Tuesday, April 27, 2010

trackball for psp ?

aku tfikirkan pasal trackball phone CSL dengan Blackberry ni dah dekat dua hari..ok tak kalau buat ganti sebagai dual nub..?

Bebola Jejak (trackball) ialah peranti input yang menjalankan tugas yang sama seperti tetikus. Prinsip operasi bebola jejak ini juga sama seperti tetikus. Rupa bebola jejak ini sama seperti tetikus apabila diterbalikkan. Bola getah berada di bahagian atas bebola jejak.
Pengguna perlu memusingkan dengan tangan bola getah yang sebesar bola snuker (snooker). Penuding (pointer) akan digerakkan pada skrin monitor. Biasanya bebola jejak akan di gunakan jika tiada ruang di atas meja untuk menggunakan tetikus.
Dulu komputer buku banyak menggunakan bebola jejak tetapi sekarang kebanyakannya telah menggunakan pad sentuh untuk menggerakkan penuding pada skrin monitor. Penuding akan bergerak mengikut bahagian pad sentuh yang disentuh oleh pengguna.

trackball ni banyak digunakan kat mouse,keyboard pc dan alat gps..kat phone pon ade,macam model blackberry or CSL..nampak macam best kalau pasang kat psp..heheheeee..kat acidmods dah ade yang wat..lordnico rasanya..tapi untuk wii

ni ar gambor wiimote dengan trackball..

untuk tau boleh buat ke tak..aku tengah dapatkan trackball CSL ni..So stay tuned~payah nak dapat mende ni..da kontek supplier tapi sume kate takder..

ni sedikit info dari acidmods yang aku dapat

"I can walk you through it,but there's pro's as well as cons,
here we go:

Trackballs have an x axis and a y axis.
Attached to these axes are small spindles with slits in them.
On one side of the spindle is an infra-red led,on the other side is a phototransistor.
When you rotate the trackball in a certain direction,the spindle spins.
The infra-red light passing through the spindle's slits while it is spinning creates waves in the infra-red light,the phototransistor picks these waves up and sends them to a chip programmed to process these signals,and output an analog signal to the motherboard,which then makes the mouse move on screen etc.
The frequency of the waves in the infra-red light tells the processing unit how fast and more importantly *when*,you are moving the trackball.

To overcome this problem,you need to programme a PIC to convert the infra-red light waves into analog outputs correspondent to the resistance of a psp analog stick.

My personal thoughts are that this mod is not worth the effort.....not one bit.Here's why:

Imagine trying to play a game where you run around with the analog stick,furiously swiping the trackball forward,transforming normally smooth movement into a choppy arthritic limp.Or any situation where you are required to hold the analog stick in a certain direction.

I know all this because I did it o a ps2 controller before,on the right analog stick,but that's because there isn't any games that require you to hold the right analog in the same position constantly,so it was great for fps'.
Give it a shot on a controller,it's worth the effort.
I'd give you my code but I lost it when my hard drive crashed,but I could certainly help you.

"The speed at which the wheels (x wheel and y wheel driven by trackball) are moving is proportional to the frequency that the phototransistors pick up. The speed is our desired unit and the frequency is our given. The frequency that the phototransistor picks up is a square wave signal of logic 0 and logic 1 (when it detects light and when it doesn't). Technically, this is a pulse-width modulated (PWM) voltage signal. Since PWM signals are composed of only the maximum and minimum values (square wave), the ratio of the length of time when the signal is at maximum to the length time of the period (or what's called the 'duty cycle') is used to describe it. Basically, if you have a PWM voltage and want to make it an analog voltage, just take its mean. This can be accomplished in-circuit with low-pass filtering. Check out some detailed info on low-pass here:


I was a little baffled at first though, how can you figure out which direction the wheels are turning in (in other words, if the wheels' speeds are negative)? Apparently, trackballs use two or more phototransistors per wheel. Check out this site for more information on that.


The thing is, you'll probably want to check which of the two phototransistors goes high first with some interrupts. (and you'll definately want to have this checking to happen in the circuit before signal goes through the low-pass filter.)

Hope that made sense and/or helped."

"A trackball that uses switches would be crap in comparison to an standard one,because one with switches cannot be rotated fully around like an standard one.Remember we are not converting analog to digital,we are converting analog to analog (kinda).You are simply translating the dips in resistance of the trackball (analog) to the solid analog signals of the analog stick (also analog).
If you're any good with PWM you could do this no bother,I could give it a shot,but I'm no good with PWM."

"Trackballs can be very difficult to handle in terms of the electronix and signals.  When we did the Wii trackball remote we were able to find the trackball used in blackberrys from Mouser.com, that track ball wasnt very traditional in the sense that it was just four switches that made contact when rolling the ball in the respective direction.  with that track ball it would click click click when you rolled it so it was like a low frequency tapping of the direction when hooked up to the controller.  Esentially that low frequency clicking was too slow in order to use the track ball in any real games, its sensitivity was not enough to make it a real usefull mod. So from that we would make a pic program that increased the sensitivity of the ball however each click would be much courser movement which gets rid of the sensitivity one desires in gaming.

The wii mote directional pad was well suited for that particular track ball as it was a digital input.  The Analog controls on a 360 controller wont be as well suited as that track ball was really a digital input device.  Doesnt mean it cant be done, just means you wont get any analog action from that trackball, it will either be full on or off.

If one was to attempt this mod I would suggest finding/hacking a track ball like a mouse that will give you signal that is proportional to the speed that the ball is rolling.  I am not sure if a mouse will give you that signal without some hacking of the control electronix, but it is something you could investigate.

Remember also that the analog sticks are 2 potentiometers with spring returns, which means that when the anolog stick isnt being pressed the x-axis and y-axis signals will be in between +V and ground.  For example if +V is 3v and gnd is 0v, when the stick isnt pushed in any direction the signal on the x and y axis will be 1.5V.  When it is pressed up, the signal would be 3V on the y-axis and 1.5v on the x-axis.  If it is pressed down the signals would be 0V on the y-axis and 1.5v on the x-axis.  So more than likely a level shift in your signal or crafty ground connection will be required."

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