techpaul
Posts: 1512
Joined: Sat Jul 14, 2012 6:40 pm
Location: Reading, UK
Contact: Website

Re: Minor improvements for a model C

Sun Aug 12, 2012 10:33 am

As if by magic I see someone has tried to connect a 2.5in USB hard drive to a Pi . See

http://www.raspberrypi.org/phpBB3/viewt ... 38#p148238
Just another techie on the net - For GPIO boards see http:///www.facebook.com/pcservicesreading
or http://www.pcserviceselectronics.co.uk/pi/

toxibunny
Posts: 1382
Joined: Thu Aug 18, 2011 9:21 pm

Re: Minor improvements for a model C

Sun Aug 12, 2012 10:36 am

techpaul wrote:
If you really want to get a better RasPi then ask that the Alpha model go into production with a 512MB memory module in place of the 256MB. The Alpha design was funded by Broadcom. So the board design really does not belong to the foundation. But if someone asked nicely maybe Broadcom would allow it to be made!

Alpha specs included:
6v to 20v operation through a 5.5mm power connector.
full spec (500ma) USB ports
Switching rather than linear regulators. Idle current was like under a watt with 2.25 watt max load (I believe that included a draw from keyboard and mouse)
More GPIO! all 26 pins were connected. Included I2s and I2c, 2 PWM's (if memory serves me)
There were a couple of other pin strips on the board as well
Well if the Alpha also made and the pin strip for GPIO actually a shrouded connectror like standard IDC ribbon cable connectors I would agree, as that is the main non-polarised connector on the board. The only other accessible one being the JTAG.

Personally going anywhere near education long term with pin strips and not polarised connectors is asking for trouble. Yes I deal with education market daily, the other half is a teacher for ICT and Computing subjects, so often making things for her or doing talks or helipng on the kids projects as the 'customer'.

This.
note: I may or may not know what I'm talking about...

User avatar
reiuyi
Posts: 165
Joined: Sun Oct 09, 2011 4:59 pm
Contact: Website

Re: Minor improvements for a model C

Sun Aug 12, 2012 5:33 pm

techpaul wrote:I note you did not quote my bit about 13A (thirteen Amp) sockets wired with 3A (three Amp) cable very teling.

Live in the real world a general computer with USB ports will have users plugging in any USB device that was the point of the standard.

The micro USB connector for power was a silly idea from day one as many micro USB cables are price manufactured down for SPECIFIC very low power devices and users will pick up any USB cable thinking they are all the same and many will put excessive volt drops and current limits.

As to power tracking I bet most of the 5V is actually in inner planes used only for power, so in effect is very wide.

Anyway a track capable of carrying 1A to the USB (two ports) is not as wide as you may think, it is around 0.4 to 0.5 mm wide for outer layers which it probably is at the moment or wider. It would have to be less than 1oz Cu to need wider than 1mm track on outer layers. Yes I lay out PCBs for my designs as well.

FYI last lot of USB 2.5 inch hard drives I used draw from USB power at ratring of 500mA last measured one was 400mA. The 500mA limit works with all self-powered USB 2.5 hard drives that I have used current job for one customer requires TEN of them they all work fine. 2.5 inch drives are laptop drives meant for low power usage and 5V only. Oh I have used them oin many systems of various vintages as well.

So far you are the only person who supports the current scheme I see no one else supporting in ANY thread anywhere. Having the attitude of it is fine is someone who does not understand the amount of things that can go wrong or has experience of real world users in their day to day life with electronic equipment.

I am someone who has for years had to design things to ensure users cannot do something beyond the spec with trying really hard, not doing what they are supposed to do.

I just hope you don't do any electrical wiring.

Allright allright I'll answer your domestic 13a limit. Where I live, people are often surprised they require a domestic three-phase power connection when installing a brand new all-electric kitchen. 3-phase is vastly superior to using mains with electric kitchen stoves, and where I live everyone has access to 3-phase to their home without much hassle. Even in modern homes, you cannot expect some electric things to "just work" when they're plugged in. Washing machines have their own electrical group and some hobbyists prefer a 1:1 isolation to prevent their oscilloscopes from blowing up. Things are not as universal as commonly thought

I mentioned 2.5inch drives not for their continues draw, but for their initial startup current draw. Sure these drives are very efficient at maintaining 5k/7k RPM, but spinning them up requires a lot of energy; more than even the full-power USB spec allows. Many tablets and smartphones nowadays have USB OTG. Can you stick a hdd in there? No you can't.

I'm the only person opposing this because I recognize that some of the "improvements" being suggested fall outside of the aim of this product and would only drive up production costs without any benefit. The 25/35 dollar price point was essential for the success. In essence nothing can go wrong without full-powered USB ports. What could possibly go wrong, anyway? "Oh my external hdd doesn't work, I guess I'll just use a hub like anyone would after all there's just 2 usb ports". The average raspi user will not be as tech illiterate as the average consumer. Please, don't underestimate the knowledge and skill of raspi users. I know you're meant to design consumer goods to survive the most stupid of mistakes and usage scenarios, but that's not what the raspi user will be like, otherwise they would have sold it encased from day1.

