Subject: EC2 serial port questions
From: Paul
Date: 10/4/2000, 5:23 PM

Perry Casson wrote:


Hi Paul,

Do you still have Tracy's email with EC2 data format spec?  He's lost his
original.

Also on the never ending topic of engine mounts - I'm still undecided on
which approach I'm going to use to build my Glastar engine mount.  I leaning
towards using your plate design as it seems the allow for plenty of room for
the rads underneath and be simple to build  (I think 3/4" for the horizontal
pieces would be a good idea).  Have you built your mount yet?

Regards,

Perry Casson



I am just getting ready to do that know. I need to finish Ken's P-Port stuff
first.  The big washers that sandwich the Barry rubber mounts should be done now. 
If you use the 2002 Barry mounts you need 1/2 inch plate which I think is plenty.
I just got my PSRU from Tracy so that will help. PL


Here is the format & description of data coming from EC2.  I'll take a
look at the display you mentioned.


Serial data is sent as a burst  of data every 100 engine revolutions (once
per second at 6000 rpm)  Serial is asynchronous, 1 start bit 8 bits data,
one stop bit, no parity, 4800 baud at CMOS voltage levels.  +5 V = Mark
state.

Data sent in following order:   (10 bit values are sent as 2 bytes, LSB
first, right justified)

Start Flag  (8 bits)  F0 hex  Indicates start of data group.

1.    O2 sensor output.  fuel/air mixture (10 bits)  255 = stoic. mixture.
      higher = richer
2.    MAP  manifold pressure (10 bits)  841 = 30" Hg. , 200 = 10" Hg.
3.    Air temp (engine inlet ait temp) (10 bits)  511 = 25 degrees C. (curve
      not defined yet)
4.    PGM  current setting of programming knob. (10 bit) 0 - 1023)
5.    Mixture current setting of mixture knob  0 - 1023
6.    Fuel Flow (10 bit) 0 - 511    511 = approx 20 GPH on 13B, 30 GPH on
      20B
7.    Table data in use.  (10 bit) Current mixture correction table entry.
8.    engine speed (10 bit) (1 mhz clocks during 30 degrees of crankshaft
      rotation)
9.    Table address  (8 bit) 0 - 63  Address of current table entry in use.
10.    Staging flag (8 bit) 0 or 1,  If 1 then fuel flow must be divided by
       2 (one injector per rotor in use)
11.    EOX  end of message byte (8 bit) F7 hex


Tracy


 
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