I am working on tuning a motor. I have no idea what im doing with arduino and I do not have one just yet. I hope to get into this though as I have a project in mind!
What I have found is a device called a "camcon" that takes in a "VVT-i" signal and changes it to a desired output depending on the RPM. In order for this to work for my car I'd have to buy 4 of these devices and I dont think it makes a lot of sense.
These are the specs for the camcon just for reference: http://www.power-enterprise.co.jp/USA/products/electric/camcon/data/installation-english.pdf
This is more a feasibility as well as a hardware question.
I'd imagine a "sketch" could be written that at X rpm (from rpm signal) it an arduino board could take an input signal and increase or decrease it and output it, thus interupting the signal giving me the desired cam angle. The camcon only makes the adjustments per 100rpms so it seems to be a pretty low resolution adjustment.
I even have the wavelengths i'd like to adjust. However, I am not really even sure what im doing.
Here is a link that shows the signals. Scrolling all the way to the bottom there is a list of waveforms.
Waveform 5 has the graph and specs of the VVT-i signal. There are 4 oil control valves that control the angle of the 4 camshafts. 2 intake 2 exhaust. Then they each have a + or - wire. I imagine i'd only need to interupt the + wires.
I am unsure of what "5v/DIV" means. However is this what a PWM input/output could control?
Wouldnt a simple board be able to manage these signals?
My plan would to tap a wire and measure the output to see if the adjustments are actually being made prior to actually testing them on the motor. Also I have 1 camcon on a different motor that I can test the inputs/outputs to see what kind of adjustments I need to make as far as the values. I just need to know if the arduino is capable.
If I'm reading the link properly the control signal is a 5V square wave with a variable duty cycle and a period of a few ms. It would be easy enough for an Arduino to receive or generate that. I have no idea how the duty cycle relates to cam angle but presumably you do.
I'm puzzled that you plan to have four of these. I guess you have four cams, but surely you don't plan to vary the valve timing on each cam separately and independently?
Great! Thank you for the confirmation!
As far as how these waves control the cam angle is a selonoid like valve that diverts oil pressure to a chamber in the cam gear. The chamber on the other side controls the cam from adjusting fully. Actually its easier to describe as a power steering rack assuming you know how that works. I mainly just do not have an understanding of the waves themselves.
I feel they are more complecated than
I watched some arduino videos and i feel the leonardo board has the pwm? Is that what i am looking for? Or does the uno do this 5v square wave?
You are right about likely not needing 4 camcons they are mostly used to change the intake side anyway. I believed these ocvs were sent different signals based on the timing of their bank. (V6) i was thinking they would need separate siignals and the camcon only controls one signal. So i'd need at least 2 to control two different intake cams. However, with this board I was hoping to just have 2 inputs and 2 outputs.
5V/Div means that the scale unit is 5V (The voltage scale is on the left and right edges) . But the text says "(1) Variable Valve Timing (VVT) sensor signal (1)". I interpret this that the signal i comin FROM the SENSORS on the camshaft. Thus i believe it is not an actuator signal. The appearance of the signal conforms that, it looks more like a timing signal than a PWM. Also, actuator signals are often higher than 5V because of the power required.
That does make sense given the "A/F signal" is changing the fuel by 1 wire. They would have to change the sensor wire.
"The CAMCON works by intercepting the signal coming from the engine's camshaft position sensor. This sensor tells the ECU where the camshaft is, and the VVT-i system uses this camshaft position information to set the angle of the camshaft relative to piston motion (called the timing of the camshaft). The CAMCON offsets the signal, causing the ECU to think the camshaft is at an incorrect angle and forcing a correction. Because of this, there is only a certain range over which the CAMCON can adjust the camshaft position, due to the fault tolerance built into the ECU. IF you try to adjust the CAMCON beyond this range, you will go outside the fault tolerance of the ECU and cause a check engine light."