Nope fortunately I don't do any pro electrical wiring :D, I'm only a hobbyist

dapa79
Posts: 13
Joined: Mon May 21, 2012 5:55 am

Re: Minor improvements for a model C

Sun Aug 12, 2012 6:33 pm

reiuyi wrote:None of the points you mentioned matter to the educative goals. You're allowed to use raspi as whatever (it's yours, you bought it), but don't expect any hardware changes for non-critical aspects.

USB power: Works fine for its intended goal: keyboard and a mouse. Even usb sticks work!

Sound: It's about FM quality, way better than my old soundblasters. Nowadays PWM is almost always used for DACs (often in combination with a low-brand opamp). I don't see the issue again, it works fine for educative goals and there is a digital audio out if you really must. I'll just assume you never envisioned TDA1541-like quality.

Size: Not relevant for educative purposes at all. I can list tens of commercial devices that don't have mounting holes (seriously, open up your mobile phone or your mp3 player and there's never mounting holes in the modern ones). The low number of IO pins has to do with pcb routing, not size of the board. If you want more IOs, the entire thing would need to be redesigned as an 8 or 10 layer PCB and that's just too expensive (currently standard 6-layer). Although "connectors on all sides" is an often criticized point, it's not relevant for its purpose at all.

Model ID: This is just purely off-topic; an unreasonable demand. Raspi has gone all the way to supply some decoding codecs without there being any need, and now people are demanding even more? What on earth are you going to do with the h264 encoding license? There is no video-input on this thing and the camera connector is the only video-input and it requires specialized GPU drivers which you will never be able to produce yourself.

First of all I would like to say that I think the foundation has done a great job and I still think the R-Pi over all is a great product. I'll definitely be buying more of them. These comments are merely suggestions of what I think could be done to improve it. I hope others also give their five cents and hopefully there will be some sane ideas in this thread for the foundation to consider in future revisions. Even if it was designed with the educational market in mind, I think it would be unwise not to listen other users as well.

USB: As confimed by others in this thread, USB power really is a major issue.

Sound: I wasn't expecting audiophile quality sound, I just frankly didn't think it would be this bad with pops and noise at the start of each playback. Saving a very small amount in component costs during the initial design has led to a seemingly non-standard way of handling sound. It is now up to the foundation to engineer drivers, using GPU functionaly for PWM sound. There are cheap, of the shelf components with higher sound quality and existing Linux drivers. It's just a headache for current users as well as the foundation, that could have been avoided. Hopefully all the pops and DC-offset issues can be handled in improved drivers.

Size: I can't see the reason for having a minimal footprint when it comes to education. I think the current size comes from a combination of PCB cost and PR. It would have been difficult to keep that credit/business card reference if the card got any bigger. I think in a future revision mounting holes would be a great benefit in the educational scenario, where each card could be securely fastened onto a bigger plate, adding stability and rigidity. (and making it more difficult for the R-pies to disappear)

Codecs: With the CPU in R-Pi being quite slow, the big deal with the chosen SoC is the GPU. I think it would be a shame not to get access to all the multimedia features that make this platform so great. Now it seems the encoding license will probably be included in the camera module so there will be a way to get it. The Mpeg2 license is a commonly requested feature from non-educational buyers. I think most of them would be happy to spend a few extra dollars to buy this license if they could. It seems like there might be a software solution around the corner, but a HW solution would be even better. Perhaps the camera module "dongle" can be the solution in this case as well. I get that it is not reasonable to add the license cost to the default price of all R-Pis.

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 23083
Joined: Sat Jul 30, 2011 7:41 pm

Re: Minor improvements for a model C

Sun Aug 12, 2012 6:59 pm

As with every product launch, hindsight is always 20:20. There certainly are issues with the USB, both hardware and software. We made a lot of progress on the software side, and the power issue is being looked at.
The codec issue - MPEG2 is an old format, and expensive to licence, i'm sure something will be figured out
As to the size of the PCB, its a cost thing - the smaller the PCB, the cheaper it is (until you start using very small components). Credit card side is at the bottom of the cost curve, although since the volumes are now a lot higher than ever expected, a bigger board would be feasible at the same price point. BUT, as others have said, for its intended aim, it pretty much works ok, so any board reworks are not on the horizon.

James
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed. Here's an example...
"My grief counseller just died, luckily, he was so good, I didn't care."

