Hi
I am brand new to Arduino(just got it today ).
My first project is, building a Dyno-controller, for my engine brake, based on the Arduino Duemilanove.
And a big watercooled diskbrake, a torque arm with a weight cell/amplifier that produce a 0-5v output.
Unfortunatly i have no pictures yet.
My plan is to take it step by step, and hopefully learn along the way.
My first task is to get a stable rpm counter, via a halleffect sensor.
Then produce a open loop PWM output, to control a fast acting valve(that control the brake), so that i can keep the engine below a chosen rpm(target),
To determine the target value(0-15000), my plan is first to use a potmeter, just to get started.
But i plan to make a feature later, so i can rev the engine to any rpm, and press a ”hold this rpm” button, then have a ”+” and ”–” button, to raise or lower the target rpm by 100, at each push on the button.(if any of you a great idea for that i will be more than glad to try it out now anyway )
And i will need an ”auto-sweep” function, that starts at say 1000rpm, holds it there for 1sec(to stable the weight cell), then raise the target by 100rpm's, for each following sec.
Until the rpm drops below 1000rpm's again(or another value), to tell the auto-sweep is over.
Later i will have a software, that will log the values, of the weightcell(nm), and calculate the hp from that.
I was thinking to send the value, to the software, just before every raise of rpm.(as the weight cell is most steady, at that time)
I also plan to use a display, i was thinking 2x20 lines, that can tell me the target rpm, and realtime rpm on the first line, and NM and HP, on the second line, so that i can read the realtime values without any pc plugged in.
Even later than this i will try to make a weather station, to compensate for barometic pressure, humidity and temperature.
But my first task is to get to work, so i can get some readings out.
Not to get the dynofigures, to brag with, at the gasstation, but for adjusting and mapping the engine.
That means that i will start with the revcounter.
I have been searching this forum and found some fine examples, but some of seems to be very accurate and complicated?
This one for example: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1274834441
Seems to contain alot more than what i need?
And this: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1281925297
This one looks like it could work for me to, but i was hoping to go open loop?