Yelvieman
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Second impressions

Sun May 27, 2012 7:41 pm

My background is started writing programs on Commodore PETs, ZX81, Vic-20 including some assembler, a bit of a gap, IBM mainframes using Cobol, PCs using a variety of languages including C++, HP-UX using C and more recently C# and MS-SQL so on and off programming for over 30 years and have been paid to program for most of those. I'm not a total tech head but I do know what I'm doing in most cases.

I spent yesterday playing with the Pi and was quite happy with it I got raspbmc installed, it was slow but I guess with some tweaking it will be usable. Debian with LXDE was too slow to be of any practical use so I reverted to the command line and spent a good few hours installing apache & php and getting to grips with linux.

My intentions at this point were that I'd use it to learn PHP and see what I could do with it in terms of automation etc. I was going to install MySQL but realised that there was only about 200Mb free on the SD card so started looking at using a USB flash drive. That was when the problems started.

As I still had mouse and keyboard plugged in I thought I'd use an old hub. As soon as I did that things started freezing and getting a bit flakey. I realised that this meant I probably needed to get a powered hub. Being Sunday I went to PC World with the list of working hardware/peripherals from the wiki. In the end I bought a logitech wireless keyboard with tracker pad, netgear wifi adapter and a powered hub all of which the wiki said worked.

I put a post on here earlier explaining a problem with the wifi. Turns out if I have just the wifi and a normal keyboard plugged in it works. Plug it in via the hub it doesn't work. Plug it in directly with the wireless keyboard - doesn't work.From reading posts on here it sounds like this is because the usb devices are pulling to much power which is causing these problems.

I'm sure someone will mention USB standards and hubs and blah blah blah. That's not the point. It appears that the Raspberry Pi is very temperamental with the load on the USB ports and it causes things to stop working.

In addition to this it might reboot properly or sometimes it wont - given the poor graphical performance I was going to use this as a headless 'server' but can't really do that if I can't trust that it will boot up when needed.

I love the concept of the Raspberry Pi )cheap computing for kids to learn programming) but don't think that it will catch on with non-techies. I know I could get things cheaper than in PC World but so far I've spent nearly £100 not including SD Card or USB flash drive on a very slow, temperamental computer that only works practically with 2 usb devices that can't do flash. My kids netbooks were about twice that price and have 160Gb hdd and could easily run a virtual machine running Debian.

Perhaps someone can convince me that I've got things wrong and it just needs a small tweak to get it all going, I might give this another go but otherwise the pi will be going on the bay!

KaelaStreet
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Re: Second impressions

Mon May 28, 2012 12:42 pm

Hey, Im on the same wavelength. I have the Rasperry PI, hooked up and running as far as the command prompt. I feel if this is only going to work on Linux or Python, then its actually a painful way of forcing a new user to learn a little used language favoured by a few techies.

I don't doubt there are many instances and applications where Linux shines, but the normal switch on and do something type of hardware is not one of them. Notebooks, Windows, Macbooks iPads all are ready to do something within a few moments of switching on. None of them require you to learn a new language before they can be used.

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rurwin
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Re: Second impressions

Mon May 28, 2012 1:32 pm

This is the Developer's Release. It's for developers. This release of Debian is what was hashed together to test the Beta boards. There are major holes in the packages that are provided. The whole point of this release is to get the board out to developers who can fill those holes and find and fix any problems with the distribution, while they feed back any difficulties found with the hardware, in case changes need to be made in face of hardware and configurations that the designers had not tested.

It is expected to be slow and buggy. It is expected to come with no documentation. It is expected to be as user-friendly as a cornered rat. It's for developers.

*sigh*

The fact that you have bought it expecting something else is nobody's problem but yours. If you are willing to be a pioneer then stuck around and we'll give you some pointers and use you to to test stuff. If that's not what you want, the door's to your left. Feel free to eBay the Raspberry. (At the moment you'll probably make a profit.)
the normal switch on and do something type of hardware is not one of them
You mean like your router, your telephone and your television?
None of them require you to learn a new language before they can be used.
You've spent something like a decade or more learning Windows. Have you ever seen anyone encountering it for the first time? Anyway, Linux is stick-shift, not a hovercraft.

Yelvieman
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Re: Second impressions

Mon May 28, 2012 2:04 pm

I don't mind the fact that the packages are slow and possibly buggy, I can live with that and it can be fixed with new releases. I understand that there is no such thing as a free lunch and that for £30 I wasn't going to get a computer with the same power as the latest Intel/Mac.

Some pointers would be useful, looks like very few of the 180ish that've read this thread have bothered to scan further down to see my other thread and amazingly none of the 49 that viewed my thread about the netgear wifi adapter have any suggestions.

However, I think there is a serious problem with the hardware, looking in the troubleshooting section there are a number of issues that seem to have a response of '...the usb device is drawing too much power' and some of them are when people have just a mouse/keyboard plugged in. USB is the defacto standard for connecting peripherals and there are all sorts of USB devices out there that people will want to use with the pi but if we are stuck to only using a very small subset of those the project will never break out of the geek niche.

Give me some pointers and I am happy to do some testing to assist the community.

tumblebomb
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Re: Second impressions

Mon May 28, 2012 2:28 pm

Maybe you want to try a virtual machine running on a standard desktop/laptop? Theres a lot of good sites to learn from the ground up how to work Linux. try Linux zoo: http://linuxzoo.net/

There will be easy things to do and hard things to do on the RaspPi. Just go in baby steps first and you'll be fine. Use the online magazine for some examples.