User avatar
Vindicator
Posts: 314
Joined: Sat Sep 17, 2011 11:10 pm
Location: Susanville Ca USA
Contact: Website

Re: Minor improvements for a model C

Sun Aug 12, 2012 7:43 pm

What improvements that may be necessary are wholly dependent on the intended purpose of the device.
As an educational device this platform works ,it is not perfect but it works and the overall idea would not be to change it so that compatibility becomes an issue with each revision.

The power supply choice has been in my opinion is a big hang nail (not as in what they picked but in how it is working out in the real world) as there are many PSU's that just do not seem to work with the Raspi's and in some countries (like the US) the micro b usb configuration is not as wide spread as the UK and the EU but it is a UK product so that is the standard.

As for the hobbyist, were would the list stop for improvements more memory, faster CPU ,usb 3.0 ,quad core CPU's, 12 usb ports, 100 gpio pins, and on and on.

I could see possibly a purely hobbyist release of this platform in the future but I do not see the foundation as being involved in that release (other than licensing) and it will be a for profit venture so $35 dollars would be way out the window if that occurs.
If you are more worried about ,spelling, punctuation or grammar you have probably already missed the point so please just move on.

techpaul
Posts: 1512
Joined: Sat Jul 14, 2012 6:40 pm
Location: Reading, UK
Contact: Website

Re: Minor improvements for a model C

Sun Aug 12, 2012 9:15 pm

reiuyi wrote:
techpaul wrote:I note you did not quote my bit about 13A (thirteen Amp) sockets wired with 3A (three Amp) cable very teling.

Live in the real world a general computer with USB ports will have users plugging in any USB device that was the point of the standard.

The micro USB connector for power was a silly idea from day one as many micro USB cables are price manufactured down for SPECIFIC very low power devices and users will pick up any USB cable thinking they are all the same and many will put excessive volt drops and current limits.

As to power tracking I bet most of the 5V is actually in inner planes used only for power, so in effect is very wide.

Anyway a track capable of carrying 1A to the USB (two ports) is not as wide as you may think, it is around 0.4 to 0.5 mm wide for outer layers which it probably is at the moment or wider. It would have to be less than 1oz Cu to need wider than 1mm track on outer layers. Yes I lay out PCBs for my designs as well.

FYI last lot of USB 2.5 inch hard drives I used draw from USB power at ratring of 500mA last measured one was 400mA. The 500mA limit works with all self-powered USB 2.5 hard drives that I have used current job for one customer requires TEN of them they all work fine. 2.5 inch drives are laptop drives meant for low power usage and 5V only. Oh I have used them oin many systems of various vintages as well.

So far you are the only person who supports the current scheme I see no one else supporting in ANY thread anywhere. Having the attitude of it is fine is someone who does not understand the amount of things that can go wrong or has experience of real world users in their day to day life with electronic equipment.

I am someone who has for years had to design things to ensure users cannot do something beyond the spec with trying really hard, not doing what they are supposed to do.

I just hope you don't do any electrical wiring.

Allright allright I'll answer your domestic 13a limit. Where I live, people are often surprised they require a domestic three-phase power connection when installing a brand new all-electric kitchen. 3-phase is vastly superior to using mains with electric kitchen stoves, and where I live everyone has access to 3-phase to their home without much hassle. Even in modern homes, you cannot expect some electric things to "just work" when they're plugged in. Washing machines have their own electrical group and some hobbyists prefer a 1:1 isolation to prevent their oscilloscopes from blowing up. Things are not as universal as commonly thought

I mentioned 2.5inch drives not for their continues draw, but for their initial startup current draw. Sure these drives are very efficient at maintaining 5k/7k RPM, but spinning them up requires a lot of energy; more than even the full-power USB spec allows. Many tablets and smartphones nowadays have USB OTG. Can you stick a hdd in there? No you can't.

I'm the only person opposing this because I recognize that some of the "improvements" being suggested fall outside of the aim of this product and would only drive up production costs without any benefit. The 25/35 dollar price point was essential for the success. In essence nothing can go wrong without full-powered USB ports. What could possibly go wrong, anyway? "Oh my external hdd doesn't work, I guess I'll just use a hub like anyone would after all there's just 2 usb ports". The average raspi user will not be as tech illiterate as the average consumer. Please, don't underestimate the knowledge and skill of raspi users. I know you're meant to design consumer goods to survive the most stupid of mistakes and usage scenarios, but that's not what the raspi user will be like, otherwise they would have sold it encased from day1.

