CDI and programmable Ignition in Oz
Rene Van Den Bedem
rene.van_den_bedem at fujitsu.com.au
Thu Jul 16 05:30:13 GMT 1998
I have this on my Car with LPG for 1 year (160KM/day), runs excellent,
after I sorted out teething problems (12V noise & PIC overheating).
The only drawback, from a Software Developer's point of view, with this
system is that it is not interrupt driven.
If you want a copy of the schematic & article I can email you.
My experience for setting it up is at
http://www.deakin.edu.au/~reneb/index.html or mirror
http://www.fortunecity.com/underworld/virtua/592/index.html
I emailed Tony Nixon to discuss his ideas for a future enhancement. He
said, quote"
I started to develop a new system based on the PIC 16C74 with
external EEPROM. I was hoping uChip would hurry up with some of their
new chips so that the system could be made as a single chip solution.
It used only 6 keys for programming and used a 2 line LCD display to
show the settings. These were set up in a menu fashion and you can
use the keys up/down/left/right etc to select and change the
settings. This could also be done while the engine was running as the
software checked your input for errors.
It also had a virtual distributor adjust, whereby you could use the
keyboard to 'move' the distributor +/- 5 degrees. I could do this
upto about 9000 RPM (I think) because the software had a 16uS
resolution with the chip running at 16MHz. Not bad when you consider
it had a lot of other house keeping and maths to do.
It had crank/distrubutor select, all of the original PEI settings but
with 3 stages of advance that allowed +ve or -ve settings on each.
It also had multi spark capabillity if selected. I also programmed an
auto scaling analog vacuum advance function because the '74 has an
on board A2D. Other things are rev limiting, over rev indicator
(shift light) and probably needs other things I haven't thought about yet.
Farnell has a nice Gear Tooth sensor that would be ideal as a crank
sensor. You can use just about any MAP sensor for the vac adv. I was
also trying to find an alternative to the MJ10012. SGS Thompson make a
coil driver which can be driven directly from a uC, but thay are too
hard to get in Oz. Some new PIC clones are out that process at 50MIPs
but I don't think they have a lot of hardware goodies.
Some other issues were mechanical mounting of sensors etc. which I
don't think will be much of a problem. Designing electronics much more
suitable for an automotive environment, may be more of an
issue, but it may be a bit out of my league. I haven't had much experience
here. I think the PEI gets by on luck sometimes.
I have had some enquiries about a system like this so I think there
will be a demand for it as long as the project is kept very simple.
It would need to be easy to program and assemble and relatively easy
to install. Above all, it should be cheap. If they could be sold as a
kit for around $100.00 - $150.00, I think they would do well.
Thanks for the web comments, it was my first try. I started PicNPoke
in an effort to teach myself WinDoze programming. I didn't think it would
get as popular as is has. That's the main reason I haven't had time to
do anything else." unquote
Hope it helps,
Rene.
At 19:52 15/07/98 -0700, you wrote:
>Ants wrote:
>>
>> I went and had a look at the programmable ignition kit at Jaycar. it cost
>> $65.00 AUD. It has 2 programmable ramps. It's very basic. I have ordered
>> the magazine article in which it first appeared. Maybe we can modify to
have
>> more programmable points.
>>
><snip>
>Interesting, I've emailed Jaycar two or three times requesting purchase
>information....it's been 1.5 months and still no reply.
>
>Contacted the gentleman who wrote the PIC program (Tony Nixon), inquiring
>about motorcycle mods...He stated the program in its present form (with two
>tables) used all but 4 bytes of ROM.
>
>Unless the code was very poorly written, which I doubt, some form of
external
>data space would be required to enhance the present program. Perhaps an
>external eeprom handling the data tables would be an answer.
>
>
>Bob Cuda-65 - Angels Camp, Calif.
>cudabob at workmail.com
>http://www.goldrush.com/~rhuish/
>
>
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