yes 16

Sparks

 

What I was thinking was a multi-channel ADC that has a serial output (rather than parallel), hook it to a max232 then to the PC, on the PC you wouldn't use a terminal, rather you'd write a program (as you would for a microcontroller) to speak to the ADC across the serial port...wouldn't that work? Basically replacing the uC with the PC.

 

It's not as simple as that, a serial ADC can't just connect via RS232, it's a syncronous output, NOT an asyncronous one - easiest way is a micro-controller with in-built A2D, and connect via RS232.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

ok then you will be using two ADC0808 (I dont know if an ADC for 16 analog inputs exists or not?) The third IC will be a microcontroller. The 1st ADC's output goes to the first port of the microcontroller and similarly the 2nd ADC's output to the 2nd port. Next the microcontroller will be controlling the select lines of the two ADCs. There are three select line for each ADC.
If you use 8051 controller probably you can get a ready to use interface for the serial port.

Ok now coming to the programming algo of the microcontroller

START:
1- Send 000 to the select lines of 1st adc and read the analog value on the portA and send it to the serial interface.

2- Send 001 to the select lines of 1st adc and read the analog value on the portA and send it to the serial interface.

3- Send 010 to the select lines of 1st adc and read the analog value on the portA and send it to the serial interface.

4-Send 011 to the.......

5-Send 100 to the.......


6-Send 101 to the.......


7-Send 110 to the.......


8-Send 111 to the.......


9- Send 000 to the select lines of 2nd adc and read the analog value on the portB and send it to the serial interface.

10- Send 001 to the select lines of 2nd adc and read the analog value on the portB and send it to the serial interface.

11- Send 010 to the select lines of 2nd adc and read the analog value on the portB and send it to the serial interface.

12-Send 011 to the.......


13Send 100 to the.......


14-Send 101 to the.......


15-Send 110 to the.......


16-Send 111 to the.......

GO TO START

__________________
Khizer Naeem Mughal
IIUI

 

I agree ..

__________________
Khizer Naeem Mughal
IIUI

 

WoW, you guys are the best !!

So, am looking at getting 8051 Microcontroller, and 2 ADC0808, banging them together. a bit of code and hey presto data logger !!!

I have looked up commercial versions that do the same basic job and the can cost anything from 2000.00 GBP !!! Scarey

I have found a dev board for the 8051 for 22GBP http://uk.farnell.com/1291450/semico...S-C8051F005-TB

And the ADC 0808 for 5.48GBP
http://uk.farnell.com/9486674/semico...TOR-ADC0808CCN

So with the little extras I will need am looking at the sub 100GBP mark, fantastic !

So I'll get those on order with a few bits of stripboard and report back

That is unless you guys come up with any other ideas !

Sparks

P.S. can't thank you guys enough for putting up with me..

 

THe devil is in the details

 

Unless you're in India, I would forget the antique 8051, and separate ADC's - use a PIC with an in-built ADC and a couple of CMOS switches to select your 16 channels (do they make a 16 to 1 CMOS switches?).

Or, instead of CMOS switches, you could use two PIC's with 8 ADC inputs each to give your 16 channels, connect them together using a pin as a serial connection, and have the master one provide a serial connection to the PC.

You'll find absolutely lots of information on PIC's, and it's a far better solution than 8051's.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

Well, suppose am close to India, Warwickshire !

But am going to go down the 8051 route, as in my limited knowledge it seems easier to begin with, and time frames are tight for me..

So on that vein, I have ordered

(8051 proto board)
http://uk.farnell.com/1291450/semico...S-C8051F005-TB

and 2

(ADC0808)
http://uk.farnell.com/9486674/semico...TOR-ADC0808CCN

one

(rs232 Line Driver) (and yes, is a stab in the dark so am ready to be flamed )
http://uk.farnell.com/9664530/semico...UCTOR-MC1488PG

I'm using farnell (http://uk.farnell.com/) as a friend has an account with them)

A few bits of strip board, and an assortment of other goodies...

So once the ritual "you bought the wrong stuff" has been said, any chance I could be cheeky and ask you to point me at the right stuff lol ...

If you feel am asking too much, I appologise in advance, but I sort of backed myself into a corner


TIA

Sparks