Nope fortunately I don't do any pro electrical wiring :D, I'm only a hobbyist
The best I can say is most of your comments show you did not understand my points

You think the avergae Raspi user is not as tech illiterate as the avergae consumer. Once it hits schools from personal experience the majority will be tech illiterate including a lot of the teachers
Just another techie on the net - For GPIO boards see http:///www.facebook.com/pcservicesreading
or http://www.pcserviceselectronics.co.uk/pi/

techpaul
Posts: 1512
Joined: Sat Jul 14, 2012 6:40 pm
Location: Reading, UK
Contact: Website

Re: Minor improvements for a model C

Sun Aug 12, 2012 9:19 pm

Vindicator wrote:The power supply choice has been in my opinion is a big hang nail (not as in what they picked but in how it is working out in the real world) as there are many PSU's that just do not seem to work with the Raspi's and in some countries (like the US) the micro b usb configuration is not as wide spread as the UK and the EU but it is a UK product so that is the standard.
Can I just say it is ONLY a standard for mobile phone chargers as to plug size to supposedly reduce the number of different phone chargers sold year on year. However each phone has different charging requiements and methods so we still seem stuck with same scenario.

It is a de facto standard now amongst tiny equipment (cameras, mp3 players, ereaders, some tablets) for the link cables, and their VERY low power requirements.

Other than that the only way that connector size is a standard is that it is one of connector standard sizes for USB.
Just another techie on the net - For GPIO boards see http:///www.facebook.com/pcservicesreading
or http://www.pcserviceselectronics.co.uk/pi/

techpaul
Posts: 1512
Joined: Sat Jul 14, 2012 6:40 pm
Location: Reading, UK
Contact: Website

Re: Minor improvements for a model C

Sun Aug 12, 2012 9:23 pm

dapa79 wrote:Size: I can't see the reason for having a minimal footprint when it comes to education. I think the current size comes from a combination of PCB cost and PR. It would have been difficult to keep that credit/business card reference if the card got any bigger. I think in a future revision mounting holes would be a great benefit in the educational scenario, where each card could be securely fastened onto a bigger plate, adding stability and rigidity. (and making it more difficult for the R-pies to disappear)
From things disappearing at schools oiver the years, it will not just be the Pis it will be SD cards, cables, gpio attachments the works.

Having seen over the years that at schools, when mice had roller balls they always disappered always keep a bag full of spares. keys taken from keyboards. Odd cables and all sorts go missing.

In one case a hardware PS2 keystroke logger nefariously added to a system.
Just another techie on the net - For GPIO boards see http:///www.facebook.com/pcservicesreading
or http://www.pcserviceselectronics.co.uk/pi/

W. H. Heydt
Posts: 10625
Joined: Fri Mar 09, 2012 7:36 pm
Location: Vallejo, CA (US)

Re: Minor improvements for a model C

Sun Aug 12, 2012 9:53 pm

The point has been made several times in this thread that any "upgrade" to the Model "B" won't include a PCB revision. There is, though, one potential improvement was part of the prototype and "alpha" boards that didn't make it to production because of cost. That's an enclosed shell SD card connector.

If a "Model C" (or even just a "Model B.2") were made, a better SD connector should certainly be considered to make the cut.

techpaul
Posts: 1512
Joined: Sat Jul 14, 2012 6:40 pm
Location: Reading, UK
Contact: Website

Re: Minor improvements for a model C

Sun Aug 12, 2012 10:13 pm

W. H. Heydt wrote:The point has been made several times in this thread that any "upgrade" to the Model "B" won't include a PCB revision. There is, though, one potential improvement was part of the prototype and "alpha" boards that didn't make it to production because of cost. That's an enclosed shell SD card connector.

If a "Model C" (or even just a "Model B.2") were made, a better SD connector should certainly be considered to make the cut.
WIthout an 'enclosed' GPIO connector there is a problem for school take up, or even if they get them finding them too difficult to use reliably, cursory measurements show it can fit just.

Waiting for a spare Pi for this exact mod to be done
Just another techie on the net - For GPIO boards see http:///www.facebook.com/pcservicesreading
or http://www.pcserviceselectronics.co.uk/pi/

jb1963
Posts: 10
Joined: Sat Aug 04, 2012 12:20 am

Re: Minor improvements for a model C

Sun Aug 12, 2012 11:51 pm

(Sorry if this post appears to be repeating previously made points, I typed it before re-logging in and seeing all these new replies...)

I have to start this post by saying something that should be repeated again and again: what the people behind the Raspberry Pi Foundation have done is incredible and is deserving of all accolades. I do now want to come across as ungrateful -- in fact, I am more in awe of what they have done than not. I mean, the core of a mostly complete computer for 35$ ? That would have been unthinkable not that long ago!

Now, to come back to our regular programming: the fact that people are arguing about power issues with the usb ports, even that power issues might prevent the addition of two more usb ports, or that some are modifying the power circuit(s) is an indication that this aspect of the Pi could be made more robust. I am not saying we should have the power budget of a full-fledged workstation, but rather that the experiences of various users should be taken into account and a potential source of frustration and problems should be looked into. The Foundation should improve things within the limits of the possible, then let people know what the power constainsts of the Raspberry Pi are and voilà!

Such and upgrade should target the 'model B' and, especially an hypothetical 'model C'.

