Audio hardware

From OLPC
Jump to navigation Jump to search

Network/Hardware Ideas

Microphone

A built in Microphone would be usefull if dirt and echo/feedback could be controlled. If you have a microphone and speakers included with these laptops then then if you include a small peice of software they can be used as telephones or walkitalkies -- like an instant message local channel that is as easy to use as a CB radio. If the hardware looked like a radio, the oporator could use it before they learend how to use the computer.

The provenance laptop

An issue about the provenance of the particular copy of the (yet-to-be) published program obtained for running by a child on a laptop has been written about in the http://wiki.laptop.org/index.php/Application_Program:_Test_of_ability_with_arithmetic#Verifying_the_program section of the http://wiki.laptop.org/index.php/Application_Program:_Test_of_ability_with_arithmetic page.

A possible solution has been suggested. This is termed a provenance laptop therein. It is different from the server version which is suggested above.

In view of the fact that the provenance issue is likely to be important for many programs, not just for the application program in relation to which the issue was raised, the idea of the provenance laptop is copied to this Hardware Ideas page.

Would it be possible for there to be a special, variant, version of the laptop, say moulded in a colour different from the laptops issued to the children, which is read-only of files, with files being obtainable only over the internet and then only from one particular webspace? This special, variant, version is herein termed a "provenance laptop". The system software for such a provenance laptop could be in read-only memory. Thus, if the idea is feasible, a child could obtain files from a provenance laptop with confidence. The provenance laptop might, from time to time, need to be transported several miles to a place where files could be obtained from the internet. However, the availability of a provenance laptop facility in a rural school where there is no direct connection to the internet could be a good second best to having a direct internet connection. The provenance laptop could be used to select which files are obtained from the one particular webspace. The one particular webspace could either be a special webspace run by the government of the country where the laptop is deployed or a special webspace of the OLPC project run by the OLPC management under secure conditions, depending upon the policy choice of the government of the particular country.

Broadcast and Satellite

See Hardware Ideas - Broadcasting

Motorcycle Net

There are already people using motorcycle delivery services to carry email from village to village. I believe it is in Vietnam but it may have been Thailand. This type of networking is likely to grow once there are large numbers of wireless capable laptops in place. They either exchange info wirelessly with the motorcycle, or, more likely, a teacher runs a village base station that can collect messages all week, then do a quick upload and download while the motorcycle driver is dealing with the paper mail. Bulk data transfers would be on CD or DVD since USB drives are readily available. The villagers will quickly learn how a single USB-CD drive can multiply the usefulness of those laptops 100-fold.

It may be in Vietnam as well but this article shows that it is definitely in place in Cambodia: http://www.parish-without-borders.net/cditt/cambodia/dailylife/2004/rural-internet.htm

Support for this and mention of telesoftware and of MHP

Yes, good idea.

You might like to consider using telesoftware, that is the unidirectional cyclic broadcasting of software and its selective use, to broadcast software packages for the laptop as well.

The following webspace about the DVB-MHP (Digital Video Broadcasting - Multimedia Home Platform) interactive televison system might be of interest.

http://www.mhp.org

The MHP system broadcasts Java programs to interactive television sets.

The following idea, not implemented as far as I know, might be of interest in relation to digital radio.

http://www.users.globalnet.co.uk/~ngo/tor00000.htm


William Overington

5 March 2006

There is now a page about the possibility of an MHP to laptop interface

There is now a page about the possibility of an MHP to laptop interface.

[[1]]

One way connection to internet helps nothing. This is passive usage like watching tv. Software distribution with USB is easy.

  • Yet in areas of the world where a two-way link is impossible, a one-way system where lots of software and data such as electronic textbooks can be received from direct to school broadcasts from a geosynchronous television broadcasting satellite and stored localy, telesoftware could be very advantageous.

Hardware/Accessory Ideas

Keyboard

Moved -- see Hardware Ideas - The Keyboard

Green Hardware

Some Ideas from WorldChanging: "...We typically discuss organic polymer electronics (OPE) as a feature of the fabrication future, but the clean leapfrog application is important, too. The production of OPE is much cleaner than traditional electronics, and the materials themselves contain few if any heavy metals. Recent OPE developments include a microprocessor able to run at around 100MHz (far slower than today's fastest laptops, but easily fast enough for the kinds of basic information and communication tasks described for the OLPC project), a variety of slower circuit and sub-processor plastics, an organic polymer battery and even a colorful, fast flat-panel display. Even the solar panels often suggested as an add-on for the hundred dollar laptop could be made with organic polymer materials."

Power and Batteries

When you look at military PDAs,they are powered by fuel cells that aren't so available in these countries and are not in the price range being considered. We have to do something with the options available.

Make your own batteries

Is it feasible for the kids to make their own batteries to power the OLPC? This would be a fantastic science project if it is possible. If potato and lemon powered clocks are possible, this should be too.

Batt types and charges

If you are constantly recharging the battery all the time this will greatly decrease the life of the battery.

NiMH batteries do not suffer from "memory effect", in fact NiCd batteries don't normally either. But, both types do suffer from voltage depression; when they are fresh and new they give a voltage of 1.2v per cell so 8 cells will give 9.6v, a useful amount. But if the cell is over charged or just always on trickle charge the cell voltage soon drops to just about one volt per cell; just 8v total, the equlivent of removing an entire cell. The interesting thing is voltage depression does NOT effect the total capacity of the battery. I have NiMH and NiCd that are completely depressed (hmmm) but they still do the job as well as they did when new.

