On a different topic, could you please send me a schematic of how to
wire the Hytek to the three pressure sensors?

Mark S.



OK what you need is a five volt supply.

There is a 3 pin chip called a voltage regulator. You put in any DC
voltage up to about 15 volts and it puts out 5 volts DC. You need a
diode in case you wire it wrong and a couple of caps to filter out
any noise. Enclosed is a schematic.

Then wire the pressure sensors as shown to the Hytek data acq.
You can use up to 8 pressure sensors numbered A0 to A7.

There are three active pins. One is 5 volts another is ground and the
third is the analog output signal zero to 5 volts proportional to
absolute press. Zero volts is zero inches of mercury and 5 volts
is 29 inches of Hg or 15 psi.

If you want to see what Tracy's sensors are telling the computer you can
open up the EC2 and connect Tracy's sensors directly to the data acq
using Tracy's 5 volts.

Paul Lamar

Here is some more stuff. If you want timing signals in your capture
file you need to use the HyTek Dx input signals. Those are events like ignition coil triggers and injectors switched on.
It is probably a good idea to use opto isolators for that kind of stuff.
An opto isolator os merely a LED and a photo Tx.
It is mandatory to use them with injector driver and CAS as they switch as much as 12 volts which will damage the HyTek.

"A simple reason? You could use an opto isolator if you were uncertain about what you are doing. If you weren't sure that circuits you wanted to connect to an input were "safe" for your relatively expensive microprocessor, you could connect the microprocessor to the opto isolator as above, and use your circuit to turn the LED on and off. If you did that, then many mistakes you could make would only ruin the quite cheap opto isolator. The Bad Stuff won't jump across the gap between the LED and the photo-transistor. If you've used a socket for the opto isolator chip, always a good idea, then replacing it only takes a moment."


http://www.arunet.co.uk/tkboyd/ec/ec1optoiso.htm

As far as injectors are concerned you can feed the 5 volts output of
the opto to one of the analog inputs and it will automatically record the width of the injector pulse.


It sure would be interesting to find out exactly what e-shaft angle Tracy is firing the injectors.

Paul Lamar