BLACKBERRY TRACKBALL

[atomicareprise]

can i use the blackberry trackball for my psp phat?

how will i know which solder points am i going to solder on?

thanks..

[alentris]

can i use the blueberry trackball for my psp phat?

OH MY GOD!!!!!!! XDXDXDXD It's a "Blackberry" !!! that's got to be the most funny thing I've heard in a long time. But really, It would require Analog 2 Digital, and l0rdnic0 did this a while ago.

how will i know which solder points am i going to solder on?

It's called a multimiter... use it, love it.

[atomicareprise]

sorry yeah its the blackberry...

i made you funny huh...

so do you know where the solder points?

[alentris]

i made you funny huh...

I laughed for a good couple of minutes on that one...

so do you know where the solder points?

I don't know where the tut is, but l0rdnic0 did this a while ago... You could try pm'ing him.

[ryan0]

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.
NiK

TL;DR I hope you guys think my English has gotten better since last time I was here a few months ago.I went to school in London for a few months and I've been reading loads of books and listening to Stephen Fry

[EliteGamer83]

This project sounds vaguely similar to the PSP mouse project. I've never bothered to read anything in that board but try looking up some threads in there or the Search feature, you may get some tid bits of helpful info. But yes this is pretty much the PSP mouse project but just integrated into the PSP itself. 

[kink192]

nico had a trackball that didnt put out analog or used infared at all, his had two switches that would be set ff my the trackball. they were supposed to sell them at the shop but that never happened, they were also supposed to have a breakout board so you werent soldering onto .5 milimeter slits of copper, alas no results there, i was planning on using one in my psp since i play lefty i use the analog to aim. nikolai, im somewhat interested in doing this to my one ps2 controller, i dont have much room inside since it has my shocker mod but if you can send me a parts list via pm ill gladly give this a shot.

[ryan0]

nico had a trackball that didnt put out analog or used infared at all, his had two switches that would be set ff my the trackball. they were supposed to sell them at the shop but that never happened, they were also supposed to have a breakout board so you werent soldering onto .5 milimeter slits of copper, alas no results there, i was planning on using one in my psp since i play lefty i use the analog to aim. nikolai, im somewhat interested in doing this to my one ps2 controller, i dont have much room inside since it has my shocker mod but if you can send me a parts list via pm ill gladly give this a shot.

I have about 10 pages of notes on the subject of IR fequency input to analog output that I could send you,but they are in French.I can translate them for you,but I don't know some of the names of the parts in french (writing the post above was hard as it is),so be prepared for the odd french word here and there.

[insomniadmx]

NikolaiK's explanations of the trackball's operation are very good. I'm going try to elaborate a little and save NikolaiK a little time in translating (I'm not that great at explanation so bear with me).

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:

http://www.ontrak.net/pwm.htm

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.

http://www.4qdtec.com/meece.html

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.

[Jumbo]

There was a track ball that mike was selling that was digital allowing for PSP use, but im not sure when the shop is coming back if ever...

[ryan0]

NikolaiK's explanations of the trackball's operation are very good. I'm going try to elaborate a little and save NikolaiK a little time in translating (I'm not that great at explanation so bear with me).

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:

http://www.ontrak.net/pwm.htm

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.

http://www.4qdtec.com/meece.html

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.

Thank you,you saved me so much trouble and your explanation was great





For the others:
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.