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JDM pic programmer help required

kh_hamzas

Sep 10, 2012
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For the following circuit of the JDM pic microcontroller programmer I need information about the PIC microcontroller pins which receive the RS232 signals and the timing diagram of the PIC processor when information is being downloaded into it through the RS232 link. I am really really desperate and I absoltely could not find anymore help on the internet for this:
 

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CocaCola

Apr 7, 2012
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I need information about the PIC microcontroller pins which receive the RS232 signals and the timing diagram of the PIC processor when information is being downloaded into it through the RS232 link. I am really really desperate and I absoltely could not find anymore help on the internet for this:

Go to microchip's site and download/read the programming specifications of whatever chip, the algorithms vary so that information will vary with each particular chip...

If you want more details of the JDM programmer you can visit his websites that has some source code and lots of info...

http://www.jdm.homepage.dk/newpic.htm

BTW the JDM although popular due to it's simplicity, is not a reliable programmer...
 

kh_hamzas

Sep 10, 2012
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i tried looking for various data sheets. didnt help much. i am basically looking for timing diagrams. any microcontroller such as p16f87x and an eprom of the 24c series will help. any help will be very very grateful. i am an uber noob at this and need this info desperately.
 

CocaCola

Apr 7, 2012
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i tried looking for various data sheets didnt help much.

Did you look on microchips site under programming specifications?

http://www.microchip.com/TechDoc.aspx?type=Programming

i am basically looking for timing diagrams. any microcontroller such as p16f87x

http://ww1.microchip.com/downloads/en/DeviceDoc/39607c.pdf

That should be everything you need to know about programming that chip...

and an eprom of the 24c series

Again go pick up a datasheet (for whatever specific chip) and read away, note that a 'generic' programming algorithm for 24c series EEPROMs is not going to work with all of them, you may need to tweak the algorithm to each of the different manufactures specifications... The EEPROM datasheet will have the timing and specifics of how to program that chip...

i am an uber noob at this and need this info desperately.

Good luck, it's A LOT to wrap you head around and I can't even phantom a newbie tackling this...
 

kh_hamzas

Sep 10, 2012
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thanks for your help and the links. but as i mentioned before, i have gone through them. but nothing really helps me out with the RS232 connection. i am totally unable to translate what the data sheets inputs and outputs are being referred into the jdm circuit with the rs232 connection. :(:(:(
 

CocaCola

Apr 7, 2012
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but nothing really helps me out with the RS232 connection.

You didn't asked about the connection you asked...

I need information about the PIC microcontroller pins which receive the RS232 signals and the timing diagram of the PIC processor when information is being downloaded into it through the RS232 link.

That is clearly answered in the datasheets I linked, with pretty pictorial representations of the data stream...

i am totally unable to translate what the data sheets inputs and outputs are being referred into the jdm circuit with the rs232 connection. :(:(:(

Match the pins up, between the schematic and the datasheets...

It's NOT easy stuff, if you are a total newbie you will need to build a very solid foundation of serial communication before you will be able to understand what you want to understand... This isn't going to happen overnight, its going to take many hours of study...
 

BobK

Jan 5, 2010
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How much is your time worth? A PICKit 2 programmer from Microchip costs all of $35 and you will save many hours by buying one.

Bob
 

velocina

Oct 22, 2012
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For the following circuit of the JDM pic microcontroller programmer I need information about the PIC microcontroller pins which receive the RS232 signals and the timing diagram of the PIC processor when information is being downloaded into it through the RS232 link. I am really really desperate and I absoltely could not find anymore help on the internet for this:

Which software do you use to transfer the .HEX file from the MPASM assembler to the PIC through the RS-232 interface ?
If it is ICprog (in JDM mode) no problem could be encountered.... I've started with a JDM programmer too, but now I have a PICKIT2 and use it.

Please note that the MCLR pin must be powered by +13.5 V during programming (I refer to PIC16F84A), while the PIC is powered by +5 V.
I've found that using RS-232 port signals to obtain programmer power supply is not so reliable, due to the fact that not all PC's RS-232 ports deliver a sufficient positive voltage for programming ( most of USB to RS232 converters use 9 V RS-232 signals ...).
Furthermore we are talking of signals, not power supply....

I suggest you to measure voltage on your RS-232 port and try to use an old PC that probabilly meets your requests in terms of voltage and current better than a portable one.

Also founding a bit more complex programmer ( e.g.: JDM with serial interface using a MAX232 Ic and a separate power supply ) may be a good idea.

Bye.

Luca
 

wingnut

Aug 9, 2012
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I just bought a Pickit 3. It took much prayer, fasting and techical support (my son) to get an LED blinking on a PIC12F510. Mikrobasic does not support this chip, so had to use Jal.

My heart goes out to you guys trying to get a programmer to work without a boffin physically present to help :)
 

CocaCola

Apr 7, 2012
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My heart goes out to you guys trying to get a programmer to work without a boffin physically present to help :)

The JDM programmer was a nice proof of concept when it came out... But, IMO no one should consider it as a legit alternative programer today, fun to play with but not ready for prime time any longer...

As has been said you can get a pickit 2 clone for dirt cheap, $20 delivered even... A programmer the will actually work for the task and has official support...
 
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