PIC/ Hobby electronics forums

[dseaver]

Does anyone know of any helpful forums for beginners getting into hobbyist electronics or am I already in the right place? The project I am looking trying to accomplish is a way to control a set of sprinkler valves using the serial (RS232..i think) port on a pc. The valve use the standard 24VAC. I plan to design the interface myself for the most part, but i picture myself running into a number of roadblocks. Thanks!

 

[richs]

Hiya-

Although this forum is geared to practicing engineers, well, it's *NOT* geared for students (we spent too much time doing their homework for them), I can point you to a site or two that might prove interesting.

One is:

http://www.winpicprog.co.uk/pic_tutorial.htm

Although the PIC's used are a little dated, it does give one a head start and it's the one that I used a few years ago. Rather than using the strip PC method that he uses, I suggest going with one of those little push in breadboards where you can stick IC's and wires between them without resorting to soldering them. I also suggest that you start off with DIP IC's rather than surface mount.

There are some programmable PIC controllers out there that use the parallel port for programming. These can be problematic. You could look for the Wisp programmer which I think is sold rather cheaply, and there are certianly others.

Most of us use the MPLAB which is available for free downloading from Microchip.

Depending upon your resouces/time there is also the little Pickit II from Microchip. I'm pretty sure that it's right around $50.00 (US) with a little demo board that has some tutorials that can get you up and programming almost right away. Some of the larger pics can also be used to do debugging if you are willing to spare out some of the pins for it. Usually they are the programming pins anyway.

Heading to the internet, one can join the MIT pic group which is quite active (although not restricted to information about pics).

Other sites:

http://www.ottawarobotics.org

http://www.hbrobotics.org/

Hummmm, the last one is the "local club" of folks. I know a couple of members. They are into pics. They are located in San Jose, Ca (where I live). You might have a local club near you for a chance to grin and hoist a few beers. Interesting, that this site/group states:
"The HomeBrew Robotics Club was resurrected from the ashes of the original HomeBrew Computer Club". That brings me back to 30 years ago when we met up at Stanford Linear Accel.

Anyway, I digress. This should give you a good start at doing some of the work to get started without breaking the bank.

Hope this helps.

Cheers,

Rich S.

 

[dseaver]

I understand the whole "not for students" part, as I am a member of tek-tips, and contribute to and receive help from the C# forum for work. It creates a better resource for professionals

 

[richs]

Hiya-

The other things you might consider:

1. High level programming language. The PicKit (PicStart 2) mentioned earlier comes with a "lite" version of their C complier. I use CC5X for doing applications in C. The first project is free, then for follow on products, one should buy it.

2. Basic STAMP. you program the critter in basic, and you are ready to rock and roll. I am lead to believe they use the PIC processors inside. They usually run about $50.00 each. I have no experience with them.

3. You might want to wander over to:

http://getok.net

and look at the little ladder logic compiler that I whomped up. This is a programmable logic controller. It uses a graphical programming language designed for electricians to program with. They have been around for years. With the application that you mentioned, it is relatively trivial to program with ladder logic. The PLC mentioned can send and receive RS232.

As for an output device, I might suggest an optically connected triac for your application. A good part number escapes me right now. I'm sure one of the others will be able to supply a reference. Sorry, I don't have that notebook with me right now.

Best of luck and keep us posted on your progress.

Cheers,

Rich S.

 

[dseaver]

Thanks for the info, I think i'll end up leaning towards using a c compiler. I am very familiar with C/C++/C#, so its best to focus my efforts there. Again, thanks with the help so far!

 

[BobM3]

Here's one for PICs:

http://www.cnczone.com/forums/forumdisplay.php?f=281

 

[AHay]

Try the arduino:

http://www.arduino.cc/

Not very expensive and very easy to use.

 

[dseaver]

I am trying to assemble a parts list for my setup (I went with Arduino, btw) and I was looking at relays and found this

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=PB874-ND

Now is this overkill for the sprinkler valves (they use 24VAC). I am not sure what I am looking for in a relay and this seems to fit the bill. I want to control the relay with the output of the Arduino using a setup like this:

http://www.arduino.cc/en/Tutorial/ShiftOut

Where I am going to use a shift register to make sure I have enough outputs

 

[SteveMeisel]

I doubt that you will find a better place than:

http://www.nutsvolts.com/

These guys are PIC guru's. I've been getting the magazine for several years now. Still haven't tried a PIC. I like my Freescale products here at work and play with them at home.

 

[MacGyverS2000]

Steve,

I've lightly considered introducing some of the Freescale offerings into my products... how do you like them? What are you using to program them, a simple JTAG unit or a direct chip programmer with a spring-loaded socket?

Dan - Owner

http://www.Hi-TecDesigns.com

 

[geekEE]

Dan,
I don't know which Freescale products you've been thinking about, but I've been using the 68HCS08 parts a lot at work. I've been programming them with a JTAG-like USB programmer. The Codewarrior development environment is pretty nice, but the free version is limited in binary size and in the number of "beans" (automatic C code generators) that it supports. Of course they'll be happy to sell you an upgrade to the full-blown package (

http://www.freescale.com/webapp/sps/site/overview.jsp?nodeId=0127262E703BC5).

I've got the Professional version and it makes code development quick (although not necessarily the tightest code). I'd recommend it if your projects have the quantities to make the higher-end tools worthwhile.

Glenn

 

[SteveMeisel]

Dan,
Sorry for the slow reply.
We use direct chip programming.

Steve

 

[MacGyverS2000]

I'm going to revisit them at some point in the near future... their smaller offerings match up functionality-wise with the PICs I'm using, but the price point is a bit better (10-20%).

Dan - Owner

http://www.Hi-TecDesigns.com