A Couple Suggestions On The Design...


Megatog615

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Joined
Dec 25, 2006
Messages
163
First of all, I'd like to say I love the concept design(you don't hear that enough, I know). Making it a clamshell mini-laptop is the best way to go in my very humble opinion :). I have a few design suggestions, however.

Hardware suggestions:
1. Move the DC-in to the back of the unit. I say this because while using the GP2X(which has this same problem) as it was plugged in, it would give my right hand cramps and I would constantly re-adjust the cable for several reasons, one being comfort on my hand and another being that I would worry about knocking it out on accident. If it were on top of the GP2X instead of the bottom, it would be 90% out of the way(the other 10% outlined in my next suggestion). You could probably do this by moving the SD card slots closer to the USB host port to make room for the DC-in jack.
2. Design the power cable to be straight, not angled. Playing the DS while plugged in to power, the cable never gets in the way because it's straight up and down. The cable plug should also be rectangular, or fit in only one way to prevent it from falling out(using a locking mechanism, like the DS). On a side note, is there a patent that prevents you from using this method?
3. Allow the unit to switch from DC power to battery power on the fly.
4. Please don't use a proprietary battery. Replacing these batteries(at least for laptops) becomes very difficult(and expensive) as the unit gets older. I would rather use 3 or 4 AA batteries. The unit should also detect if the batteries can be recharged and recharge them through the DC-in.
5. Additionally, move the Mini-USB port to the back of the unit for the same reason as the DC-in.
6. Allow the unit to be charged through USB.
7. Please use a wifi chip capable of WPA2.

Software suggestions:
1. Use Dpkg(Debian package management) by default. Install everything with this.
2. Prefer to turn off the keyboard in games(unless requested otherwise) to prevent the user from striking keys around the action buttons(for games that do not use the keyboard).
3. Try to do a lot of power-saving related stuff in hardware and not software. Things such as turning off the screen and sound when the unit is closed(and simply report these changes to the OS). The GP2X seemed to have a lot done in software(such as volume control) and that made it rather annoying to use. I noticed that was a major issue with you as well since you made it use a potentiometer instead of action buttons to control sound, which is nice. You can ignore this suggestion if this is already taken care of.

Thanks for reading :).
 
QUOTE
4. Please don't use a proprietary battery. Replacing these batteries(at least for laptops) becomes very difficult(and expensive) as the unit gets older. I would rather use 3 or 4 AA batteries. The unit should also detect if the batteries can be recharged and recharge them through the DC-in.



Ahhh! as said many many times before... a Lithium battery pack WILL be used, its the only way to power modern high drain devices, and it will be a standard (read: replaceable) size.

Laptops batteries are so expensive because they must power a laptop!

Edit: Imagine what people would say if mobile phones started using AA batteries ;) And do you think laptop manufacturers use a lithium battery (and not AAs) just so they can make extra money when it needs replacing?
 
I disagree abotu batteries, it just adds load of unnecessary bulk to the device, and can't source enough power to run devices for long amounts of time.

I'm still trying to work out why we need a DC-in jack AND a mini USB jack... if we can charge over usb, why not do all the charging over usb, and not add the extra jack.
 
Are you kidding? 4 AA batteries? 2 added enough bulk on the gp2x. 4 would be diasterous on the pandora :)
 
parag0n said:
I'm still trying to work out why we need a DC-in jack AND a mini USB jack... if we can charge over usb, why not do all the charging over usb, and not add the extra jack.
Are there USB-to-wall converters? You know, considering how this will be a portable that you may take to places where you don't have a computer to charge through?
 
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Alex. said:
parag0n said:
I'm still trying to work out why we need a DC-in jack AND a mini USB jack... if we can charge over usb, why not do all the charging over usb, and not add the extra jack.
Are there USB-to-wall converters? You know, considering how this will be a portable that you may take to places where you don't have a computer to charge through?


