AlanS
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Re: Challenge to engineer a Raspberry Pi dock connector

Sat Feb 18, 2012 9:42 pm

I have seen a number of people posting about the need for a dock for the R?.

The following article, offered for comment and criticism, is aimed primarily at educators, though it applies to all users, arguing for the use of a posturally-safe workstation with any sort of portable computer.  With a heavy laptop, the engineering required to create a reliable dock connector is expensive.  But the R? is so close in technology and size to a mobile phone that engineering a dock connector with the ‘dockability’ of an iPhone should be far less demanding.

Please could someone with the necessary skills try to engineer this with a beta board?  If it works with leads brought from all the board's existing sockets, then one could only hope that a future version of the board with the dock connector riveted to the board should be fairly easy to produce.  The sooner this can happen, the sooner docks can be developed.  If the safety case isn't immediately obvious to you and you're interested, please read on.

When is computing potentially hazardous to learners' health?

There are many, oft-rehearsed arguments for providing learners with their own computers. Self-contained, portable computers such as laptops, netbooks and tablets possess the additional advantage of enabling learners to use the same software and data resources at home as well as at school. Furthermore, such self-contained portable computers are often highly attractive to educators, as, at the lower end of their price range, they are more affordable than a desktop or nettop computer workstation. They also take up less scarce space in classrooms and can be relatively easily moved between classrooms. Even quite low-powered devices can perform as remote desktop clients when connected to a network server that hosts applications and files.

For computers to be effective tools for learning, many factors need to be considered, such as affordability, standardisation, physical and data security, maintenance, teachers' access to relevant, timely training and expertise, and learners' e-safety. Less frequently considered is the question of how portable computers can be used in ways that avoid hazards to health such as neck pain, upper limb disorders (ULDs), including repetitive strain injury (RSI), and eyestrain.

Why does postural safety matter?

Employees who perform substantial work with computers in Great Britain are covered by the Health and Safety (Display Screen Equipment) Regulations 1992 (http://www.hse.gov.uk/msd/dse/) published by the Health and Safety Executive (HSE) and designed to protect the health of people who work with all sorts of display screen equipment, including computers. Since learners in schools are not employees, they are not legally protected by these regulations.

However, if we are embracing the use of computers as tools for learning for a substantial proportion of the school day, we owe it to learners to enable them to use computers as safely at school as in the workplace, protecting them from distortions of posture (especially kyphosis, an excessive rounding of the upper spine) and excessive wear-and-tear of the intervertebral discs in the neck that are liable to cause them health problems in later life, informing them about safe practice in the workplace and making them aware of the risks they run if they choose to use computers less safely at home.

Principles of safe computer use

These may be summarised as:



Seating should provide adequate support for the user's back to remain relatively straight.



Seating height should be adjustable relative to the desk, so that the user's elbows are just above keyboard-level and their wrists are straight.



Screen height should be adjustable so that the centre of the screen is just below eye-level – anything lower than this encourages craning of the neck and hunching of the back.



Screen angle should be adjustable to optimise screen colour and contrast.



Natural and artificial light should be directed to minimise unwanted reflections from the desk and screen.



The potential hazards

Portable computers are suitable for occasional use, but are not ergonomically designed for sustained use. A standard laptop or netbook used by itself cannot conform with the principles listed above concerning keyboard and screen; the keyboard and screen are simply too close together for typing without bent wrists while viewing the screen with a healthy head and neck posture. See for example, the head and neck posture in http://www.ncl.ac.uk/gps/asset.....p_user.jpg and http://newsroom.kaspersky.eu/f.....t_male.jpg.

Similarly, using the virtual keyboard on the touchscreen of a tablet computer on a lap-stand or non-elevated table-stand will require excessive neck and risk flexion, as discussed in http://iospress.metapress.com/.....lltext.pdf. Conformance with the relevant principles can only be achieved with a tablet computer or smartphone, if the device is used at eye level. Even the level shown in http://news.bbcimg.co.uk/media.....let624.jpg is slightly too low. Clearly, sustaining such an arm posture for more than a few minutes would be very tiring and unsatisfactory for sustained work.

