[Poland] PIC reflash

[salab]

Hello all

I am new user here (altought I read this forum for some time back), so first of all I would like to say - hello everybody

Recently I bought a second hand MiniMig and as I noticed  it has some problems with PIC. I tried to reflash it via RS232 (doublechecked cable, tiny bootloader, COM settings, etc.) but still gotsuch errors:

Connected to \\.\COM1 at 115200
  Searching for PIC ...
  pic sending unknown data:  "K" <>  0h=
Check baudrate & Start Write while PIC is not sending serial data (e.g. in reset)
  ERROR!

As I read in few other threads (eg. http://www.amiga.org/forums/showthread.php?t=38670) my PIC should be reflashed by PIC programmer.

That is why I am looking for somebody to reflash (I cover all postage cost + payment for reflash service) my PIC microchip with PIC programmer. It would be great if this "somebody" lives in Poland

[guest7146]

Hi salab,

I could potentially help you with reprogramming a PIC device because I have programmers for that here at home, but I've just read the thread you linked to and from what I can tell it was determined that the problem did not exist with the PIC device at all.  In fact, there seemed to be a problem somewhere between the RS232 port and the PIC device.  Nobody ever posted a conclusion stating exactly what that problem was, though.

I presume that there will be some level shifter device between the RS232 port on the motherboard and the PIC.  This is to convert the +12V/-12V signals from the PC to +5V/0V for the PIC.  Perhaps there is a problem there?

Someone else in that other thread suggested removing the PIC (easy if it's socketed, not so easy if it's not) and then shorting out the TX/RX pins on the motherboard.  Then the RS232 connectivity can be easily checked by using Hyperterminal or another suitable terminal program to see if characters are successfully looped back and displayed on the terminal screen when you type away on the keyboard.  Is this something you would feel confident in trying yourself?

AH.

[guest7146]

Oh, and welcome to the forum by the way.  How rude of me!

[guest7146]

I just checked (I know nothing about Minimig) and it looks like the PIC is socketed? So that means the suggested COMs test can be easily done.  If you feel confident enough, do the following:

1. Remove the PIC from the motherboard
2. Apply a short between pins 17 and 18 as shown on the schematic attached below.
3. Connect your RS232 cable to the motherboard.  Start Hyperterminal on your PC.  Start a COM connection in Hyperterminal.
4. Power up the Minimig Motherboard.
5. Start typing characters on your PC keyboard.  If your PC COM port is activated and working, and your RS232 cable is wired correctly, and the level shifter on the Minimig motherboard is working properly, then the characters you type shouled be looped back and displayed in your terminal window.
6. If no characters are looped back then the PIC is not likely to be the problem.  If you are confident that your PC COM port is working and that your RS232 cable is wired properly, then suspect a problem with or surrounding IC2 (SP3232) on the Minimig motherboard.

Hope this helps.

AH.

[salab]

Hello AppleHammer

Yes, before I posted here I tried all the methods and tricks posted at amiga.org and other places including the trick with pins 17 and 18 - I get echo (echo letters  were different than the one I input on PC keybord). Thank you for your help, but this one just not work. It looks like the PIC is old version without bootloader and needs to be reprogramed with hardware programmer.


PS: I contacted yaqube via PM and he is going to help me solve this problem

[guest7146]

Hello AppleHammer

including the trick with pins 17 and 18 - I get echo (echo letters  were different than the one I input on PC keybord).

This is not correct behaviour.  The echoed characters should be the same as those typed on the keyboard, and if they are not then there is something wrong with the RS232 line somewhere.  I would not suspect the PIC at this point.

PS: I contacted yaqube via PM and he is going to help me solve this problem

Ah, good.  I hope you get it sorted.  If you do, please post back the solution here!

AH.

[salab]

As soon as my MiniMig will be working, I will, for sure

[salab]

I got PIC reprogrammed by yaqube today and I have just finished some intensive tests.

I use FPGA FYQ091224 and so far everything works nice and smooth.  Reprogramming PIC solved all my problems. I did not try to reflash PIC  myself, but as I was told by yaqube - I can do it easily now as PIC has  bootloader now.:banana:


THANK YOU YAQUBE

[guest7146]

Fantastic! Glad you got your machine working and thanks very much for posting the info!

...I need to get me one of those Minimigs.

[salab]

You cant even imagine how happy was I when I successfully launched some old classic games on working MiniMig

[loedown]

That still leaves the question as to why the Minimig wasn't TX / RX correctly.

[salab]

The problem was old PIC without bootloader.