Bongofish
November 15, 2019, 09:48:54 PM *
Welcome, Guest. Please login or register.

Login with username, password and session length
News: You may have to login twice the first time,  but we don't know why - Erm I mean it's a security thing yeah that's it - security.
 
   Home   Help Search Login Register  
Pages: 1 ... 7 8 [9] 10 11
  Print  
Author Topic: jittering pointer  (Read 103789 times)
bernard
Administrator
Hero Member
*****
Posts: 2590


pato mania


View Profile
« Reply #120 on: June 20, 2011, 02:52:58 AM »

Sadly, I believe there is not a single chance that a pointer from another brand (like those that have batteries) will even remotely start to work with the wacom tablets.
Logged
Pesho
Hero Member
*****
Posts: 275



View Profile
« Reply #121 on: June 20, 2011, 09:30:18 AM »

Sadly, I believe there is not a single chance that a pointer from another brand (like those that have batteries) will even remotely start to work with the wacom tablets.

No no, of course it wouldnt work! I meant the whole set - non-wacom pen AND tablet. As written on wikipedia on active vs. passive tablets:
Quote
Active tablets differ in that the stylus used contains self-powered electronics that generate and transmit a signal to the tablet. These styli rely on an internal battery rather than the tablet for their power, resulting in a bulkier stylus. Eliminating the need to power the pen means that such tablets may listen for pen signals constantly, as they do not have to alternate between transmit and receive modes, which can result in less jitter.
Logged
bernard
Administrator
Hero Member
*****
Posts: 2590


pato mania


View Profile
« Reply #122 on: June 20, 2011, 09:32:34 AM »

Ah! Smiley   I understand what you mean.  Sorry, me slow.

Yeah, sounds credible indeed.  Wanna try them?
Logged
Pesho
Hero Member
*****
Posts: 275



View Profile
« Reply #123 on: June 20, 2011, 09:40:51 AM »

Yeah totally, sadly i dont have access to one of these (only a Wacom Volito 1). Undecided I used to have an old UC-Logic tablet but i have noidea where it is. That's why posted the reply here, in case there is someone with a battery powered tablet that could give it a try...
Logged
bernard
Administrator
Hero Member
*****
Posts: 2590


pato mania


View Profile
« Reply #124 on: June 20, 2011, 09:49:07 AM »

Wacom Volito 1 ! -- oh wow!  These are USB, right?
Logged
Pesho
Hero Member
*****
Posts: 275



View Profile
« Reply #125 on: June 20, 2011, 10:00:44 AM »

Yeah, it's USB  Cheesy I've had it for many years. Been doing rough tests with it and my laptop's 12.1'' screen and there isnt too much jitter except for only certain areas - the area where the LCD screen's PCB is folded gets no signal at all (i just used the screen as it is on the laptop with the Volito shoved behind it). Jitter also increases in places where there is plastic or tinfoil on the back of the screen (there is some sort of tinfoil tape at the top where the CCFL goes) where the jitter gets progressively worse as the pen goes more into that territory. Distance from the tablet also seems to be a factor, since as you get farther away, the jitter increases much more than if you have it touching the screen.
Logged
monet
New Poster
*
Posts: 6


View Profile
« Reply #126 on: November 11, 2011, 04:18:45 PM »

I have this jitter right now, everything is fine on the upper part of the screen no jitter at all, the jitter is about an inch from that long pcb on the lower part of the screen, will try to shield and ground it. aspire one happy and intuos4 m.
Logged
monet
New Poster
*
Posts: 6


View Profile
« Reply #127 on: November 15, 2011, 12:05:19 PM »

Just made a scary mistake yesterday, wrapping the pcb with aluminium foil and the screen goes totally white, pull up the battery immediately, and it's working again Smiley. Wrapping the pcb with paper first and then the foil, I still have the jitter, a small improvement toward the lower part of the screen about 0.25 less jitter space measured from the lower edge.
Logged
Drewid
Administrator
Hero Member
*****
Posts: 2290


wielder of electric crayons


View Profile
« Reply #128 on: November 15, 2011, 02:52:13 PM »

You also need to connect the foil to an earth (ground) connection on one of the PCBs.
Logged

Games work site:  Drewnorthcott.co.uk
Personal site: Bongofish.co.uk
Tigertron
Jr. Member
**
Posts: 52


View Profile
« Reply #129 on: November 15, 2011, 08:50:25 PM »

You are the second person I have seen that did not realize you must insulate the foil from the board. I'm not sure why this isn't apparent.

But for anyone else wrap you board in plastic, paper or tape or some other INSULATOR and make sure the foil does not touch any part of the board. Ground to a ground on the power supply. One ground only. Another trick to try is double shield by wrapping that grounded sheet of aluminum with plastic, paper or tape and then another grounded foil sheet. The small space between the two acts as a rf trap.
Logged
monet
New Poster
*
Posts: 6


View Profile
« Reply #130 on: November 16, 2011, 05:41:12 AM »

Smiley I thought because it is aluminium then it's ok but it is not (I am using cooking aluminium foil), and thanks for the double shield I will do it today, I think I need to make a plastic housing first and double wrap and ground them.
Logged
sekopasa
New Poster
*
Posts: 21


View Profile
« Reply #131 on: December 22, 2011, 10:52:04 AM »

What happens if you cover your board with plastic/paper, and than folio but dont ground it, could it damage the board?
Logged
bernard
Administrator
Hero Member
*****
Posts: 2590


pato mania


View Profile
« Reply #132 on: December 22, 2011, 06:53:35 PM »

Not grounding a shield reduces the efficiency of the shield.  But I cannot explain why, maybe someone else knows what happens exactly.
Logged
sekopasa
New Poster
*
Posts: 21


View Profile
« Reply #133 on: December 22, 2011, 10:19:55 PM »

Is there any build here made with laptop screen and insulated and grounded as stated?
Logged
Dragon
Full Member
***
Posts: 121



View Profile WWW
« Reply #134 on: January 07, 2012, 12:32:25 AM »

I've recently posted a new tool to help in diagnosing jitter and monitoring for small changes in jitter.

Another interesting thing from Wikipedia:

Quote
Equipment sometimes requires isolation from external magnetic fields. For static or slowly varying magnetic fields (below about 100 kHz) the Faraday shielding described above is ineffective. In these cases shields made of high magnetic permeability metal alloys can be used, such as large crystalline grain structure foils or sheet metals of Permalloy and Mu-metal,[2] or with nanocrystalline grain structure ferromagnetic metal coatings.[3] These materials don't block the magnetic field, as with electric shielding, but rather draw the field into themselves, providing a path for the magnetic field lines around the shielded volume. The best shape for magnetic shields is thus a closed container surrounding the shielded volume. The effectiveness of this type of shielding decreases with the material's permeability, which generally drops off at both very low magnetic field strengths, and also at high field strengths where the material becomes saturated. So to achieve low residual fields, magnetic shields often consist of several enclosures one inside the other, each of which successively reduces the field inside it.

I would think the magnetic fields from monitors would be under 100khz since the monitor refresh rate is usually around 60hz, so the aluminum or copper shields usually used shouldn't be too effective, if what's written above is correct.  Yet they generally do seem to be effective, so I'm not sure what to think.  Maybe the above would be even more effective?  Or maybe it would "draw the Wacom's magnetic field into itself" and ruin everything.

Anyway, food for thought.
Logged
Pages: 1 ... 7 8 [9] 10 11
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Valid XHTML 1.0! Valid CSS!