However good a room's lighting design is, all types of portable computer can easily be inadvertently placed in positions that produce unwanted reflections. While it is debatable whether a bean bag can ever support a healthy posture, it is highly unlikely that it can comply with the regulations when used as seating for a learner using a portable computer (http://static.guim.co.uk/sys-i.....-u-007.jpg).

Mitigating the risks

The HSE's booklet The law on VDUs: An easy guide (http://www.hse.gov.uk/pubns/bo...../hsg90.htm) states: “Whenever possible, users should be encouraged to use their portable at a docking station. Or, they can use the portable with a plug-in full-sized keyboard and mouse, enabling the height and position of the portable’s screen to be adjusted by placing it on raiser blocks.”

So a laptop, netbook or tablet can conform to the principles listed above concerning keyboard and screen, if the whole computer or detachable laptop screen is elevated on a stand that is adjustable to suit each hot-desking learner's height and used with external keyboard and pointing device. Alternatively, the portable computer can be attached to a separate, adjustable screen. The most convenient and least problematic way of connecting a laptop to a screen, keyboard and pointing device is to place it on a docking station to which these devices are attached. Unfortunately, laptops equipped with detachable screens or docking stations tend to be very expensive, partly because of the additional high-reliability connectors required and partly because of the relatively low volume of production.

So, notwithstanding the other potential advantages of using portable computers in the classroom, facilities for safe input and output during their sustained use require as much space and possibly even greater monetary expenditure than those required for a desktop or nettop computer.

An ultra-low-cost dockable, portable computer?

The Raspberry Pi is a credit-card sized, Linux computer based on a mobile phone processor. Harking back to the era of Sinclair ZX computers, it is not supplied with a display screen and relies on an external HDMI-compatible screen and loudspeakers, such as a domestic television, for output. The Raspberry Pi is available for as little as $35 (with Ethernet) because it is also supplied without any input devices.

So, the Raspberry Pi represents an extremely low-cost, “micro”, portable computer. Although some will no doubt use it as the heart of an ultra-low-cost netbook or tablet computer, educators probably need to concentrate on making it dockable with posturally-safe workstations.

The challenge exists for the Raspberry Pi project to engineer an open standard for a durable and easy-to-use dock connector, perhaps similar to that used on Apple media player, smartphone, and tablet products, for docking the computer with an adaptor that connects the computer to power, HDMI, USB hub for peripherals, and Ethernet at a workstation.

Lynbarn
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Re: Challenge to engineer a Raspberry Pi dock connector

Sat Feb 18, 2012 10:44 pm

Firstly, Welcome AlanS,

Some interesting points you've made here, but I'm not sure how relevent they are to the 'Pi.

Whereas the lighting, keyboard angle, screen position, glare, etc. are important issues, they do not directly impact on the 'Pi because, as a "black box" (well, the education versions will be in a case, although I'm not sure of the colour) which has no moving parts, indicators (apart from 5 status LEDs) or controls and merely has peripherals plugged into it, rather than a "Self-contained, portable computer", the provision of a docking station, whilst of some physical benefit (only having to plug one socket in), seems to offer little in terms of cost-effectiveness, and none in terms of postural safety. The issues related to the DSE regulations and equivalents elsewhere are valid, and need to be taken into consideration, but relate to the peripherals, rather than the 'Pi itself. Also, the 'Pi is likely to be used in a wide range of situations, environments and for an even wider range of applications, all of which will have different external requirements.

There are also technical and cost considerations in the design and implementation of such a docking port on the 'Pi - space is at a premium, and the cost, as a percentage of the overall cost of the 'Pi, will be high.

