data acquisition card using c8051f040-tb

hello sir..
iam posting my ckt diag for d/ac card pls do the needful....corrections... also the ports have 2 be connected 2 the 96 pin connector

thanks for your PM sorry anyways!

hello ajay!
well... we r required 2 write program 4 accessing the different devices i.e d/ac ac/d digital i/o etc from the data acquisition card uc.. u had seen from our design that we r planning 2 interface 8 devices with the card.. how can we program 2 keep the devices off ...i mean we r using 3:8 demux 2 obtain select lines 4 the devies... so they can be accessed by 3 addrs lines.. but how 2 keep them all off... 4om our design 1 device will always be selected i.e 000 or 111 state always exist at extremes..
another doubt is that we r using quad opamps..instead of the buffer ic shown in the pic i send u.. form offset adjust we planned 2 put a 1k pot at each inv terminal.. now all the 4 pots have 1 terminal at +15v and other at gnd.. so will they not be in parallel and hence resultant resistance go down 2 250ohms ??? so how 2 solve it??
also programming is a bit problem cause i am from electronics and programming jamta nahi

well... OK! all i can say is good..
for keeping all the device off.. you can simply connect the enable pin of demux with your controller to control it. so if demux is disabled all devices will be off.. so whenever you want to select a device.. simply send the selection data and enable the demux this will give surety that the correct device is selected and is on..

Regarding you doubt.. i seriously cannot image your circuit. Please ask your guide to provide you with a good software to make schematic. I am really sorry Suraj, its very hard to understand the schematic you sent.
Also regarding programming i must say.. being electronics means being all-rounder.. we are the only people who can do everything so you must learn programming its necessary.

dear ajay..
errr u missed out 1 doubt of mine... i'll repeat it again... we r using a quad opamp...4 buffering purpose.. we r giving input 2 the noninv terminal..and connecting the inv terminal 2 1k pot...which has one end at the +15v and other at gnd.. for offset adjust... now as we r using quad opamp.. 4 such cases will occure and any how.. all 1k pot will have one end at +15 and other at gnd.. so theoritically speaking all will appear parallel 2 each other and resultant pot value will be 250 ohms.. so how 2 solve this problem???

yes i know.. suraj but the thing is.. i cannot imagine the circuit.. like that.. so advised you to ask your project head to get u a good circuit desing software.. so that u can make a better circuit...

for your doubt, try to use one pot connected to all opapms.. that might solve your problem.. I am really not sure... coz unless you see the working.. you cannot say what is going to happen.. as.. some errors are logical.. not theoretical