Playwithmyled.com

void calculateHeights( double phi, double theta, double H, double R, double &L1, double &L2, double &L3 )
{
	const double phi1 =   0*pi/180;
	const double phi2 = 120*pi/180;
	const double phi3 = 240*pi/180;

	double x1 = R*cos(phi1);
	double y1 = R*sin(phi1);

	double x2 = R*cos(phi2);
	double y2 = R*sin(phi2);

	double x3 = R*cos(phi3);
	double y3 = R*sin(phi3);

	double nx = cos(theta)*sin(phi);
	double ny = sin(theta)*sin(phi);
	double nz = cos(phi);

	double D = nz*H;

	L1 = ( D - nx*x1 - ny*y1 ) / nz;
	L2 = ( D - nx*x2 - ny*y2 ) / nz;
	L3 = ( D - nx*x3 - ny*y3 ) / nz;
}

This is it for now. I’ll work on the function and get back with it. If you understand more than me, any help is welcome!

After many hours of coding, the version 02 is now out! The application now make the relay in both direction. You can send string from the net to your Arduino, and send string from this serial device to your Web API. I invite you to try it and share your comments!

The summer is over, so much time to type some lines of code. I work hard to make an updated version of my little Integer to serial relay, Insek. Obj-c is not familiar for me, but I like to lern it. I’ve just created a project page on Google code to distribute the files, show code examples, and maintain the development. Currently, I’m working on the communication from the serial device (the Arduino) to the computer (Insek). It’s work, but I have many issue with the the data inputs buffering. Follow the development on Insek project home page. If you can help developing this project, you are welcome!

Well, now that all things are weld together, I’m investigating the programmation. At this time I want to build an app in Objective-C Cocoa for Mac. I’m totally new to it. I work hard to create an app that will act as a Web server that send the data received from an Internet connexion to the serial port of the Arduino. I found some base code that will probably help me doing it. I’ll let you know when I’ll succeed.

All the mechanicals parts and the control boards are now assembled and wired up together. All functions have been tested separately. Now come the time to do some programming. But before I will show you what I’ve already done in my next posts.

Because some pins of the Arduino have a special function, like interrupt, the connections on the proto will be useful to connect thinks to the right pins when I will start programming. I’ll probably use my previous (modified yesterday) multitasking script to be able to control all things at virtually the same time.

Inspired by the Record Player Display projet, I start doing one of my own. A glowing stripe marquee, using an old scanner ripped off. The objective is to learn how stepper motors works, optic switch and resume my experience with logic chips like the 74HC595 shift register. Globally, everything is relatively simple and it’s just a matter of seeking the right information over the internet, and a bit of thinking. The current video is presenting my first test, without the mechanical part. Just the leds and the glowing vinyl stripe moved manually. The last week, I solder the leds and the shift register on an permanent circuit board. It will be fixed on the scanner soon. The optic limit switch works and it will be used to know the reset position of the scanner. The next step will be to assemble the circuit board for the step motor driver. I use a L293D. So happy viewing. You will understand why I certainly make some mistake in my writing.

When I was young, I had two unipolar (don’t know that detail since this week) stepper motors. My pleasure was to connect them together and when I spinned one, the other performed nearly the same rotation. It was a great pleasure to play with. But I finally make one (bipolar) really work today. Yeah! I work hard to understand the motor I got, the MITSUMI M42SP-4. When I look over the Net to find some specs, it’s never what my motor look like. So I guest a four wires bipolar, and I tried it on 5v, safely. Something append, but not correctly. Any bad connections with the L293D? I think not. I found, after a while, that my problem was the Arduino stepper library. I don’t know if I was doing something wrong but it’s look like the stepper function always stimulate both coils at the same time. So I coded an ugly function to recreate the four steps needed, and Bingo! This will make my projet go further.