In SX Microcontrollers, SX/B Compiler and SX-Key Tool, markistuff wrote:

Well Great news, i solved the backfireing problem.  The first few times i had the engine running it was really really rich,  so i fowled up the O2 sensors and it would over compensate and make the mixutre really lean.  i ended up disableing it temperaraly and set the ratio manual.  i connected some POTs to the unused analoge inputs on the board and used that to set the ratio.  and also i had to calcualte out the VE.  i would run the engine steddy at a certain RPM and adjust another POT that would control the VE%, and graphed it all out and made an equation for rpm vs VE.  the engine is only supost to rev to 3600 rmp, but i take it to 4500.  .  today im going to program that into the code.  the VE would be diferent for every engine i belive.  but now i can rev it at any rpm steady and as long as i have the VE set right it runs perfect. no backfireing.  oh i checked the ignition and it was out a tiny bit.  another thing i forgot to compensate for is the time it takes for the injectors to open up, so i programed that in as well.  ill upload the newer version of the code once i get it finished and tested.

So for my setup i think the mosfet drivers im useing will be allright.  the engine is a industiral aircooled 842 cc engine.  but for any bigger aplication it would be a good idea to switch it to the IRL510's.  Im useing High Resistance Fuel Injectors so i dont have to run PWM,  i just used the pulse out command and it gives it full power for the entire pulse width.  but yes if i knew more before i started the project i would have gotten alot of differnt parts.  especialy the sx48,  but its a learning prosses.

William asked what the SR8 port is for.  well when i have time and have figured out all the programing exquations for the fuel injection. i plan on using that as a seiral input output to the computer so i can send and read what is going on inside the engine while its running.

 

I need to find a really fast and effective way to get the engine RPM.  i cant use the count option as it will take to long.  i was thinking  of using PULSEIN, and have it only time the amount of time that the Hall sensor is reading 0.  i think its for only like 20degrees of each revolution.  but if i can get that time then multiply it by the correct constent, the i will beable to get the rpm value.  thats the only way i could figure. unless i have the rpm somehow going into a anloge input and just read that. but im not sure how to do that.  ill give the pulsin a try but any sugestions would be apreciated.

Thanks everyone for your input into this project

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