I understand the motivations behind the will to cut costs as much as possible, but beyond a certain point, it can become counter-productive: a less robust and functional end-product. Apparently, there is always a way to cut costs, but I believe we are at a lower limit that should not be gone beyond.

This is why I say forget the 'model A': IMO, the value of a computer is in its I/O capabilities, and the 'model B' is the strict minimum that end-users should experience. These days, two USB ports and a LAN connector are definitively not unnecessary "bell and whistles".

So, the 'model B' should become the new 'model A' and a possible 'model C' should become the... 'new B'. The fact that a 'model C' would have to use the same PCB limits what upgrades can be done to the Pi. This is why I would now say that any major modification could be done via daughter boards, leaving the main board "intact".

On the main board, if Broadcom offers a plug-compatible SoC containing twice the memory and the capacity of running faster (800, 900MHz ?), that should be used to be the main difference between the two models of Raspberry Pi's (sic). Of course, if someone finds a usb+ethernet controller chip that implements ethernet in a more efficient manner (ethernet-through-usb cannot be the best way of doing things...) and is plug-compatible or easy to retro-fit in some cost-effective fashion, that should also be used...

As for daughter boards to add functionalities to the Pi, of which I already see at least two, they should permit the usage of :
(1) a ribbon cable to add extrior modules such as, but not limited to the Gert Board;
(2) heatsinks such as (https://tindie.com/ellisgl/raspberry-pi ... -sink-kit/ -- an example, not an endorsement) for those who would prefer their Pi's (sic) somewhat protected from overheating.

One of these daughter board should add a, IMO, much needed real time clock + battery as well as updated firmware that would unlock MPEG-2 decoding in the SoC. The other one would add the aforementionned camera module... and the updated firmware mentionned above. Other capabilities such as an S/PDIF-out, a VGA connector, et al, could also be discussed.

There is so much potential in the Pi that its limitation are even more frustrating, considering they don't have a purely technical origin...

Cheers.

User avatar
Lob0426
Posts: 2198
Joined: Fri Aug 05, 2011 4:30 pm
Location: Susanville CA.
Contact: Website

Re: Minor improvements for a model C

Mon Aug 13, 2012 1:35 am

@jb1963:
The B model was really targeted as a developer release board. The A model is the Board the Foundation is really putting its chips on for educational programming. That is why it states that the Raspberry Pi is a $25 box. "An ARM GNU/Linux box for $25. Take a byte!". Personally I think most schools are going to go the extra and buy the B models. Especially here in the U.S., if they catch on herre. Most of our schools have extensive network resources available. Now if those resources were used for something other than "Keyboarding" which is about on level or below U.K. ICT. Again the A model is where the foundation believes its sales to education are going to be. I think the third world sales of A models is going to be larger. There are a lot of areas out there that do not know what a "network" is. Of course Smart Phones are changing this at a very rapid pace. A programming "App" might really be the answer if Cell Phones OS's were not so locked down.

With all that said I still cannot wait for the release of the A Model. By the way, the A model will not have the over heated LAN chip problem, No LAN9512 chip! :lol: It would be nice if they were to change to a larger poly fuse for it, as it only has one port. But if you want anything more than a Keyboard then you will have to have a powered hub anyway. Wireless problems due to the chipset fights between hubs and the LAN9512 will be gone. Wireless should be a breeze then. I already have plans for the A model that include a Soldering iron and some private time alone with a poor little A model board. :twisted: :idea:
512MB version 2.0 as WordPress Server
Motorola Lapdock with Pi2B
Modded Rev 1.0 with pin headers at USB

http://rich1.dyndns.tv/
(RS)Allied ships old stock to reward its Customers for long wait!

User avatar
Vindicator
Posts: 314
Joined: Sat Sep 17, 2011 11:10 pm
Location: Susanville Ca USA
Contact: Website

Re: Minor improvements for a model C

Mon Aug 13, 2012 2:22 am

Techpaul I am not sure what your goals are but as to what you quoted I did not elicit anything other than that micro b usb was the standard the foundation chose to put on the Raspi.
In the US there is many proprietary connectors still being used for chargers were this has been vastly reduced in Europe (which in my opinion should be done here also) to a more common connector to help reduce E waste.
The only thing proprietary connectors do here is make companies more money in selling accessories.

Regardless I have as much as you have seen many post of PSU's that are not successfully driving a Raspi to the point of that is usually the first troubleshooting step is to try another supply, This could be the supply or the cord from the supply the Raspi Etc.
If you are more worried about ,spelling, punctuation or grammar you have probably already missed the point so please just move on.

jb1963
Posts: 10
Joined: Sat Aug 04, 2012 12:20 am

Re: Minor improvements for a model C

Mon Aug 13, 2012 3:21 am

@Lob0426:

Ack! I know the model A is cheaper than model B, but come on -- how broke can you be if you cannot afford 35$? I believe the model B is already at the minimum for usefulness. Wanting to pay only 25$ for the model A is a very bad move that will end up being counter-productive to the foundation's goals to help schools, that unit being so lacking, IMO. The LAN and second USB ports are very well worth the extra 10$.

