have any one notic AT89C and AT89S have some h/w prob.

[manish12]

at89c at89s

i notic that AT89C and AT89S behave diff , for prog which have input and output pins for reading and driving the logic.

number of times , my porg and h/w work ok with AT89C but , not ok with AT89S

 

[nandhu015]

at89c

I had used a lot of both 89C and 89S parts. But i havnt got this problems.

May be use must be missing something.

My guess is isp pins connected to the programmer may behave strange.

Regards
Nandhu

 

[manish12]

one notic

specific about AT89C52 / AT89S52 .

actually , i dont want to think about that the chip have prob, but chip itself do so !


i have a board of universal remote [rf] in which there are number of relays drive by uln2308, and some opto-couplers ,7-seg display.

my ,prog was ok , but chip was AT89S52 , i surprised that the board not work as it should be [as prog] . then i try to check every think start from power s.

after , this i check board with fresh chip of AT89S , but still a prob is there .

at last i use AT89C :- guess , board work fine.

my brother say me about this ,number of times , but i ignore , and i said to his , dont say something wrong inside the chip .

i think he is right ,

 

[ctownsend]

at89c or at89s

you should post a schematic of the board you are using.

Then you will most likely receive some help.

 

[madicalphy]

In comparison with At89c51 and At89s51, beside the point raised in the topic, my finding is slightly different.
I have used both of them many times in different projects.
Even previously I was using At89c51, I download same program with sane hardware in At89S51. To my surprise it was working even well (Fast processing) and shows good results. The Pin configuration is same for both. But At89s51 is fast.
May be I wrong, but it happened more than three times.
:|

 

[amol_shah]

i have used both the chips but both worked perfectly for me, there could be some error in you design, would be better if you post the ckt over here