Yeah, I've seen them branded for Ipod but they have a wall plug and on the other end is a female usb... I've used it to charge plenty a protable device with no problems...
 
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Motorola Razr charges through mini-USB, although it will only charge with the official Motorola wall charger or on a computer running Windows XP.

I think charging through USB is a good idea (as long as there isn't restrictions like Motorola.) It's so nice to finish syncing my iPod from my computer and having it completely charged.
 
Megatog615 said:
5. Additionally, move the Mini-USB port to the back of the unit for the same reason as the DC-in.

2. Prefer to turn off the keyboard in games(unless requested otherwise) to prevent the user from striking keys around the action buttons(for games that do not use the keyboard).

3. Try to do a lot of power-saving related stuff in hardware and not software. Things such as turning off the screen and sound when the unit is closed(and simply report these changes to the OS). The GP2X seemed to have a lot done in software(such as volume control) and that made it rather annoying to use. I noticed that was a major issue with you as well since you made it use a potentiometer instead of action buttons to control sound, which is nice. You can ignore this suggestion if this is already taken care of.
For # 5, I don't remember where, but mweston or ed said that the miniusb would be on the back.
For # 2, I've said it once and I'll say it again. It doesn't matter whether you push buttons on the keyboard if the buttons dont do anything in the emulator. and if they do, reassign them.
For # 3, just so you know, a main focus of this device is to conserve as much power as possible. The TI chip that was chosen was chosen in part because it is awesome at power saving. I think power won't be an issue.
 
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i have to second the mini-usb plug replacing DC in jack. because you can just take the money that it would cost to ship these with DC adapters and just ship them with the usb wall plugs. it should save space on the chasis and maybe a little money not having to furnish the hardware for DC input.
 
Megatog615 said:
Hardware suggestions:
1. Move the DC-in to the back of the unit. I say this because while using the GP2X(which has this same problem) as it was plugged in, it would give my right hand cramps and I would constantly re-adjust the cable for several reasons, one being comfort on my hand and another being that I would worry about knocking it out on accident. If it were on top of the GP2X instead of the bottom, it would be 90% out of the way(the other 10% outlined in my next suggestion). You could probably do this by moving the SD card slots closer to the USB host port to make room for the DC-in jack.
2. Design the power cable to be straight, not angled. Playing the DS while plugged in to power, the cable never gets in the way because it's straight up and down. The cable plug should also be rectangular, or fit in only one way to prevent it from falling out(using a locking mechanism, like the DS). On a side note, is there a patent that prevents you from using this method?
3. Allow the unit to switch from DC power to battery power on the fly.
4. Please don't use a proprietary battery. Replacing these batteries(at least for laptops) becomes very difficult(and expensive) as the unit gets older. I would rather use 3 or 4 AA batteries. The unit should also detect if the batteries can be recharged and recharge them through the DC-in.
5. Additionally, move the Mini-USB port to the back of the unit for the same reason as the DC-in.
6. Allow the unit to be charged through USB.
7. Please use a wifi chip capable of WPA2.

Software suggestions:
1. Use Dpkg(Debian package management) by default. Install everything with this.
2. Prefer to turn off the keyboard in games(unless requested otherwise) to prevent the user from striking keys around the action buttons(for games that do not use the keyboard).
3. Try to do a lot of power-saving related stuff in hardware and not software. Things such as turning off the screen and sound when the unit is closed(and simply report these changes to the OS). The GP2X seemed to have a lot done in software(such as volume control) and that made it rather annoying to use. I noticed that was a major issue with you as well since you made it use a potentiometer instead of action buttons to control sound, which is nice. You can ignore this suggestion if this is already taken care of.