Certainly, as far as the Foundation is concerned (I'm not talking for them, by the way - this is just my own opinion), I think they will have enough to keep them busy for the next several months - even years - with the current design, without totally redesigning the board and adding extra components to provide the docking port.

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reiuyi
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Re: Challenge to engineer a Raspberry Pi dock connector

Sun Feb 19, 2012 12:36 am

The more I read your post, the higher my mind thinks the price for a workstation will be

Telling kids they shouldn't sit hunchbacked in front of their computer is all right, though as soon as the words "health & safety" come up, it's like the supplier automatically tenfolds the price while not changing the hardware at all. The university I attend has those completely ergonomical work spaces and it cost them an absolute fortune. By "fortune" I'm talking thousands of euros for a computer plus a desk and a chair. The health of pupils is important, yet wasting community money in such a way isn't really nice either.

Though as the person above me said; pi foundation doesn't have any of those points on their agenda. They just want to produce a cheap computer. It''s not their task to make sure kids sit straight

gritz
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Re: Challenge to engineer a Raspberry Pi dock connector

Sun Feb 19, 2012 2:58 am

Interesting post - and remember it's not a computer (in the sense of a thinger that can do useful stuff) until it's got some I/O attached to it, even if it's only a button and a beeper. Until then it's just a pcb.

I can imagine that educational establishments would be most concerned about the dreaded Health and Safety, as well as standardisation and robustness. (and making it aesthetically appealing to the kids it's going to inspire). Still, as the first run is destined in the main for developers / enthusiastic amateurs / hackers etc I'm sure that V2.0 will address these issues. No point in making something super cheap at the expense of a short lifetime.

khulat
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Re: Challenge to engineer a Raspberry Pi dock connector

Sun Feb 19, 2012 12:43 pm

I don't think it is intended to be used as a portable device by schools. It's intended as a cheaper alternative to classical computers. In that regard a expensive docking station would be the false direction to take.

And while ergonomics are important i really don't see the connection between ergonomics and a docking station, especially if you look at the pi which is not a Notebook, but a PC.

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grumpyoldgit
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Re: Challenge to engineer a Raspberry Pi dock connector

Sun Feb 19, 2012 12:58 pm

AlanS

I don't see the Pi as being portable at all unless someone is involved in a project to make a Pi laptop. Many of the projects don't even plan for the Pi to have a keyboard or screen. This seems like a solution in search of a problem. Do you work for a company that manufactures docking stations by any chance.?

timgiles
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Re: Challenge to engineer a Raspberry Pi dock connector

Sun Feb 19, 2012 1:24 pm

Isnt it strange - I now live in Sweden where H&S is almost non existent. People live longer, better, more forefilled lives. They seem to take the knocks that life throws as that, a challenge that needs overcoming. They do not wrap in cotton wool.

Then I think back to BG who I used to work for. Oh yes, millions spent on a fancy new IT accident recording system, millions spent on giving the safest possible tools, but in the end, all it needs is for an electrical engineer to reach in to a live appliance and it means for nought.

Everyone I worked with, H&S related, seemed to know that they were protecting me and everyone else in the world. Its a shame that no one informed them that 90% of the time, they were producing procedures and bringing in new working practices that comprised something we used to call common sense. We didnt need to pay Mr Health or Miss Safety 40k a year + to tell us that we were working with our monitor 3 degrees too tilted. I knew thanks, and thats how I liked it.

Oh how I dont miss this aspect of living abroad from the white cliffs, spitfires and real ale.

gritz
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Re: Challenge to engineer a Raspberry Pi dock connector

Sun Feb 19, 2012 4:29 pm

Of course the Pi will be in some senses a portable device - unless (for instance) an educational establishment dedicates a room to rows of 'em permanently plumbed into monitors and keyboards - like I said it's not a computer until it has some I/O.