User avatar
Lob0426
Posts: 2198
Joined: Fri Aug 05, 2011 4:30 pm
Location: Susanville CA.
Contact: Website

Re: Minor improvements for a model C

Mon Aug 13, 2012 5:44 am

I have three B models with a fourth on order from RS if I ever see it. An A model would be perfect for a Lapdock. The power savings of having the LAN9512 gone could be worth it also. If you add the fact that there will be no wred/wireless fight, Bonus. I also have been working on another project that the A model will be perfect for. If all else were to fail I have Panda Board ES. Or the dual boot Win7/Ubuntu netbook, or the Dell XPS 420 Q6600, or the Dell XPS 8300, or..... Ok you should get the point. So no the price is not the deciding factor as to what model I choose or use. If you plan to go wireless you really do not need the Ethernet port. Either way you need a powered hub, so what is the real difference. I do have one B model RasPi now that can power a USB HDD in a headless config. Replaced the poly fuses.

Some places an A model is better than the B model:
It may be possible to run a RasPi OTG without the LAN chip there.
No LAN9512; this equates to reduced power usage. The Lan chip is one item that they are having trouble shutting down to a low powered mode.
Example; my Lapdock runs for about 3 hours with a B model, this may be extended another hour under operation, or more at idle.
My Lapdock is running wireless and has its own hub so why worry about a second USB port or the Ethernet.

.@jb1963 we are going to break open that box you are stuck in if we have to do it with you kicking and screaming! :lol: ;)
512MB version 2.0 as WordPress Server
Motorola Lapdock with Pi2B
Modded Rev 1.0 with pin headers at USB

http://rich1.dyndns.tv/
(RS)Allied ships old stock to reward its Customers for long wait!

User avatar
Vindicator
Posts: 314
Joined: Sat Sep 17, 2011 11:10 pm
Location: Susanville Ca USA
Contact: Website

Re: Minor improvements for a model C

Mon Aug 13, 2012 5:44 am

Coming into our school year soon and there are donation locations for school supplies for kids in need in every community in the US so I would say that $35 as well as $25 is out of many school children's budget.
I know after my wife recently having had a stroke that funds are exceptionally tight as we try to pay off the bills that my insurance did not cover and her recurring physical therapy which is a continuous drain also so I would argue that even $25 may not be a burden for you or even I, it may well be a huge hurdle to children and their families that already do not have the means to own a computer at all.
I do agree as I have all along that I would not be surprised if schools utilize the B model more than the A if they have the choice.

The single usb port with a 100ma limit on an A model for all intensive purposes does create a major problem to connect a mouse and keyboard without a hub.
The Ethernet port for a child that neither has a computer and probably no internet connectivity is not much of a problem.
If you are more worried about ,spelling, punctuation or grammar you have probably already missed the point so please just move on.

User avatar
RaTTuS
Posts: 10381
Joined: Tue Nov 29, 2011 11:12 am
Location: North West UK

Re: Minor improvements for a model C

Mon Aug 13, 2012 12:54 pm

I have uses for a model A.
there are things that I don't need
i.e. 2 USB ports and Ethernet I can use 1 just fine.
and that price difference would be very useful in some circumstances
How To ask Questions :- http://www.catb.org/esr/faqs/smart-questions.html
WARNING - some parts of this post may be erroneous YMMV

1QC43qbL5FySu2Pi51vGqKqxy3UiJgukSX
Covfefe

techpaul
Posts: 1512
Joined: Sat Jul 14, 2012 6:40 pm
Location: Reading, UK
Contact: Website

Re: Minor improvements for a model C

Mon Aug 13, 2012 1:18 pm

Vindicator wrote:Techpaul I am not sure what your goals are but as to what you quoted I did not elicit anything other than that micro b usb was the standard the foundation chose to put on the Raspi.
In the US there is many proprietary connectors still being used for chargers were this has been vastly reduced in Europe (which in my opinion should be done here also) to a more common connector to help reduce E waste.
The only thing proprietary connectors do here is make companies more money in selling accessories.

Regardless I have as much as you have seen many post of PSU's that are not successfully driving a Raspi to the point of that is usually the first troubleshooting step is to try another supply, This could be the supply or the cord from the supply the Raspi Etc.
Firstly it is the wording 'standard', the USB micro B is the Pi power connector, the only place this is a standard is for phone chargers, it is not a standard by any other means.

It may be the foundation's internal ORGANISATION standard.other than that it is not a standard. If you think it is find the non-foundation document stating it is a standard for anything other than phone chargers.

Standards are written documents, company and defacto standards are working practises that are wrongly called standards.