Thanks for reading :).
Hi, thanks for the compliment. I will quote your suggestions so it is easy to reference these answers:

Hardware
1 - done
2 - I agree, but haven't seen any 'official' connectors yet
3 - this should work fine but still testing
4 - sorry, Li Ion battery is necessary here, but maybe some sort of accessory pack for AA's can be made to stick in the battery slot down the road? Pandora won't sit flat on a table anymore as AA's are thicker
5 - done
6 - done
7 - done

Software
1 - sorry, not my area, cannot comment
2 - all buttons can be used however the coder wants. Key presses can be ignored at any time, so in a way sure, it can be turned off :)
3 - Power saving is implemented in hardware but at some point it requires software to actually switch things on and off. BTW, wifi is turned on and off through software control (such as alternate functions on the keypad). Cluttering the unit up with switches seemed unnecessary. I doubt that switch on the PSP actually cuts the power to the chip anyway, it probably triggers an interrupt in the OS that just does it in the background but I will happily be proven wrong if any one really knows.


Also, the DC jack stays as I am sure some people will complain if it is not there. USB charging is slow and for those who don't like the Lithium battery for the reason that the system loses its portability when the battery dies, they will want fast charging. I have one of those Archos 605's and it charges via USB. It takes forever! You can buy a docking station that has a DC adapter and then it charges in a reasonable time but I don't have one so it takes all day!

To make sure the system doesn't cost more, maybe the DC adapter should stay as an add on and just provide a USB cable? Those who will never use it, don't get stuck paying for it.
 
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Will the Li-Ion battery be a proprietary model or will it accept generic Li-Ion batteries(like most cell phone batteries)?

Also, would it be possible to charge through both USB and DC-in at the same time for faster charging?
 
Megatog615 said:
Will the Li-Ion battery be a proprietary model or will it accept generic Li-Ion batteries(like most cell phone batteries)?
It is much bigger than any phone battery so it can be considered proprietary, but there is nothing particularly unique about it and it will be easy to replace. It's like any other device these days though. The battery is designed for the system. We can have extra batteries available for those who want extras for now or for the future, but thinking ahead 10 years and hoping that all the batteries we have today will work then is just a guess. We are definitely more considerate than some companies. People snatch up those iPods, but in a couple years they will have no option to swap a new one in and even more complications when Apple discontinues the model!

QUOTE

Also, would it be possible to charge through both USB and DC-in at the same time for faster charging?


Nope, DC-in takes priority. It's only safe to charge a battery up to a certain rate anyway so as long as the DC adapter can provide it, this would be unnecessary.
 
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Is the charging behavior switched automatically? I know these things never tend to happen in every day usage, but I'm worried someone might fry their unit if something happens.
For example, if you plug both in, the DC-in charges the unit. What if you remove the DC power cable? Does it automatically switch to USB power(or battery power, slowly drained instead because of USB boosting the life)? What happens when you plug the USB in first, then DC-in?
 
geo12 said:
Motorola Razr charges through mini-USB, although it will only charge with the official Motorola wall charger or on a computer running Windows XP.

I think charging through USB is a good idea (as long as there isn't restrictions like Motorola.) It's so nice to finish syncing my iPod from my computer and having it completely charged.
The reason is that it can detect whether its talking to a PC or a charger, and thus draw the appropriate amount of current (you can bet the charger provides much more than 500mA).

If you want to use a non-Motorola charger, then you'll most likely find that they are using the 5th pin of the usb connector for detection of the charger (yes, mini-usb connectors have 5 connectors inside even though usb cables only have 4 wires). It's probably just grounded. This is for safety, so ensure your adaptor is capable of the original adaptors current before doing it!

MWeston said:
To make sure the system doesn't cost more, maybe the DC adapter should stay as an add on and just provide a USB cable? Those who will never use it, don't get stuck paying for it.
The only problem with that is we'll get loads of people trying to use any adaptor that just happens to fit in the hole and then wondering why there Pandora doesn't work any more and returning it saying its faulty. Then you'll have a load more people creating 200 threads a day asking if the 100mA adaptor they found in the basement is suitable. It may be cheaper in the long run to just bundle a suitable adaptor with it, should it be cheap enough.
 