I can't really see a bare pcb lasting five minutes "in the wild". That's why (I guess) the V1 is destined for hackers and modders. But I mentioned that "up there" ^^^.

khulat
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Re: Challenge to engineer a Raspberry Pi dock connector

Sun Feb 19, 2012 4:36 pm

Well since they do need the room for the rows of monitors and keyboards anyway, i don't see much reason to have the Pi be mobile while the monitors are effectively immobile.

The educational version will of course have a case, so the bare pcb won't be a problem then as you said.

gritz
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Re: Challenge to engineer a Raspberry Pi dock connector

Sun Feb 19, 2012 8:09 pm

khulat said:


Well since they do need the room for the rows of monitors and keyboards anyway, i don"t see much reason to have the Pi be mobile while the monitors are effectively immobile.

The educational version will of course have a case, so the bare pcb won't be a problem then as you said.


I was thinking that if the Pi is destined for educational use in (say) the emerging world then dedicating (or building) a classrooom to house rows of monitors, keyboards, wires and whatnot is a bit of an ask. After all this is about accessing computer education on a budget. Therefore I could foresee a lot of pluggig and unplugging…

khulat
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Re: Challenge to engineer a Raspberry Pi dock connector

Sun Feb 19, 2012 8:50 pm

Well the budget surely will not be better off if there is the added cost of a docking station.

Also I admit that I am ignorant of school systems in most countries, but I really can't see how anyone would use the Pi to teach anything without having a room with at least one Monitor/Keyboard etc.

Maybe you can describe a scenario in which the Pi has to move regularly that I just haven't thought of yet.

I still maintain my stance that a dock would have little to do with ergonomics and health related issues, unless you want to make the children plug the thing in and out all day long.

Bad Wolf
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Re: Challenge to engineer a Raspberry Pi dock connector

Mon Feb 20, 2012 8:46 pm

AlanS said:


Please could someone with the necessary skills try to engineer this with a beta board?  If it works with leads brought from all the board's existing sockets, then one could only hope that a future version of the board with the dock connector riveted to the board should be fairly easy to produce.  The sooner this can happen, the sooner docks can be developed.  ...



Having thought long and hard as to how to achieve this

(OK, not that long or hard).

I think I have come up with the ultimate budget dock station

To a person with a hammer, everything looks like a nail.

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abishur
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Re: Challenge to engineer a Raspberry Pi dock connector

Mon Feb 20, 2012 8:50 pm

Bad Wolf said:


AlanS said:


Please could someone with the necessary skills try to engineer this with a beta board?  If it works with leads brought from all the board's existing sockets, then one could only hope that a future version of the board with the dock connector riveted to the board should be fairly easy to produce.  The sooner this can happen, the sooner docks can be developed.  ...



Having thought long and hard as to how to achieve this

(OK, not that long or hard).

I think I have come up with the ultimate budget dock station





HA!  Not only am I a big fan of your name (that was one of my favorite season finales), but I like your solution.  I just imagine the r-pi taped or velcroed to the back of the desk just out of sight!
Dear forum: Play nice ;-)

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Vindicator
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Re: Challenge to engineer a Raspberry Pi dock connector

Mon Feb 20, 2012 9:18 pm

I am more of a fan of duct tape but I like the approach LOL, Edges of my desk are rounded so this might not work for me, but good old duct tape can defeat round edges.
If you are more worried about ,spelling, punctuation or grammar you have probably already missed the point so please just move on.

spurious
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Re: Challenge to engineer a Raspberry Pi dock connector

Mon Feb 20, 2012 9:30 pm

love the "Bad Wolf" dock.. but wouldn't it be cheap enough to leave the little board in place and buy another for a different location?

Probably about £2 worth of bulldog clips there.. add £20 and you have a 2nd R-Pi.

Stick some WD40 on the SD card release and you have slick one press release of the boot media.

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grumpyoldgit
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Re: Challenge to engineer a Raspberry Pi dock connector

Mon Feb 20, 2012 11:30 pm

My cables come up through a round hole in the worksurface. After many years of having to scrabble on my hands and knees to retrieve cables, I came up with this foolproof solution.


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