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Need help on project "PC based robot"

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Krishna Patil

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May 8, 2011
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Shimoga, Karnataka, India
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I'm making "PC based robot" from 8051 projects site.
PC Based Robot (AT89C2051)

I'm not getting desired output.
1) Relays always stays in one state when powered, even if i press keys in software. The software i used is "Without camera interface"
View attachment PC-Based-robot-exe-file (1).zip

2)I have used ULN2003A instead of ULN2003 . Is that a problem ?
**Relays are powered by 12V source and all other IC's by 7805(regulator).

3)ULN 2003 must stay at +5v at normal time and goes to 0v when activated.But it is not happening so , what might be the problem ?

4)I tried to compile project1.vbp but got a error that "videocap.ocx could not be loaded". Actually i don't have Wireless camera. I'll use my Phone's camera over bluetooth as wireless camera. So chose "without camera interface" software.

Here is picture of PCB i have made,
07052011682 (1).jpg


here I have only connected 16th pin of ULN to relay and checking its working when i press "FRONT" in software. If found working i'll buy four relays.

Please help me. I'm near to completion.I'll be waiting for response.
Last edited:

what os version ?

since it is based on com port ,
check your com port first.
is it com1 or com2 ? did you connect it correctly?

if it is com1 and working all right, then
send the commandcode from pc to 2051 , say , your init command etc.
check whether there is any response from 2051.
use hyperterminal .
send the code from terminal .
you will get some response.
I couldn't find hyperterminal in windows 7.

---------- Post added at 17:17 ---------- Previous post was at 17:05 ----------

Sincere thanks for your suggestion . I'll somehow find hyperterminal and try it .

win7 , i think , does not come with hyperterminal.
still you can google for one .
or use xp for such debugging.
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