Then there are the misquoted standards like RS232, which some people think actually states what signal names and protocols are used, it only defines electrical signalling levels, and until Revision D then stated some common connector types used. What most people mean is UART start/stop communication using RS232 levels over specific cables and connectors. Most of the connectors people called RS232 connectors were actually International telephone companies standards ITU V24 for what connections and signlas, as well as handshaking protocols the modems had to have to connect to their phone lines.
Just another techie on the net - For GPIO boards see http:///www.facebook.com/pcservicesreading
or http://www.pcserviceselectronics.co.uk/pi/

toxibunny
Posts: 1382
Joined: Thu Aug 18, 2011 9:21 pm

Re: Minor improvements for a model C

Mon Aug 13, 2012 1:20 pm

I'd be very happy with a model A too.
note: I may or may not know what I'm talking about...

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 23083
Joined: Sat Jul 30, 2011 7:41 pm

Re: Minor improvements for a model C

Mon Aug 13, 2012 1:44 pm

techpaul wrote:
Vindicator wrote:Techpaul I am not sure what your goals are but as to what you quoted I did not elicit anything other than that micro b usb was the standard the foundation chose to put on the Raspi.
In the US there is many proprietary connectors still being used for chargers were this has been vastly reduced in Europe (which in my opinion should be done here also) to a more common connector to help reduce E waste.
The only thing proprietary connectors do here is make companies more money in selling accessories.

Regardless I have as much as you have seen many post of PSU's that are not successfully driving a Raspi to the point of that is usually the first troubleshooting step is to try another supply, This could be the supply or the cord from the supply the Raspi Etc.
Firstly it is the wording 'standard', the USB micro B is the Pi power connector, the only place this is a standard is for phone chargers, it is not a standard by any other means.

It may be the foundation's internal ORGANISATION standard.other than that it is not a standard. If you think it is find the non-foundation document stating it is a standard for anything other than phone chargers.

Standards are written documents, company and defacto standards are working practises that are wrongly called standards.
On the Raspi, the power connector is Micro USB. That's the Raspi 'standard', if you want to be picky. It could easily have been a barrel connector or something custom like Apples. It isn't. It's micro USB. Chosen because it's used in Europe (By a European Union directive) for smartphone chargers, giving a quick and easy access to a lot of chargers. If your charger is capable of supplying the required current, then it all works fine. If your charger states it can supply and doesn't, then that's a problem with the charger, not a problem with the choice of the connector. I'm really failing to see what the problem is here. It's just a connector.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed. Here's an example...
"My grief counseller just died, luckily, he was so good, I didn't care."

alexchamberlain
Posts: 121
Joined: Thu Jun 14, 2012 11:20 am
Location: Leamington Spa, UK
Contact: Website

Re: Minor improvements for a model C

Mon Aug 13, 2012 2:25 pm

jamesh wrote: On the Raspi, the power connector is Micro USB. That's the Raspi 'standard', if you want to be picky. It could easily have been a barrel connector or something custom like Apples. It isn't. It's micro USB. Chosen because it's used in Europe (By a European Union directive) for smartphone chargers, giving a quick and easy access to a lot of chargers. If your charger is capable of supplying the required current, then it all works fine. If your charger states it can supply and doesn't, then that's a problem with the charger, not a problem with the choice of the connector. I'm really failing to see what the problem is here. It's just a connector.
I don't disagree with you jamesh; great idea to use chargers people already have. I think the problem techpaul is trying to communicate is that the public at large are stupid. They see a charger with a Micro B connector and think it will work because the connectors are the same; just as HDMI just works, because the connectors dictate the electrical protocol on which devices communicate. The problem is here that the Raspberry Pi doesn't give any indication that power is a problem, before doing strange things. Then, the stupid public assume the Raspberry Pi is broken, because their charger works in their phone after all.
Developer of piimg, a utility for working with RPi images.

AlArenal
Posts: 141
Joined: Sun Feb 26, 2012 6:58 pm
Location: Germany
Contact: Website

Re: Minor improvements for a model C

Mon Aug 13, 2012 4:58 pm

jamesh wrote:On the Raspi, the power connector is Micro USB. That's the Raspi 'standard', if you want to be picky. It could easily have been a barrel connector or something custom like Apples. It isn't. It's micro USB. Chosen because it's used in Europe (By a European Union directive) for smartphone chargers, giving a quick and easy access to a lot of chargers. If your charger is capable of supplying the required current, then it all works fine. If your charger states it can supply and doesn't, then that's a problem with the charger, not a problem with the choice of the connector. I'm really failing to see what the problem is here. It's just a connector.
You're right but a charger is not a PSU. A phone charger is usually kept as simple as possible to be as cheap as possible. Therefore it's build with charging in mind and for charging you don't need to be too close to any standard, it will work no matter what. But the Pi is not a rechargeable battery, it is a computer and it needs a PSU that is reliable and works within certain specifications. That's why there's so many power-related problems.

