Well, heres my idea...

I need to monitor certain aspects of my engine.

Turbocharger Pressure/ Vacuum
Oil Pressure
Exhaust gas Temp
Fuel Pressure

Anyway, the way i plan on doing this is using 0-5V sensors, connected to a 8 bit a/d converter with a multiplexor built in. Then send the serial data into a basic stamp, apply the appropriate math, then send the data into a four digit 7 segment display.

My question is this,

1. Does this idea work, (in theory)
2. What a/d converter should i use(needs to have a multiplexor built in)
3. Who makes a four digit seven segment display that accepts a serial input (I need four of them)

Thanks

 

Everything you mention is possible and shouldn't be too hard.

As far as an AtoD i'm not sure how fast you want to sample. If you go to Digikey.com they have a great search engine with a huge selection.

Instead of 7 segment LED's you should look into LCD displays. You can buy ones that use serial input - again digikey will have a ton to choose from. You also might try http://allelectronics.com/ They have less selection but cheap prices. If you have a bit of money to spend Amulet Technologies has easy to use graphical LCD displays that run off RS232.

If you're planning to get into electronics for your car Its probably worth your time to learn about microcontrollers instead of using a basic stamp. Your average microcontroller will be significantly faster than a Basic Stamp and microcontrollers arn't that much more complicated. You also can buy microcontrollers with built in A to D's. Nigel has some tutorial to get you up and running with the PIC microcontroller.

If you are just looking for a simple way to display your data there are ICs designed for multimeters that are AtoDs that drive LED displays for a one chip solution to your problem.

Brent

 

Well, the only reason im using a basic stamp, is because i have one. Im not to concerned with speed, so that shouldnt be a problem. I decided to go with the 7 seg displays because, i have to fit all this into a din slot(180x50mm). I need fairly large displays, so it doesnt take long to read. The leds allow me to put very large digits in a small space, though it will be a pain to wire.

Thanks for your help

 

Actually the PIC comes with 10 bit A/D onboard, on enough different pins that you wouldn't need a multiplexer.

I have done a graphical LCD display for my ultralight. With the exception of the tach, all the interfacing is fairly straightforward.

I have no love of Stamps. It's horrifically slow yet expensive. With the PIC's pins pre-wired, a lot of versatility is lost. Given that the PIC was DESIGNED with on-chip program flash, it's insane to ignore the huge existing flash and build it into a part like that and charge 15x more for it, when all you're saving seems to be the need to wire in a crystal.

There are C compilers out there for PICs if, like me, you don't want to work with assembly.

 

im working on a similar project myself and i'm finding that the use of a ca3162 (a/d) and a ca3161 (7 segment display decoder/driver) works pretty well. its only an 8 bit but for some applications 8 bit is all you need. youll be able to drive 3 7 segmnent displays. :twisted:

__________________
Reality is an illusion.

 

You could use ADC's from Maxim: the MAX113 & MAX154 are 4 chan, 8-bit:
http://pdfserv.maxim-ic.com/en/ds/MAX154-MAX158.pdf
http://pdfserv.maxim-ic.com/en/ds/MAX114-MAX118.pdf

Maxim also makes the MAX7219: it drives 8 common cathode LED displays per chip, interface is 3-wire serial.
http://pdfserv.maxim-ic.com/en/ds/MAX7219-MAX7221.pdf
JB

 

ok instead of using all these a/d just use a dvm and calibrate to fit your scale. u can use a ICL7106 for LCD display or a ICL7107 for LED display. :evil:

__________________
Reality is an illusion.

 

rip the digital dash out of a 88 caddillac brougham. then apply sensors and recalibrate it for your application.

 

For the stuff you are trying to meter, if you are racing, speed on your gauges is ESSENTIAL. These factors can change in a matter of milliseconds. as for your desplay, you would be better off with an lcd screen. try buying one from APC. my race team uses them and they are BEAUTIFUL. i love them. they are bright and easy to read. but if you are really into trying to do it yourself, then use the microcontroller so that you will have that speed and efficiency that you need for racing. if you arent racing, then you dont need any of this, unless you are a mechanic.