Hello World!. This is my first brave attempt to post here after combing through the forums and searching through the vast sea of google gathering as much info as possible. If I am posting this in the wrong thread, please let me know and I will move it..
I have bought an arduino and a raspberry pi and wanted to take a stab at implementing some ideas I have, but I have one large downfall.
I have little to no experience with electronics. I program and admin network equipment, telephone switches, servers, desktops, radios, etc.. I also have some minimal Java coding experience. But, I do NOT know much about electronic components.
I have experience wiring 12VDC circuits up on older race cars (simple ignition, switches, fuses, coils, lights, batteries, kill switches, and tachs from the coil) and understand Ohms law from the perspective of figuring how much resistance, what size wire, what size fuse, how much current draw,etc..
However, when it comes to capacitance,inductance, transistors and the likes of stuff like that...I will be the first to admit how ignorant I am.
I have a basic idea of what they do, but by no means know how to apply them in the right place and why to choose one model/rating over the other. Which I why I wanted to start here, in a community like this, with guys and gals around the world of all levels of experience giving pointers and teaching others.
[u]Brief overview of project:[/u] I have a Harbor Freight knockoff of a Honda Clone single cylinder, 4 stroke, gas engine. It gets its spark from a magneto circuit (no battery) and is shut off by a kill switch on the shroud of the engine. I have done research and cannot find what kind of ignition it actaully has (CDI, points, etc..?) I was going to find a coil from a junk engine and look at it more closely to see how it works. I was wondering if there is a way to pull a signal from the low voltage side of the coil, instead of the spark plug.
I want to start out with a proper and safe way to pickup a spark for this engine and turn that in to a safe and clean pulse to feed to the Arduino.
I've read many posts using different chips and read the sport devices article, but am unsure which on to use and why? All of these require wrapping a wire or clamping around the HV spark wire. http://www.sportdevices.com/rpm_readings/index.htm
End the end, I want to use count elapsed time between pulses as outlined here: http://tronixstuff.com/2011/06/22/tutorial-arduino-timing-methods-with-millis/
So my biggest unknown is what kind of circuit to use to get the ignition pulse.
To make matters worse I don't have access to an O-Scope. Are there any cheap scopes out there, or is there a cheap way to make one for the raspberri pi.
I am sorry for my ignorance and wall of text, if anyone has built a circuit for something similar that could share their design with me.