The idea of using something as PSU that most people already own in the EU is great. But the foundation's engineering team overestimated the capabilities of those chargers and did not do enough testing. And it's not just the mobile phone chargers, sometimes problems come down to the cables. Some seem to be built for data only and do a bad job at transferring power. Some are too long or whatever. They work well for charging, but not as a connection cable between PSU and computer.

So in the end you end up buying a PSU and a cable anyway, just to make sure any issue you might have is not related to your charger.

User avatar
Lob0426
Posts: 2198
Joined: Fri Aug 05, 2011 4:30 pm
Location: Susanville CA.
Contact: Website

Re: Minor improvements for a model C

Mon Aug 13, 2012 7:39 pm

The Micro B USB connector has limitations of its own. It can only supply about 1.2 amps total unless you use all four pins, it doesn't. The chargers themselves vary widely in output and quality of that output. This is not only a problem with the micro USB charger it is a problem with all "Cell Phone" chargers. With the original power scheme of 6v to 20v you would not have had anywhere near as much problem finding a decent power supply (wall-wart), as the regulator circuit on the original design smoothed it all out very well. The new design relies upon you having a good quality of charger. I worry that these problems will be even worse when RasPi hits the third world education systems. There will always be that need to cut costs and a box of chargers, or keyboards, or Mice or USB hubs, at a low price could ruin the chances of the RasPi completing its mission. These are all arguments that have been hashed out before and are pretty much moot at this point, but they are still valid.

The Raspberry Pi is a wonder of a device in its own right. I hope that a C model will appear in the future. I also hope that an eye is being kept on the "MODS" that are being carried out by different RasPi owners. Some of these ideas have great potential as data for a future C model design. Some Data that should be closely monitored, is the number of B models versus A models that educators buy. Me and Vindicator, and others, believe that the B model will be the model of choice for most schools.

In these type of discussions you are going to always get the person that wants a Tegra3 with 1GB and four USB plus Gigabit Ethernet and wireless thrown in besides for $35. And do not forget the USB 3.0 either. The rest of us really just want a little more or a fix to the problems that have been found already in the current RasPi.

The bottom line is if you want all of the stuff that is in a Panda Board or a Beagle Board or in any other board you will pay that same type of price for it. That is just how it is. None of these other boards have came anywhere near the sales figure of the RasPii that are already out in the world and none of them will ever catch up. WHY? Well its the price! almost anyone can find $25 or $35 to try out a RasPi. Even at $99 a Beagle Bone is in a different league for most. Raspi has already had an impact on the inexpensive computing device industry. There are more choices now than there were a year ago. and more are being brought out all the time. This trend will continue. Intel and AMD are feeling the pressure of cell phones, tablets and the Raspi is not going to make it any easier on them either. Just think there could be a million RasPii by Christmas. The first production models are only a few months old now.

For those of you that are discouraged with the production rate of the Raspberry Pi, just be glad you are not trying to get a Beagle Board-xM. I tried and failed!
512MB version 2.0 as WordPress Server
Motorola Lapdock with Pi2B
Modded Rev 1.0 with pin headers at USB

http://rich1.dyndns.tv/
(RS)Allied ships old stock to reward its Customers for long wait!

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 23083
Joined: Sat Jul 30, 2011 7:41 pm

Re: Minor improvements for a model C

Mon Aug 13, 2012 9:01 pm

alexchamberlain wrote:
jamesh wrote: On the Raspi, the power connector is Micro USB. That's the Raspi 'standard', if you want to be picky. It could easily have been a barrel connector or something custom like Apples. It isn't. It's micro USB. Chosen because it's used in Europe (By a European Union directive) for smartphone chargers, giving a quick and easy access to a lot of chargers. If your charger is capable of supplying the required current, then it all works fine. If your charger states it can supply and doesn't, then that's a problem with the charger, not a problem with the choice of the connector. I'm really failing to see what the problem is here. It's just a connector.
I don't disagree with you jamesh; great idea to use chargers people already have. I think the problem techpaul is trying to communicate is that the public at large are stupid. They see a charger with a Micro B connector and think it will work because the connectors are the same; just as HDMI just works, because the connectors dictate the electrical protocol on which devices communicate. The problem is here that the Raspberry Pi doesn't give any indication that power is a problem, before doing strange things. Then, the stupid public assume the Raspberry Pi is broken, because their charger works in their phone after all.
The 'problem' would arise though, whatever connector was supplied. If we had used a barrel connector, people would be forced to go out and buy a power supply, again, with the same problem - they need one that can supply the appropriate current. Using USB means that people *may* have a power source that works already. If they don't they have to get one. Most people are not so stupid that they cannot read the back of a power supply and get the current rating off, which they woudl ahve to do whatever the connector!
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed. Here's an example...
"My grief counseller just died, luckily, he was so good, I didn't care."

Return to “General discussion”