changing this project (Data acquisition system using 8051) to another type of DAQ...need help

do u have circuit diagram for adc0804 and analog mux ic and if i change it does it mean i must change the keil programing for the at89s51....

it is simple just like an adc 0804
u has to share its one channel with other sensors using analog mux
mux ic has addresses
using controller coding u has to change its address noe mux connect that sensor to the adc0804 now read the value of adc
other logic i ssame ansd yes u need to change a little in code
not more just tune the adc routines along with mux addressing

the sensor is looking like a variable resistor strip that can be used in series to another resistor
if it is piezoelectric effect then also can be connected in series to a resistor like a mic connections
http://www.siddiq.com.np/circuits/clap_switch_files/image001.gif

@majoka
thank for your advise i will try what you propose ........

@ redzs08
u can refer to this code for adc0804
http://www.8051projects.net/download-d214-simple-digital-voltmeter-using-8051.html
do analog mux coding by urself

@majoka thanks for the referencing of the circuit and code.......

@ majoka
the project work perfectly now...... the problem is, the delay was to short and it cause the reading to jump high and low.....

i have a circuit for piezo vibration can i use it ..... it will give analog signal can i use it without change the microcontroller code.........

@ redzs08
in which code u want to merge
this has analog output as it can't interfaced directly to 8051
u need adc or op amp
it depend on ur application and ur need

is some have pcb layout for DAQ ..... cozs i'm getting wrong in routing ....

how does this syntax work is to have some delay

void usDelay(int a)
{
	TH0=256-(a/1.085);
	TR0=1;
	ET0=1;
}

pls some hlep.......
how to select what port in pc like com 1/2/3 the code from max232 will or doe it select the code automatically........


how does this syntax work i know roughly but can someone help explain it..

P1=(P1&0xf8)+sensor; 

void usDelay(int a)
{
        TH0=256-(a/1.085);
        TR0=1;
        ET0=1;
}

Yes this code is suppose to generate delay but i am afraid it will not be correct. reason being the involvement of floating point calculations. The following single statement itself will take most of the processing time before it actually generate some delay

TH0=256-(a/1.085);

i suggest you avoid such statements.

how to select what port in pc like com 1/2/3 the code from max232 will or doe it select the code automatically........

redzs08

I did not understand what exactly you're asking.

P1=(P1&0xf8)+sensor; 

well it looks like you are using an 8 channel ADC or something.. the above code seems to set the select bit of ADC. statement is explained below..

P1 & 0xf8 = this part of statement actually clears the 3LSBs of Port 1. without touching the higher 5 bits.
if your port is set to 0x45 = 0b01000101
now 0x45 & 0xf8 (0b11111000) = 0x40
the lower 3 bits will be cleared.
after that this result is added to sensor (variable). e.g if your sensor value is 2 so
0x40 + 0x02 = 0x42

simple?

@ajay
thank for ur explanation it was easy 2 understand after u explain it.........