ICSP (2) questions

[Ramonetnet]

I am trying (without success, of course) to use ICSP, using Low Voltage.

To help to make it work, would some sweet soul answer some of my questions ?

a) can I use RS-232 to program a 18F452 ? What voltage is required ?

I guess I can, as here there is a LVP

>>> http://home.vrweb.de/~lotharstolz/st...vpc/index.html

But I'd like to know the voltage required to make it work, as I have no success,
and my WorkStation only provides 10 volts on the RS-232 interface ...

b) can I program the 18f452 with the crystal installed ?

I guess I can, as the final circuit has to have a crystal and I must be able to re-program it on the board, but I have read it is better not to have the crystal when programming.

I am using MPASM and IC-PROG under XP. Thanks. Ramon.

[Raflex]

I am trying (without success, of course) to use ICSP, using Low Voltage.

To help to make it work, would some sweet soul answer some of my questions ?

a) can I use RS-232 to program a 18F452 ? What voltage is required ?

I guess I can, as here there is a LVP

>>> http://home.vrweb.de/~lotharstolz/st...vpc/index.html

But I'd like to know the voltage required to make it work, as I have no success,
and my WorkStation only provides 10 volts on the RS-232 interface ...

b) can I program the 18f452 with the crystal installed ?

I guess I can, as the final circuit has to have a crystal and I must be able to re-program it on the board, but I have read it is better not to have the crystal when programming.

I am using MPASM and IC-PROG under XP. Thanks. Ramon.

a) Hi, i think that you cant use ic-prog with Win XP, however, you can program the 18f452 with ic-prog and your programmer (maybe jdm) on window 98.

b) yes, you can program it with the crystal installed

[mister_e]

You also need to enable the LVP mode in your config fuses... and forget the specific PGM I/O for future use as it will be dedicated for LVP mode only.

Not a fan of those few components JDM based one...

[Ramonetnet]

mister-e : what one do you recomend then ?
I can spend 30 - 50 euros, but dont want to buy

>>> http://www.microchipdirect.com/produ...rds=DV003001++

Part Number: DV003001 - PICSTART PLUS DEVELOPMENT SYSTEM

It is 136 euros (plus tax, I guess)

I did write to microchip, asked to program a 18F452 and a 18F4520, and they say "DV003001"

Thanks for sharing your opinions !

[mister_e]

PICKIT 2 is the cheapest solution. Sure it doesn't have any Ziff socket, but you can use it + breadboard or home-made adapter.

Since awhile i no longer use my PicStart ... not sure if he's still working

[mvs_sarma]

I strongly support the recommendation of Mister-e and as on date the best and worthy one is PICKIT2

It won't let you down wasting days to fault trace other programmers.

I have one and is working fine. Perhaps you can get it at your local Microchip dealers.
But, Don't be fooled by imitations.However I feel that JUNEBUG from www.blueroomelectronics.com is also performing well and I use it, too.

[mackrackit]

The PICSTART PLUS is a good programmer, It can even be used for ICSP but is not designed for that. As far as programming the 18Fs... About two years ago I was playing with the 18F4320 for the first time, I did not have a PICKIT 2 yet just the PIC START. Putting the 18F in the zif of the PIC START would some times program and sometimes not . Microchip people said I needed to upgrade the PIC START. I bought the upgrade (new chip for inside the PICSTART) and still had the same problem. MICROCHIP then said I needed to add capacitors across the VDD and VSS pins of the chip while it is in the ziff. YEAH RIGHT AS I ONLY HAVE TWO HANDS! That is when I started using the PICSTART as a ICSP. I had to take time to make a few adapters for different chips.

Then I bought a PICKIT2. Came with the six pin header skimask told you about. Plug the header into the breadboard, ran five wires on the board for VSS, VDD, MCLR, and the two going to the programing pins of the chip. Plug the PICKIT2 into the header and it worked. I did not have to modify it at all.

Now all I have to do is add a cheap 6 pin header to my designs and it it ready to program on the fly. I am paying $0.25 USD for these.

That all is not to mention the price difference. The only reason I have a PICSTART PLUS is because the PICKIT2 was not made when I bought it.

That is why I recommend the PICKIT2.

[mvs_sarma]

I am trying (without success, of course) to use ICSP, using Low Voltage.

To help to make it work, would some sweet soul answer some of my questions ?

a) can I use RS-232 to program a 18F452 ? What voltage is required ?

I guess I can, as here there is a LVP

>>> http://home.vrweb.de/~lotharstolz/st...vpc/index.html

But I'd like to know the voltage required to make it work, as I have no success,
and my WorkStation only provides 10 volts on the RS-232 interface ...

b) can I program the 18f452 with the crystal installed ?

I guess I can, as the final circuit has to have a crystal and I must be able to re-program it on the board, but I have read it is better not to have the crystal when programming.

I am using MPASM and IC-PROG under XP. Thanks. Ramon.

1. LVP is not that important unless the device under concern can't take 13V programming. BTW, LVP eats off one pin of Port B and you can't use it in your program anywhere.
2. ICSP you need to momentarily disable few pins used otherwise for the circuit you design.
regards to oscillator, many times PIC18xxxx uses internal oscillators. perhaps, then you need something called Vpp before Vdd facility. so that the circuit wont start and the device is taken to program mode.

The best appears, PICKIT2. if you have time and patience to make few adopters, you don't need the other two parts you referred in your earlier post. Perhaps from spare components lying at home one can make these adopters. Incidentally, if money is nothing before the time lost, you may of course have them

Please put your schematic here and let us see why you are not able to use ICSP facility, Ramon.

[Ramonetnet]

mr Sarma : (I think) I did not say I can not use it (because of my design).
I was trying to say I can not use it because I don't know the electric diagram for it !
(All that stuff about oscillator and Vpp versus Vss...)
Sorry for the misunderstanding !

[mister_e]

See page 31 of the PICkit2 user guide
http://ww1.microchip.com/downloads/e...Doc/51553E.pdf

This should be enough.

[mvs_sarma]

See page 31 of the PICkit2 user guide
http://ww1.microchip.com/downloads/e...Doc/51553E.pdf

This should be enough.

Many a time I have tried but always the download stops before reaching 1,7MB out of 2.08MB or so. Perhaps Microchip may have to replace it.

[mister_e]

Weird... never had any download problem myself

Anyways, when you buy a PICKIT 2, it's on the CD.

I'd post the following suggestion really often here.

http://www.melabs.com/support/icsp.htm

Ok it's for MElabs programmer, but the idea is the same.

Microchip solution... the one in the PDF
<img SRC="http://www.picbasic.co.uk/forum/attachment.php?attachmentid=2542&stc=1&d=120915241 1">

Almost the same... but the last one don't talk about the load on PGM pin, and don't show the cap on Vdd.. which is not important... but mandatory!