Seeking serial port (RS-232) data acquisition board *suggestions*

I'm needing a low cost board that has a serial interface (RS-232, 9
pin I think). Minimum of 3 analog inputs or two analog inputs and one
digital.
It doesn't have to be very fast, but the digital input could have
frequencies that are as fast as 250 Hz.

Most of the products I've found are in the $90 range. I'm looking for
less expensive.
I'd prefer something in a board format that can be intergrated into a
box.


The lowest price device I've found is:
http://www.dataq.com/194.htm ($25)
And I don't know how they'd feel about me integrating it into a stand
alone product... IE, software and hardware interface.

It's only 4800 baud though. I'd be better off with something that's
9600 baud or faster.


Application:
Automotive data - 02 sensor, rpm trigger (digital?), a few other
things.

Suggestions appreciated!

 

If you only need one or two, this is a cheap as it gets.

If you need more, build it your self. But you won't get below $25 each
unless you make 100s.

Good Luck

 

I can provide u a RS232 data acquisition board at a cost of USD$19.5/-
with your specification. This price is without shipping charges. Let
me know where r u located, for what application r u looking for and
how much quantity u need.

kumar

 

I agree, $25 is pretty cheap. It's 4800 baud though and I'd prefer
some kind of board that I can integrate into a box. I'd pay twice
that if I could find what I'm looking for.

 

Linear's Delta Sigma ADC's can be powered from serial port. Data
sheets show how to control and transfer adc results into serial port.
< $10 each. Demo boards available.

http://www.linear.com/pdf/no_latency.pdf

 

If you're making more than ten of these it will quickly become worth it
to do it yourself. Get a microcontroller with a built-in UART (should
do 115kbps without too much trouble if desired) and built-in ADC. 8
10-bit analog channels for $4 with more digital than you can shake a
stick at. Stick it on a board with a max232. If you can keep the
analog inputs in the 0 to 5V range and really want to keep the parts
count down, get a max233 and do the entire thing with two ICs and no
external passive components.

I know Atmel has some parts which will do this easily and I imagine most
of the competition does as well.

If you have any significant volume they'd probably be happy to hook you
up with something in a different package.