Injector Duty Monitor

[steve ravet]

rauscher at icst.com wrote:
> 
> On this subject, what is it that we really want to
> measure? Duty cycle or the pulse width?

Duty cycle, right?  The time available to inject fuel decreases with
increasing RPM.  So (for example) a 1 ms pulse at idle, every 20 ms is a
lot different than a 1 ms pulse at a higher RPM every 5 ms.  Just picked
those numbers out of the air. Don't think of it as PWM, where the
frequency never changes.

> 
> The two designs presented (B. Bowling and C Hack),
> are nice. But getting access to a PIC programmer
> can be a problem. JDR carries a bunch of PIC's, and
> the OTP 16C56 can be had for $4.50US, not bad. A
> AT89C2051 w/flash is $7.00US, plus Christian's
> design reads out on an LCD screen, nice again.

It's Georg's design, if you're talking about pwmeter.zip.  Sounds like
the whole thing could be built for $40 or so.  I'd be willing to buy one
if someone can program the atmel parts, and if someone can modify the
program to display both on time and duty cycle.

--steve