this book somewhat handy:

http://www.amazon.com/exec/obidos/ASIN/0830642005/qid=1013444544/sr=8-1/ref=sr_8_7_1/002-0997122-6642417

It has its downfalls (typos, mainly) but at least for me, it has quite understandable explanations of electronic theory and components.

See you on the field,
-Bill Mills

[ShooterJM]

Originally posted by billmi


The Centerflag fram (and I assume Booyah as well) uses the stock sear.

See you on the field,
-Bill Mills

Yeah they replace the on/off don't they? Otherwise the solenoid provided can't acutate the sear, too much pressure. Think I'm personally going to go with the Retro on/off pin.

[billmi]

The Centerflag grip frame uses the standard on/off as well. If it doesn't fit properly, they customize the length ot the on/off pin to compensate.

See you on the field,
-Bill Mills

[ShooterJM]

Originally posted by billmi
The Centerflag grip frame uses the standard on/off as well. If it doesn't fit properly, they customize the length ot the on/off pin to compensate.

See you on the field,
-Bill Mills

huh. wonder how they get enough force from a 9 volt soleniod to do that?

[billmi]

Originally posted by ShooterJM


huh. wonder how they get enough force from a 9 volt soleniod to do that?

There's a big fat capacitor inside the grip. I believe they are charging it, and then punching the solenoid with that charge. Theoretically you could even use a cap to capture the charge kicked back out of the solenoid when the field collapses (oddly enoug when you stop putting current into a coil the field colapses, and that generates a small amount of opposing current) and "recycle" it with the next shot, extending battery life.

See you on the field,
-Bill Mills

[ShooterJM]

I was not aware of that. Actually in this whole "make my own electro mag" process I keep encountering things that I hadn't thought of or didn't know!

[billmi]

Yep, going from idea to implimentation is a lot more complex than most folks realize. There are a lot of folks online who have "invented a new gun," but very few who have actually built one.

It takes a fair amount of mechanical energy to do the job of tripping the sear. Not only is Centerflag pulling whatever trick they are pulling (hey, it's that whole hooker analogy again) with the capacitor to just get enough power out of the 9v to trip the sear, but the front and rear movement requirements of the sear are *real* close to the travel limits of that solenoid. AGD went another route - they went with a beefier solenoid that that offers more travel than required to trip the sear, and a much larger power supply (battery) both in terms of voltage and amperage (9v batteries deliver relatively low amperage compared to other batteries, even an AA). Centerflag's aproach means tighter tolerances, and thus a higher chance that something can be out of spec and cause a failure. The payoff they get for taking that higher chance is a more compact and elegant physical package (due to the smaller solenoid and battery).

Another approach you might consider, is using a very small ram to trip the sear, and tripping that ram with low pressure air from an LPR like the Palmer Rock (or a Rainmaker LPR - they are VERY small, and could be mounted on a flat milled into an gas thru foregrip), controlled by a small solenoid valve (Humphries makes some nice valves smaller than Macs) that is controlled by the electronics.

See you on the field,
-Bill Mills

[ShooterJM]

Yeah, I've thought about that. The thing is I know I'm making some simple, stupid mistake somewhere. I'm running 14.4V 26AWG pull tubular solenoid. At pulses it should have enough to actuate the sear. Especially at the distances it needs to move. I have a few more adjustments to make and hopefully it'll work.

And to think this whole project started just because I wanted to try an idea for an electronic trigger. I should have just bought a cheap electronic gun to hack.