Talk:Gta02-core

From Openmoko

(Difference between revisions)
Jump to: navigation, search
(audio improvements are very desirable but "best-effort")
(No change to case design)
 
Line 12: Line 12:
  
 
[[Werner]]: people interesting in experimenting with case (re)design are entirely welcome to. It's just out of scope for gta02-core. I've [http://lists.openmoko.org/pipermail/gta03/2009-May/000207.html posted some ideas] to the gta03 list.
 
[[Werner]]: people interesting in experimenting with case (re)design are entirely welcome to. It's just out of scope for gta02-core. I've [http://lists.openmoko.org/pipermail/gta03/2009-May/000207.html posted some ideas] to the gta03 list.
 +
 +
I know this is outside of scope, but one of the major case ID "bugs" I found is that the USB and headset cables both come out right where you hold the device - so if it's plugged in to USB a right-hander can't hold it, and if it's pluged into a headset a left hander can't hold it. It would be good to have all cables at the top or bottom of the device. Secondly, the screen is really deep set, making it hard to get into the corners when you don't have a stylus, but thirdly, there's no place for a stylus. It'd also be really nice to have a couple of more buttons - perhaps including an up-down set that could be used for scrolling/volume control. Most of these are pretty minor though, really, I'm really impressed with the device as a whole. --[[User:Naught101|Naught101]] 22:27, 11 January 2010 (UTC)
 +
 
=What about USB 2.0?=
 
=What about USB 2.0?=
 
[[Pini]]: The title says it all :) It would be for sure a great improvement. Thanks.
 
[[Pini]]: The title says it all :) It would be for sure a great improvement. Thanks.

Latest revision as of 23:27, 11 January 2010

Contents

[edit] Only one accelerometer

RuiSeabra: Do not remove one of the accelerators, having two vectors is useful for many applications.

daveb: I've heard lots of contradictory information about this, but I'm certainly not an accelerometer expert. My understanding is that as accelerometers detect lateral movement, but not rotation through their axis, the second accelerometer is intended to detect movement in one accelerometer when the device is rotated through the axis of the other. However, if the devices are too close together, it's difficult to get a useful reading? At the moment, are there freerunner applications which require two accelerometers? (does omnewrotate use both?) My understanding from the lists is that connecting both interrupts to one accelerometer will offer more benefits than sticking with two accelerometers.

Werner: when I asked whether anyone actually had an existing use case for two accelerometers, I got no replies. So it seems that having just one is good enough for real life.

[edit] No change to case design

daveb: For gta02-core, we're planning to build something that will fit inside the GTA02 case. A new Id involves lots of complexity and cost - designing the case, manufacturing molds, properly understanding the EMI properties of the new case, and designing the aerials that need to fit in it. [Though as Werner clarified, this wasn't intended to discourage folk that want to investigate a new case. New case designs would be fantastic, but aren't part of what we intend to deliver through gta02-core. We will be working to a board which fits the existing gta02 case - or any alternative case which works for gta02 boards.]

Werner: people interesting in experimenting with case (re)design are entirely welcome to. It's just out of scope for gta02-core. I've posted some ideas to the gta03 list.

I know this is outside of scope, but one of the major case ID "bugs" I found is that the USB and headset cables both come out right where you hold the device - so if it's plugged in to USB a right-hander can't hold it, and if it's pluged into a headset a left hander can't hold it. It would be good to have all cables at the top or bottom of the device. Secondly, the screen is really deep set, making it hard to get into the corners when you don't have a stylus, but thirdly, there's no place for a stylus. It'd also be really nice to have a couple of more buttons - perhaps including an up-down set that could be used for scrolling/volume control. Most of these are pretty minor though, really, I'm really impressed with the device as a whole. --Naught101 22:27, 11 January 2010 (UTC)

[edit] What about USB 2.0?

Pini: The title says it all :) It would be for sure a great improvement. Thanks.

Werner: I wish :-) Unfortunately, the S3C2442 can only do USB 1.1.

[edit] Proper buzz fix

Mazikeen: Will there be a mod to prevent the ingress of GSM signal via the headset mic input, or indeed any other way t might find its way inside the can?

Werner: proper application of beads is indeed very high on my list. I'm also rather suspicious about TX/RX passing unbeaded between CPU and GPS. This will require the addition of components that don't exist on the original BOM, so we'll have to be careful what this does to the general budget. But I think it won't be a problem to get this right.

[edit] Bass fix

Mazikeen: Can we finally sort the low dc blocking cap value and parallel resistor value Joerg identified before release?

Werner: My plan is to pick up as many fixes as possible from what we know is broken in A7, from what was projected for A8, and also from the GTA03-6410 circuit. This is limited by the riskiness of changes and their impact on the BOM. I also hope Joerg can continue to give us guidance on getting the audio right. Making the "perfect" GTA02 isn't the main goal of this project, but if we can solve problems without jeopardizing the project, we should.

Personal tools

Only one accelerometer

RuiSeabra: Do not remove one of the accelerators, having two vectors is useful for many applications.

daveb: I've heard lots of contradictory information about this, but I'm certainly not an accelerometer expert. My understanding is that as accelerometers detect lateral movement, but not rotation through their axis, the second accelerometer is intended to detect movement in one accelerometer when the device is rotated through the axis of the other. However, if the devices are too close together, it's difficult to get a useful reading? At the moment, are there freerunner applications which require two accelerometers? (does omnewrotate use both?) My understanding from the lists is that connecting both interrupts to one accelerometer will offer more benefits than sticking with two accelerometers.

Werner: when I asked whether anyone actually had an existing use case for two accelerometers, I got no replies. So it seems that having just one is good enough for real life.

No change to case design

daveb: For gta02-core, we're planning to build something that will fit inside the GTA02 case. A new Id involves lots of complexity and cost - designing the case, manufacturing molds, properly understanding the EMI properties of the new case, and designing the aerials that need to fit in it. [Though as Werner clarified, this wasn't intended to discourage folk that want to investigate a new case. New case designs would be fantastic, but aren't part of what we intend to deliver through gta02-core. We will be working to a board which fits the existing gta02 case - or any alternative case which works for gta02 boards.]

Werner: people interesting in experimenting with case (re)design are entirely welcome to. It's just out of scope for gta02-core. I've posted some ideas to the gta03 list.

What about USB 2.0?

Pini: The title says it all :) It would be for sure a great improvement. Thanks.

Werner: I wish :-) Unfortunately, the S3C2442 can only do USB 1.1.

Proper buzz fix

Mazikeen: Will there be a mod to prevent the ingress of GSM signal via the headset mic input, or indeed any other way t might find its way inside the can?

Werner: proper application of beads is indeed very high on my list. I'm also rather suspicious about TX/RX passing unbeaded between CPU and GPS. This will require the addition of components that don't exist on the original BOM, so we'll have to be careful what this does to the general budget. But I think it won't be a problem to get this right.

Bass fix

Mazikeen: Can we finally sort the low dc blocking cap value and parallel resistor value Joerg identified before release?

Werner: My plan is to pick up as many fixes as possible from what we know is broken in A7, from what was projected for A8, and also from the GTA03-6410 circuit. This is limited by the riskiness of changes and their impact on the BOM. I also hope Joerg can continue to give us guidance on getting the audio right. Making the "perfect" GTA02 isn't the main goal of this project, but if we can solve problems without jeopardizing the project, we should.