kronos web site sucks!!!!

[goner19]

ok kevin,

this might be the dumbest question of all time

but do i need to be transfering or atempting to transfer data to check pins 2 and 3?
what i am asking does it have to happen in the split second between hitting the program button and the writing to chip error?

[goner19]

i checked all the caps around the rs232 : 2 are giving me a postive voltage , 2 give me some kind of double voltage and one is a negative voltage. i am assuming that all are doing what they are intened to do....

[psycho]

this might be the dumbest question of all time

but do i need to be transfering or atempting to transfer data to check pins 2 and 3?
what i am asking does it have to happen in the split second between hitting the program button and the writing to chip error?

PULL THE PIC OUT FOR THESE TESTS...
You won't damage it if you don't but you will know that the PIC is not goofing up your results.

In the MAX 232 datasheet:

The MAX220–MAX249 have two internal charge-pumps
that convert +5V to ±10V (unloaded) for RS-232 driver
operation. The first converter uses capacitor C1 to double
the +5V input to +10V on C3 at the V+ output. The
second converter uses capacitor C2 to invert +10V to
-10V on C4 at the V- output.

Therefore, you should see +10v on pin 2 and -10v on pin 6. Note that on my setup, I showed closer to 9v and -9v.

If you have these voltages :

You are going to need data going to/from the chip to check for signals. The first thing I would do is fire up your SCOPE (NOT your DMM... Too slow). Connect the board to the serial cable and either use the programming software or better yet, a terminal program if you have one and know how to use it.

Pins 8 & 13 are the inputs to the rcvrs in the MAX232. If you use a terminal program, send a long file (or keep pressing chars on the kbd) to the device. You should see activity on one of those receiver lines (on the MAX232). If you do see activity (voltage swings), you know that the computer is sending info... If not, check your setup because there is nothing coming from your computer.

Pins 9 & 12 (on the MAX232) are the outputs for each of the 2 rcvrs. Chances are that it goes to the USART (serial port) in the PIC so, you can trace those lines into the socket (I would think that only one line is active). I think the PIC was an 18F4620 which means that the rcvr for the USART is on pin 26. I would also guess that they used the built in hardware port instead of doing it all through software. If you get activity on pin 9 or 12 of the MAX232 then the MAX232 should be good to go. Check the signal also at the PIC socket pin 26.

If you made it this far you know the receiver in the max232 is working. Now, remove the PIC if haven't already and place a jumper (wire) between pin 26 (the rcvr) and pin 25 (the xmtr) of the PIC. If the transmitter works, everything you type should be echoed back to your computer. If that happens, then you know that the serial port part of the circuit (the MAX232) works correctly.

Let me know what you find out.

Hope it helps,
Kevin

[psycho]

BTW, if you don't know how to use your scope yet or you don't have one (but if I remember right, you do), you might be able to get away with using a DMM... Not recommended, though.

Also, if you don't see the data coming from the computer, look for it on pins 7 & 14 of the MAX232. If you see the data there, you, my friend, have what is known as a null modem cable instead of a strait-through cable. Get a straight though cable

Kevin

[psycho]

fwiw, I was looking through the manual for the budget board and found something very interesting... If you look at the very bottom of page two - Just above where is says page 2, you will notice a 7 spot for a 7 pin header. All of the signals that you need to use a PICKIT2 are right there. You need PGD (marked as RB7), PGC (RB6), Vdd, Vss & Vpp/MCLR . If you are interested, use a continuity tester and see if those signals go to:

Vpp = Pin 1 of PIC
Vdd = Pin 11 & 32
Vss = Pin 12 & 31
RB6 = Pin 39
RB7 = Pin 40

Those are the only 5 signals you need to program a PIC that has ICSP capabilities and all 18 series PICs do. The layout is different than the PICKIT2's connector but you could easily make a jumper harness for it. Also, if I remember right, all 40 pin PIC18's have the same pinout as far as ICSP is concerned so you could plop other chips in there, too.

Just tryin to help....

Kevin

[goner19]

kevin you are a god!!!!


thanks for the info
i do have a scope ....im gona run your tests in the a.m.

[goner19]

so what you are saying is that if i got the pickit2 i could bypass the max232 all together?

interesting...

[psycho]

Not a god... I am barely human

After re-reading my responses, you could cut some red tape and go straight to removing the PIC and placing the jumper in the empty socket between pins 25 & 26 and if that works right off, you know the RS232 part of it all works. If the chars don't get looped back to your computer, run the tests I outlined to see where things go awry.

Let me know what you find.

Kevin

[psycho]

You posted while I was typing the above message... If those ICSP signals (Vpp, RB6, etc in the corner of the board) go to where they should go (by what is silk screened on the board), then no.

If you had a PICKIT2 and you made a harness that would allow you to use the goofy pinout that his board has, you would not need the RS232 port to program a PIC. Note that if you program the DIOS PIC in this fashion, it will no longer be a DIOS PIC, it will just be a PIC because what makes it a DIOS is the firmware on it. If you write over that firmware then it will be gone forever as I am quite sure the code is protected so that you can't read it out of the PIC.

