Here goes . . .

[zachtheterrible]

I am going to start using PICs . . . "Yeah, 'bout time" is what all of you are thinking :lol:

Remember that security system that I was working on? Well, I figured that instead of using a load of 555's necessary to make delays and to turn stuff on and off at the right time, I could simplify my design considerably and use a PIC. I would also like the PIC to be able to decode signals from holtek encoders that I am using. I'm sure that it's possible, but just how complicated is that for a beginner like me?

In Jay's sticky he said that the 16F628 is great for the beginner. I think I'll get a couple of those to experiment with and teach myself first. I also am going to need to make or buy a programmer, does it matter that I use linux when making the hardware? Obviously I need software for linux. I tried accessing the one that Jay posted in his sticky but I couldn't connect.

The 16f628 has 18 pins, does this mean 18 output/input pins, or 18 pins all-together, including gnd and vcc etc . . .?

Thanks everyone, I would be hopelessly lost without all of you guys :lol:

 

[ym2k]

The 16f628 has 18 pins, does this mean 18 output/input pins, or 18 pins all-together, including gnd and vcc etc .

I will recommend you to get 16f628a since is cheaper. It had a total of 18 pins. Taking away vcc and gnd, it leave you with 16 I/O pins. Since MCRL can only take input, you are left with 15 I/O pins. If you need an external oscillator for higher frequency operation, this will take away another 2 pins which left with 13 I/O pins. Lol, which is exactly what you have with 16f84a. But since 84a is way too expensive and with less features, 16f628a is still the more popular choice.

For more understand about 16f628a, is better you read thru the whole pdf document in microchip sites. Good luck with your encounter!

 

[zachtheterrible]

If you need an external oscillator for higher frequency operation, this will take away another 2 pins which left with 13 I/O pins

13 pins is more than enough. How high can the lower frequency operation go? I'll have to check what the holtek decoder oscillates at.

Thanks ym2k :lol:

 

[ym2k]

If you need an external oscillator for higher frequency operation, this will take away another 2 pins which left with 13 I/O pins

13 pins is more than enough. How high can the lower frequency operation go? I'll have to check what the holtek decoder oscillates at.

Thanks ym2k :lol:

628a had an internal precision oscillation of 4mhz, with frequency crystal, it can goes as high as 20mhz. If you use the internal oscillation, you save 2 more I/O!

 

[Nigel Goodwin]

The 16f628 has 18 pins, does this mean 18 output/input pins, or 18 pins all-together, including gnd and vcc etc . . .?

I suggest you try my tutorials, which explain why they are based on the 628!.

 

[Jay.slovak]

Good decision to start with PICs and 16F628A. Yes it has 18pins, two are power one reset and two oscilator. I strongly recomend to use internal 4Mhz oscilator (it's way faster than what you really need), so you can use 14~15 I/Os. This is a good chip for beginners (Later you should switch to 16F88 that has ADC and more peripherals). Nigel's tutorials should have enaugh info to start with PICs from scratch.

 

[zachtheterrible]

Alrighty than, ill use the 16F628A.

Now, about programming it, can I use linux instead of windows? If not its no sweat, I have windows on a seperate partition on my system.

Also, what's my best bet for a programmer? kit? make myself? buy it pre-made?
Whichever is cheaper :lol:

 

[Joel Rainville]

Alrighty than, ill use the 16F628A.

Now, about programming it, can I use linux instead of windows? If not its no sweat, I have windows on a seperate partition on my system.

Also, what's my best bet for a programmer? kit? make myself? buy it pre-made?
Whichever is cheaper :lol:

For software on Linux, have a look here :

http://www.sxlist.com/techref/microchip/16F877/taitlinux.htm

For the programmer, build yourself one of David Tait's original programmer variants, like a nice P16PRO or P16PRO40 with or without a cool ZIF socket. Or do it the cheapy way like me and have one sitting on the corner of a breadboard, until you decide what you really want. :lol: The original David Tait design works very well and is very easy to build. A 7407 buffer, 2 transistors, a few passives and a DB25 connector. Everything mentioned here is one Google search away. Nigel's sites has a link to a P16PRO40 schematic if I recall correctly..

 

[Nigel Goodwin]

Now, about programming it, can I use linux instead of windows? If not its no sweat, I have windows on a seperate partition on my system.

Linux support is pretty poor, but you can get a basic minimum of what's required, if you check on http://www.piclist.com there's a section about Linux.

If you've got a Windows partition you may as well use MPLAB and normal Windows programmers?.