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MWeston said:
I doubt that switch on the PSP actually cuts the power to the chip anyway, it probably triggers an interrupt in the OS that just does it in the background but I will happily be proven wrong if any one really knows.

On the Sony VAIO UMPC, turning off the 'Wireless' hardware switch makes Windows think the wi-fi device has been removed. Turning the switch back on, Windows detects new hardware and installs the "new" device. This makes me think at least in the case of the Vaio UMPC, it could be a physical power switch for the wi-fi device. Not having a PSP, I'm not sure if it is the same or not.
 
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MWeston said:
To make sure the system doesn't cost more, maybe the DC adapter should stay as an add on and just provide a USB cable? Those who will never use it, don't get stuck paying for it.

Sounds fair, provided three conditions are met.

One, the official AC adapter should be of the switching variety (like most these days), not just an inefficient transformer / rectifier.

Two, the plug be of the standard round variety, and the voltage be a common one (not 7.25v or something odd) so that "generic" adapters can also be used.

Three, the price should be reasonable.

I strongly suspect you had planned to meet these conditions anyway, but I figured I'd throw them out there just in case :D
 
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MWeston said:
It is much bigger than any phone battery so it can be considered proprietary, but there is nothing particularly unique about it and it will be easy to replace. It's like any other device these days though. The battery is designed for the system. We can have extra batteries available for those who want extras for now or for the future, but thinking ahead 10 years and hoping that all the batteries we have today will work then is just a guess. We are definitely more considerate than some companies. People snatch up those iPods, but in a couple years they will have no option to swap a new one in and even more complications when Apple discontinues the model!
That is one area that is really a downer with custom batteries. When they are not made anymore you have to throw the unit in the garbage because you can't get the special batteries anymore. All Li-ion batteries have limited charge cycles and they have a limited shelf life. Buying spares will do you no good as if you store them and then go to use them when the battery in the unit dies the spares will be degraded and useless too. Won't there be the same complications if we go to swap in a new one in the Pandora but Craig no longer makes this model? Where are we going to get replacements then? You don't need to worry about that so much with big companies like Apple or Sony, but it is an issue with small companies.

I hate propriatary batteries, I think they are Satan reincarnate. They can be expensive, hard to get, and force you to rely on and buy them from one source. If that one source dries up, take your $250-$300 investment and all of the software you got for it and flush it. That just doesn't seem very user friendly. There should be another option available.
 
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geo12 said:
Motorola Razr charges through mini-USB, although it will only charge with the official Motorola wall charger or on a computer running Windows XP.

I think charging through USB is a good idea (as long as there isn't restrictions like Motorola.) It's so nice to finish syncing my iPod from my computer and having it completely charged.
I've got a Moto RAZR v3 and I charge it through mini-usb using my Linux box. Its a standard USB device and so I've never had any difficulties charging or transferring files to/from it. Maybe it was different on earlier models but being a Linux user and supporter of open standards I never buy any device that requires proprietary drivers to work. In fact I returned a Brother printer to Staples and spent my money on a second-hand Epson CX5200 for exactly these reasons as the Brother printer drivers are only part open source- the cups wrapper is FOSS but the lpr driver (important bit) was closed and so I wouldn't be able to use it on my Zaurus, Pandora unless it was connected to a PC on a network.
 
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Well, even with proprietary batteries, if you do buy one for use when the current one gets too worn out, it's not going to be too awful, provided the machin can make use of almost all of the charge present.

Specifically, if the Wikipedia article on 4% degrade when stored at room temperature and at 40% capacity in a year is accurate, then even 10 years later, an unused battery provides ~66% of the original capacity. If the original play time is ~10 hours (fingers crossed), then that's still a 6-hour play time which isn't bad.

And if you keep it cool, then it's even better :).

20 years later, though, and Pandora will be a little dead, unfortunately :(. 44% is starting to get a bit low.
 
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