All that being said, if you do choose this route, you can use just about any PIC18F 40 pin chip in there and they WILL NOT cost you $40/pc.

The board works like this:
On it, it has a PIC with DIOS firmware on it. The firmware most likely has bootloader capabilities in that when it gets a command to program (through the serial port), it will overwrite the USER portion of the flash memory (as specified by whoever makes the DIOS).

So, no, the RS232 is NOT required to run a PIC. It IS required to program a DIOS because it uses a combination of the firmware in the chip that makes it a DIOS and the software on your PC through the serial port.

The ports (in the DIOS, they call them 0,1,2,...) are actually called something else inside the PIC but as long as you know where all 32 (???) of those port pins connect on the PIC's socket, you can map them to the "real" names inside the chip (i.e. PORTA, PORTB, PORTC, PORTD, PORTE) and then use ANY PIC compiler and a PICKIT2 and just use it as a regular PIC. As I said before, if you program something else over the DIOS firmware with a PICKIT (or any other "real" programmer), it will no longer be a DIOS.

If you choose to do that, get the PICKIT2 and just use the board as any other dev board with a PIC on it. But you WONT be able to use the chip as a DIOS anymore.

I hope I got the point across about the non-reversible implications of programming a DIOS via a "real" programmer.

Kevin

[goner19]

ok now you are a god of gods!!!

that is the simple question i was looking to answer when i first bought into PIC's
what is the diffrance between all the chips and companies that offer them. when i found out that they were all basicly made by microchip and saw the price differance i was really confused.

so Kronos (the dios "manufactor") just put some stupid propritiroary (sp?) software on the chip so that you are stuck using their dumb products.

i could careless about being brand loyal. in fact i prefer the straight dope rather than getting it cut for some substandard source.

i now have 2 pic18f4620. one is a "dios" (38$) the other straight from microchip (6$). so im not afraid on "losing" what ever advantage of using their frimware would be

so do i need a differant complier besides the dios software? since i am going to use the pickit2?

[goner19]

duh you answered that question i just saw it i can use any complier

[goner19]

the pickit2 looks like it only works with 20pin chips
and the 40pin unit looks like a smt.

am i over looking something?

[psycho]

If you are going to use C, look here (made by Microchip for PIC18 series chips):
http://www.microchip.com/stellent/idcpl ... e=en010014
There is a very capable free version (free is always good!)

You will also want to check out MPLAB which a lot of people use as their IDE and it also allows source(C and ASM) level debugging via a PICKIT2. Also an assembler and linker. I believe you can go to http://www.microchip.com/mplab and get it (free)

This is the PICKIT2 package I have($49):
http://www.microchipdirect.com/products ... s=DV164121
Note that the uC is a PIC16F series chip which means that the above C compiler won't work for it. But, look on the Microchip website for the HiTech PICC compiler and you will have another little demo board. Not too shabby for half a C note.

I noticed they also have this one now ($99):
http://www.microchip.com/stellent/idcpl ... e=en535806

Also, when I said "any compiler" I mis-spoke... Any non-proprietary compiler. i.e. you don't have to buy the chips from the maker of the compiler.

If you like Basic, I can recommend PicBasic - been around for a long time therefore there is a big userbase and alot of example code on the net (based solely on remarks/comments from other people). It looks like you will have to get PicBasic Pro for the PIC18F series. Like I said, never used it but it is extremely popular!
----------------
You already posted.... The board that comes with it, like I said above is sorta a gimme... Just thrown in with the PICKIT2. But, like I said, you will need another compiler besides the C18 compiler. Don't fret, though... MPLAB can handle multiple compilers and you can choose which compiler to use with your project properties. Don't let the size of the "gimme" boards fool you. They are laid out very well and you'll be surprised how usefull they are. The SMT one has a PIC on it and I believe the 28 pin board comes with a PIC (maybe two, didn't read the details). Essentially, when you get the PICKIT2, you will have two boards to play with - the one you already have and the one that comes with it.
---------------
Kevin

[psycho]

Nuts! I forgot to mention that MPLAB has a simulator, too.

Kevin

[kheston]

goner19,

The Arduino compiler is free and open-source, just in case you go down that path and some point.

I got my PicKit2 in the mail on Friday and was able to put together a simple circuit to blink a couple of LEDs over the weekend. I'm using the 12F683, an 8-pin µC that the PICAXE 08M is based upon:


(clicking makes them bigger)

I went with the Lite (free) version of Hi-Tech's C compiler. Here's the code:

Code: Select all

#include <htc.h>

__CONFIG(INTIO & MCLRDIS);

#ifndef _XTAL_FREQ
	#define _XTAL_FREQ 4000000
#endif

void init(void)
 {
  OSCCON = 0b01100000;  // internal 4MHz osc
  ANSEL = 0;            // A/D disabled
  CMCON0 = 7;           // comparators disabled
  GPIO = 0b000000;      // all GPIO low on power up
  TRISIO = 0b000000;    // all set to output mode
 }

void main(void)
{
   init();

   while(1)
   {  
     GPIO4 = 0;
     GPIO5 = 1;
     __delay_ms(100);
     GPIO4 = 1;
     GPIO5 = 0;
     __delay_ms(100);
   }  
}