The problem with this is the discharge graph [2]. You will notice that it's mostly flat so some designers take the 1.2v as gospel and design thier electronics to shutdown at 1.1v. If the battery is depressed by 0.2v this line comes in at about 10%..15% of the way into the capacity so you only get 10%..15% of your two and a bit hours of charge ... 20 minutes... 62.252.0.11 15:42, 17 March 2006 (EST)


i heard that nicd and nimh batteries have some fake memory effect: it was said that they were afected by another redox transformation than the normal,when they keep staying pluged on after having fully recharged the batteries: this redox transformation will divide the battery in 2 and have a part with the normal voltage and another part with an inferior voltage usualy that caan be easely detected because there is a voltage jump and so they needed to be full discharged with a resistor in order to get back their capacity but i don't remember the formula for calculating the value of the resistor 213.189.165.28 19:48, 4 April 2006 (EDT)

Microphone data input

The microphone input jack can double as a dataport for some class of devices (when supporting a "DC-coupled" input mode), but a more general-purpose USB analog to digital device would be a great peripheral for the laptop. --Walter

AD/DA & "Parallel" interfaces

Precisely for these types of ideas the computer needs some sort of basic A/D, D/A and suitably protected bi-directional "parallel" type interfaces. These need to be built-in so their use doessn't add wire spaghetti, cables/conversion boxes don't get lost, is "fumble free" and always available. In short, it must be simple, empowering and an idea generating catalyst. L Pfeffer March 20, 2006
  • Or perhaps these miscellaneous fun things should all be available on a USB interface. It would keep it very expandaple, yet low base cost. USB devices keep getting less expensive to develop. --imajeff


Serial Port??

I know it can be done thru USB emulators... but serial ports are simple and easy to use. If someone wants to make some electronic project, or using old hardware (mouse, or serial comunications devices), it could be useful to have one.

it's just an idea, but I started making my first hardware projects with this, and even today is cheaper (at least here in Argentina) and easy to make serial ports working hardware (rather than buying PICs and programming them).

And still many hardware has serial ports (networking devices for example).

Gandolfi

Serial ports are NOT robust, at least nine tiny little pins that it's very easy to bend or break, not a good idea. Perhaps with a more robust connector, though IME the parallel port was more useful for electronics projects. 62.252.0.11 16:02, 17 March 2006 (EST)
The photos from the developer boards show an external RS232 level shifter circuit attached (to some GPIO pins?). Legacy serial/parallel ports are nice for experimenting, there's IMHO no need for this for a laptop which is targeted at 6-12yo childs.
Not to mention the fact that there IS NO OLD HARDWARE in these 3rd world villages. It would be far better to have an external power plug with circuit breaker switch so that people could use the old bananas they have laying around TO MAKE BATTERIES!!! The kids will be motivated to find a way to pedal less so lets help them learn some science.


Additional Architectural Elements

See Hardware Ideas - Additional Architectural Elements


ORP 12

Moved to Hardware Ideas - Fun Things.

Including built-in streaming from e.g. teacher to students

Would the current architecture, including display design/resolution/framerate etc. allow for this in principle?

On the software side, how about some peer-to-peer streaming stuff; one CD or DVD drive/player per school class, and groups of kids watching a (same) movie on several laptops? This is possible with e.g. VLC - but could be built-in, preconfigured/high-lighted and very simple - thingie pops up saying "A neighboring laptop has started streaming video, would you like to watch?" - done.

The hardware exists off the shelve... but will they all work out of the box? Drivers? Can player software be included in the "default" software? If not a full-blown "certification" program, at least at page (on this Wiki!) with "external devices known to work" (or if not, instructions on how to get them to work will probably be needed.

Vorburger

Not a laptop, but an X-Term!

Is anyone willing to consider a more immediately available, dumb-terminal version of the device which would have nothing more than a touchscreen and an ethernet port?

I WANT! A small silent X-Terminal/Media player connected by WiFi/Ethernet to a big box will be a killer app for the Linux based home or office network. Doesn't work with Windows, Microsoft see to that. This is a different spec to the OLPC though, you'd want POE or better yet network over 6-pin firewire (firewire is designed to supply lots of power) you'd probably want a 1024x768 full colour screen and perhaps more memory. This is the $2000 version of the PC. 62.252.0.11 03:35, 12 April 2006 (EDT)

Reinventing the OLPC

Make it for us, too

There is a constant chorus of voices asking for a version of the OLPC to be sold in the Western world at a higher price with the profits being use to fund the distribution of more OLPCs in the target areas.

A price point that is often mentioned is $300.

This could be done by spinning off a separate charitable organization to engage in the manufacture and sale of these devices. Ideally, there would be some physical differences as well so that OLPCs from the target area cannot be economically transformed into sellable ones.

Suggested modifications for commercial model

  • Grey colored case similar to most laptops
  • Different shape to the case to make it slimmer
  • Keyboard capable of being used for any European language that uses a Latin or Cyrillic script
  • Integrated type II compact flash slot inside the case. Intended to provide larger storage capacity for westerners. Sell the unit without the flash so that people can buy their own CF chip or CF drive to install.
  • Easy opening case to get at the innards. Westerners will tinker and service their own devices.
  • Package it with a power brick instead of the cranking pedal


Why omit the cranking pedal? The ability to charge the machine without access to an electrical outlet is one of its unique features that makes the device attractive compared to run-of-the-mill Celeron laptops that are quickly dropping into the $300-$400 range. - Jim Kneuper