Building 3cyl 2-stroke cdi

[bojane]

Using the stator AC input too charge the cdi ignition.
Tach signal from the existing trigger (3 teeth)
Small battery for controller.

Functions:
Sequential ignition
Cop
Launch
Electronic reverse
Tps

Figuring on which controller too use , any suggestions ? Thought of arduino mega but seems to have a bit slow CPU


/ Anders

[ivan141]

AT32UC3C2512C

I'm no expert on selecting EFI processors, but this is one I ordered to mess around with.
It is aimed at automotive peripheral subsystems and has a shitload of features on board.
Native interfaces:
USB
SPI
I2C
CAN
LIN
Ethernet
11 12-bit ADC channels
2 DAC channels
66Mhz AVR core

[bojane]

That looks like a good processor with a lot more omph

Which way is the best route to go regarding buing proto board or just the processor ?

If buing the frescale. Is it less work to hack the FreeEms code then write my own ?

Thank you
Anders

[ivan141]

I suppose working from an existing codebase might be easier than starting from scratch.
You just have to watch out that modifications dont end up costing you more time than building from scratch (As is sadly often the case in my dayjob as automation programmer).
Last time I looked at the FreeEMS code it looked modular enough to use, but you'll have to have a look for yourself.

If you need a prototyping platform there is one available for the Freescale MCU, it is widely used for one-off builds,
have a look in the Hardware Dev section, I believe it's called a TA card.
There is also a modular prototyping platform for almost every Atmel processor in production, but you'll have to buy it from Atmel.

[bojane]

Yep started looking at the code, my god it must havet taken a truck load of time writing all that ! Seems written in a modular manner Not used to work in multitreaded big projects thou. So will take me time understanding it

I'm also working in automation at a big company, not so much coding thou and the structure is quite differrent (Abb 800xA)

Think I will try building my own board. It's so few input/outputs thats needed .... Really excited starting this project will ask a lot of stupid questions during the process. Hoping that you can bare with me

Regards
Anders

[baldur]

I built a controller for my old Polaris Indy 650 RXL using an Atmega8535 chip a couple years ago. Single channel though, not sequential. What I wanted at the time was programmable advance curve in a unit that was plug and play compatible with the stock CDI box which runs the 3 coils in a waste spark configuration.
I have since removed the HV magneto part and am using an MSD 6AL 12 volt CDI but this board still controls the timing.
I experimented with electronic reverse but found it wasn't practical on a piston port engine which doesn't have enough torque at idle to reliably perform the reversing operation.
What is your application?

[bojane]

Cool project Those rxl had a really nice sound. Still get a chill when I hear them run

I'm also looking for a turn key solution. Have ordered diods, thyristors and caps for the ignition part. Will use lm1815 for the trigger circuit.

Think I will use Texas tiva dev board. Cheap powerfull and easy programming.

Will mount it in a Yamaha sxr 700, The stock ignition retards the timing heavilly above 9000 rpm.