Where can I find the complete circuit diagram for PIC pgrogrammer?

[thecritic]

The three main reasons for this are.

• Microchip keeps the software up to date on these programmers regarding devices.
• The Pickit2 and 3 are also ICDs, In Circuit Debuggers.
• The Pickit2 is only $35 (plus shipping).

Not everyone likes debuggers but they are very powerful tools.

The shipping can be expensive. But if you buy a few PICs at the same time it is less painful.

In the past I have suggest to cobble a simple programmer together and then use it to build a pickit2 clone.

I appreciate the concerns regarding my future. Thanks for that.
But the situation with me is different. I currently only need a cheap programmer to program 16f877a. No need for ICD, no need for future support, no need for other things. Thats my need. I hope you will understand.

 

[Jon Chandler]

And I am amazed at how many people continue to build JDM-style programmers and spend money on USB adapters, external power supplies and band-aid fixes to try to get the stupids things to work...no matter how much it actually costs or how long it actually takes.

Maybe, just maybe, the people recommending the PICkits have learned from their mistakes along the way.

 

[thecritic]

And I am amazed at how many people continue to build JDM-style programmers and spend money on USB adapters, external power supplies and band-aid fixes to try to get the stupids things to work...no matter how much it actually costs or how long it actually takes.
Maybe, just maybe, the people recommending the PICkits have learned from their mistakes along the way.

I am amazed at your amazement. Didn't you make effort to know why people continue to do that? Do you think they are stupid? There may be several reasons why people would chose to do it that way, 'the hard way'. But I don't think you are interested in knowing them.

 

[Wp100]

Hi,

Well all we are trying to do is give you the benefit of our experiences with Pic programming.

Many of us have started the way you are doing and when we got the Pickit2 we all wondered why we had spent so much time, effort and money messing around with problematical serial and parallel programmmers.

As I said eariler I'm sure any ET member in your country would be more that happy to give the Pk2Lites chip is initial programming.

If you want to continue on the parallel route the attached file is a decent parallel port programmer project I did to complement a larger pic project.
It just uses very common and low cost parts and needs a 15v to 20v ac or dc adaptor / power pack.

 

[thecritic]

If you want to continue on the parallel route the attached file is a decent parallel port programmer project I did to complement a larger pic project.
It just uses very common and low cost parts and needs a 15v to 20v ac or dc adaptor / power pack.

Thanks for that.
But isn't your design basically the same as this https://www.oshonsoft.com/picproghard.png
Or is your design any better?
I am asking this because, I have already bought parts (about 5 hours ago) for the designed I linked.

 

[3v0]

I am amazed at your amazement. Didn't you make effort to know why people continue to do that? Do you think they are stupid? There may be several reasons why people would chose to do it that way, 'the hard way'. But I don't think you are interested in knowing them.

In general I would say the are uniformed rather then stupid.

The simple programmers are often penny wise pound foolish endeavors. By the time you get them working you could have built or purchased a pickit2. On the other had some people have built and love their simple programmers. But it is a path that often leads to appointment, esp the JDMs.

 

[Wp100]

Hi,

Yes it seems very similar - just that I know mine works and it has a simple pcb design and some practical notes - sure you will be happy this the oshonsoft one as well.

 

[thecritic]

Regarding this desing https://www.oshonsoft.com/picproghard.png, I came to this confusion
What is the pin no. for following pins 16f877A?
1. Data
2. Lvp
3. Clock

(I thought Clock pin is 27(the serial programming clock PGC, pin); Lvp is pin 24 (the PGM pin); Data is pin 28(the PGD pin))

 

[Wp100]

Hi,

If you follow that diagram you will see that LVP - Low Voltage Programing is taken to 0v via a 10k resistor.

LVP is not normally used and during programing it is tied Down to 0v to avoid accidentally involking that mode.

Look at the 16F877A datasheet for the ProGraming Data and Clock pins - similarly with VPP which controls Programming Mode.
The programming pins vary depending on the chip so you must check each type - many are the same but many are not.

 

[thecritic]

Hi,
Look at the 16F877A datasheet for the ProGraming Data and Clock pins - similarly with VPP which controls Programming Mode.
The programming pins vary depending on the chip so you must check each type - many are the same but many are not.

The datasheet says that pin 40 is Rb7, In-circuit debugging and Serial Programming Data pin. Is this the pin You are referring to Programming Data pin? (I need to confirm this because, there are several data pins.)

The Datasheet says that pin 39 is "Interrupt on change pin or In-Circuit Debugger pin. Serial
programming clock" . Is this the Clock pin? (There are several other clock pins)

(Sorry for repeatedly asking for the same thing, but I can't risk damaging my brand new PIC. )

 

[3v0]

You are correct. Use RB6 and RB7. The should also be marked PGD and PGC.

 

[Pommie]

Hi,

If you follow that diagram you will see that LVP - Low Voltage Programing is taken to 0v via a 10k resistor.

LVP is not normally used and during programing it is tied Down to 0v to avoid accidentally involking that mode.

There is no need to tie LVP low. When Vpp appears on MCLR the LVP pin is ignored. If it didn't then ICSP wouldn't work.

Mike.

 

[thecritic]

One final question and I am off:
In the design, The Data Pin of the PIC and the output of IC1(2) seems to shorted. This is required during writing Data.
But during Read, won't it pose problems, because the Data Pin of the PIC would be output then and we have two Outputs shorted-together!
**broken link removed**

 

[ericgibbs]

One final question and I am off:
In the design, The Data Pin of the PIC and the output of IC1(2) seems to shorted. This is required during writing Data.
But during Read, won't it pose problems, because the Data Pin of the PIC would be output then and we have two Outputs shorted-together!

hi,
You only have two outputs shorted together IF, IC1/2 output has been set LOW by its own input.
The two outputs are OR'd together when the program is controlling the pins...

NOTE: the IC's are open collector types.

 

[thecritic]

hi,
You only have two outputs shorted together IF, IC1/2 output has been set LOW by its own input.
The two outputs are OR'd together when the program is controlling the pins...

NOTE: the IC's are open collector types.

Thanks. As I expected, I needn't worry!

 

[thecritic]

I got stuck. The parallel port Pic programmer didn't work.
I just wired a Led between pin 25 and pin 2, to see if it glows when I try to program, but, hell no.
I even used the programs 'check hardware' features, but, hell, no Led glows.
Anybody, can you please, help me in this!

 

[Pommie]

I got stuck. The parallel port Pic programmer didn't work.
I just wired a Led between pin 25 and pin 2, to see if it glows when I try to program, but, hell no.
I even used the programs 'check hardware' features, but, hell, no Led glows.
Anybody, can you please, help me in this!

You've done something wrong. Double check all the connections.
Check that you have 13.2V and 5V.

Mike.

 

[thecritic]

You've done something wrong. Double check all the connections.
Check that you have 13.2V and 5V.
Mike.

I have done so little to have done something wrong. I finished making the programmer but before I hooked up the programmer to the parallel port I decided to check the working of the parallel port by just connecting an led (in series with 560R) between pin 2 and pin 25 of the port. But I am having hard-time even to glow this single LED.

 

[Pommie]

You may have damaged your parallel port. They are not designed to light an LED.

Mike.

 

[thecritic]

The problem was with the PC. I switched to another old PC, it worked there (the led glowed). But I don't know, if its the issue with the OS (both Xp), or the parallel port itself.