 

[zachtheterrible]

Yeah, I'll just use windows.

When looking at the PICs that the P16PRO can program I only saw PIC16C... Just to make sure, it can definetaly program PIC16F628A right?

 

[Joel Rainville]

Absolutely. In fact, I suspect the P16PRO can program most PICs that support serial programming methods, although you'd have to have a flexible socket solution to accomodate different pinouts, and a programming software that supports the device.

Most programming software support both the 16F628A and the P16PRO, like WinPicProg and IC-Prog, among others.

 

[bryan1]

Hiya Zach,
Eh mate on Nigel's site is a link to the Ozipic's programmer schematics, below is a pic of it. It's the first time I've ever made my own circuit board and it's so hot of the press I haven't put in the 74HC14 chip or the power supply yet. I've just got to check there is no shorts on the solder side then tonite I'll try it out. Rather than go straight ahead and make the ICD clone I made this programmer as it's got ICSP on board and also I had all the bits. What do you guy's think of my first foray into makin me own circuit boards.

Cheers Bryan

Edit:- Well after spending all day trying to get it to work after continually getting the dreaded error at 0x00000. I ended up replacing half the transistors and played with the lm317 only to finally conceed defeat and go ahead with my original plan, which is build an ICD clone on veroboard. Well I did learn a good lesson don't bother making me own pcb's when veroboard is just as good for most projects. My attempt at using press'n'peel worked after the 4th attempt and sore fingers from scrubbing the board clean. Well after 3 days of work I put it down to a good lesson don't change tack just cause something looks good.

 

[zachtheterrible]

bryan, don't give up!! PCBs are the way to go!! Just beause this one didn't work doesn't mean the next one won't. PM evandude about his PnP blue sheets, he is always bragging about how well they work, probably a lot better than the ones that you have. I have converted to the phototransfer method and have been getting superb results.

One last question before I buy all the components, what is the difference between P16PRO and P16PRO40? And what are ZIF sockets?

Nigel, I will definately be using your tutorials.

 

[Joel Rainville]

bryan, don't give up!!

Yes Bryan, don't give up! I might not have the wisdom of Nigel and audioguru (think about it, their combined age is more than 110 years, and I think they might be telling us their age in hexadecimal... :lol, but one thing that I've learned early is that perseverance always wins, no matter what you're trying to do.

What you have in your hands is not a faulty PCB but an invaluable learning experience. Chances are you will learn a lot by fixing it. Stick to it! Then, when it finally works, build an ICD2 on Veroboard. And finish that too

 

[Nigel Goodwin]

One last question before I buy all the components, what is the difference between P16PRO and P16PRO40?

40 :lol:

But more seriously, the P16PRO40 accepts all PIC's from 8 to 40 pin, the P16PRO only accepts 18 pin ones. The 40 has an extra Vpp line (Vpp40) which is used to select 28 and 40 pin PIC's in a single 40 pin Aires ZIF socket.

And what are ZIF sockets?

Zero Insertion Force - you open a little lever, drop the chip in, and close the lever again to make contact to it - VERY ,VERY easy, and useful.

 

[zachtheterrible]

40 Laughing

Oh :lol: . Guess I'll go with the P16PRO40 then, since it will more than likely be useful later. as well as them nifty ZIF sockets :lol:

 

[eblc1388]

Why are so many people having troubles building the P16PRO40? I would guess they have no idea where to look/check to resolve the mistakes, which are easy to rectify if they know where to look. There are lots of advice on the NET but none provides a step by step method to reach the ultimate goal.

 

[zachtheterrible]

What voltage input do i err... input? :lol:

Is it AC or DC?

 

[bryan1]

yea my major problem I think is the mlcr isn't rising fast enough to put the pic into programming mode. I placed the probes off my fluke 865 on the mlcr pin and found as soon as I hit program on the laptop it takes up to 2 seconds for the pin to rise to 13 volts. Also I'm using a 74hc14 chip as recommended on the schematic so that could be a concern too. The ozipic circuit uses a LM317 for the Vpp and I reckon this is where my problem is with varing voltages. Unfortunatley I'm about 60 k's from the nearest electronic store so I can't just zip down the road to get more bits . O'well I'm off to try again as I'm without a programmer now I've shipped mine of to the US.

Cheers Bryan

 

[Joel Rainville]

it takes up to 2 seconds for the pin to rise to 13 volts

It's very unlikely that it's taking 2 seconds. I'd say your meter is taking 2 seconds to read the 13V... What software are you using? Did you try to adjust the programming delays?