View Full Version : at89s52 isp problem

07-26-2010, 09:36 PM
i have made the circuit as shown in link


but my computer does not detects any thing

note one thing more, i made connection assuming it as male db25
i want to know db25 in my circuit is male/female

i have seen in net that male/female db25 pin nos. are in opp. manner

check the link


may be i made opp. connections

07-26-2010, 10:23 PM
I hope you are not using USB to serial ... If yes this will not work. Buy a USB programmer.

Otherwise if ur PC has a serial please check connections . Check using a logic analyzer if signals are being sent on the various lines ...

07-27-2010, 10:37 AM
This is the simple ISP cable form Asif Karim and this is present on http://www.kmitl.ac.th/~kswichit/cheapcable/index.html. Kindly include the source url as it helps other users!!!!!!. As vikas pointed out this doesnt work with USB to parallel converters. If you need a good USB progrmaer try the USB programmer at extreme electronics. Else somewhere there is a URL for a modified USBAsp that can program at89s5X Ucs.....The connector you have used is a male connector.


07-27-2010, 10:50 AM
Is it just me or did the OP say db25 and is being given advice for serial communication??


I would suggest you to check the fuse settings, at times, the factory settings for these uCs are set to internal clock and maybe thats the reason for your problem.

07-27-2010, 02:34 PM
use this , you can omit interface ic 74lvc244


07-28-2010, 09:51 AM
Hi lolman,
The USB to serial/Parallel port converts are both unreliable.....here in India we get BAFFO branded converters which are not genuine and are cheap and useless for most programmers. I have wasted lot of time try to use them to program Uc.