wb lcd display

[Peter Gargano]

bcroe at juno.com wrote:
> 
> I just got one of those KC5300 Fuel Mixture Meter Kits
> from Jaycar today.   Looks like a pretty reasonable
> assembly.  It could be used to display the WB Vout
> in digital format, if someone is up to writing code for
> the PIC 16F84.  Would save building something from
> scratch.  Probably needs some kind of voltage scaling
> at the input too.

Remember that the code is freely available, & should be easy
to change the table(s).

Also, the biggest limitation of the kit is that it's just
a display that is updated about 2.5 times a second. No
digital output for logging. Nor would adding the code for
an RS232 software driver (and a transistor for driving the
physical RS232 interface) be adequate because the A/D
conversion is too slow - at least IMHO.

> As originally designed, it used a Bosch EGO sensor.
> The idea that this is a wideband unit is really a stretch; I
> would have little confidence in the displayed value outside
> of 13.5:1 to 16:1.  It is a big step ahead of those 10 LED
> displays you connect to a typical NB sensor.  It is just a
> display; there are no sensor support circuits of the type
> provided by the WB project.

Now, if they'd used an SPI A/D chip, and the RS232 H/W driver,
the unit could be a nice interface to a PC for data logging,
as well as the real time display it is.

Peter.
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