I'm no Linux expert but I've used it enuf to be familiar. I know i have a lot to learn for example using my wireless dongle on a a modern PC didn't work. The provided Linux driver didn't compile. I found my old dongle and it worked first time. So I have some learning to do to get the new one fixed. I come from the background of tinkering with electronics so don't even think about it much.
Mine will be arriving this week.

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piglet
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Re: Second impressions

Mon May 28, 2012 2:45 pm

If you're having problems with the powered hub, you may need to do what a number of us have successfully done: Stop the powered hub from sending power to the Pi.

Some people have "cut the red wire" in the data cable from the hub to the Pi. I used a pair of small pliers and pulled out pin 1 on the cable's connector.

There is an issue of the Pi not liking the +5v from the hub into the Pi USB ports.

Yelvieman
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Re: Second impressions

Mon May 28, 2012 3:22 pm

@tumblebum
I'm quite happy learning Linux and even looking forward to that. I won't bother with the VM though as things that work on the VM won't necessarily work on the Pi and if I'm not using the Pi I might as well recommission an old PC or laptop as a linux box.

@piglet - finally some advice.
I'm going to try your suggestion about cutting the red wire (no the blue wire !) although I still believe this is a design fault that the Pi should really cater for.

Not sure if I'll get time to do this tonight but will see what I can do and update this thread.

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SN
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Re: Second impressions

Mon May 28, 2012 4:33 pm

piglet wrote:If you're having problems with the powered hub, you may need to do what a number of us have successfully done: Stop the powered hub from sending power to the Pi.

Some people have "cut the red wire" in the data cable from the hub to the Pi. I used a pair of small pliers and pulled out pin 1 on the cable's connector.

There is an issue of the Pi not liking the +5v from the hub into the Pi USB ports.
This IS annoying me because it makes it damn near impossible to fire up my raspi in a controlled manner.

I bought a 3.5amp powered 7 port pluscom hub (worked for others on here) but I'm damned if I can get the simple combo of:-

- a raspi
- usb keyboard
- usb mouse
- usb belcom wireless adaptor (zd1211 underneath - and being problematic too)

running together - I've tried many but not all combos yet - anyone got something similar - what is your setup?

I am prepared to butcher the USB A-B cable if I have to....

Also I have two power combos - an HTC and an HP iPaq charger - the former gives me 4.76v between TP1/2 when WLAN/Kb connected and the latter onlt 4.72V and i DOES MATTER
Steve N – binatone mk4->intellivision->zx81->spectrum->cbm64->cpc6128->520stfm->pc->raspi ?

tufty
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Re: Second impressions

Mon May 28, 2012 5:51 pm

Yelvieman wrote:However, I think there is a serious problem with the hardware, looking in the troubleshooting section there are a number of issues that seem to have a response of '...the usb device is drawing too much power' and some of them are when people have just a mouse/keyboard plugged in. USB is the defacto standard for connecting peripherals and there are all sorts of USB devices out there that people will want to use with the pi but if we are stuck to only using a very small subset of those the project will never break out of the geek niche.
Correct. 100% correct. There is a very major design flaw in the way that the pi handles power (and above all, power to usb devices). It's becoming more and more obvious that this is the case, hundreds of thousands of /broken/ devices are shipping, and it's high time someone from the foundation piped up about it.

Simon

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mahjongg
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Re: Second impressions

Mon May 28, 2012 7:07 pm

Its not a big deal, they simply have fitted too low amperage fuses, thats all.
these fuses are barely enough for 100mA devices, but many people try to connect USB devices needing twice as much or more, that trips the fuses, and they do not recover immediately.
You could simply bypass the fuses if you feel adventurous.
A hub feeding back power isn't a problem in itself, but the PI cannot be powered this way, as there are these 100mA fuses in the way, but using an output from the hub to power the front power entry shouldn't be a problem, unless the HUB itself limits its output power to a port to less than what a PI uses.

Yelvieman
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Re: Second impressions

Mon May 28, 2012 7:40 pm

@mahjongg - I wouldn't say it isn't a big deal. I shouldn't have to 'bypass the fuses' because I'm 'feeling adventurous'. Every other piece of computing equipment that I have that has USB works out of the box without needing to bypass fuses or cut red wires. This Pi might only be £30 but by the time you factor the other bits and pieces in it costs a lot more - at least half the cost of a netbook that will work and provide the same 'learning' experience. If I had wanted to get my hands that dirty I would've bought myself an electronics kit.

@piglet - I've cut the red wire and the hub is no longer feeding power back to the Pi as the red power light is no longer lit when only the hub is plugged in but things are still not good. I have only got power, HDMI cable, the hub plugged in with wireless keyboard, wifi and a flash drive - surely not too much to ask and now it is giving errors along the lines of :

eth0: Failed to read register index 0x00000114
eth0: Failed to write register index 0x00000114
wpa-supplicant: wpa-ssid "myssid" failed!
wpa-supplicant: wpa-psk **** failed!

I give up. I was looking for a little project but this thing just doesn't want to work properly and I'd rather spend my time doing something else than working around design faults.

Unless the Pi improves by a great margin I really can't see who is going to use it. If you need to be that much of a techie to use it the chances are you have an old PC or 2 knocking around that would work far better for teaching your children and if you aren't techie why would you want to put up with these problems.

I'm going to sell the Pi, if anyone is near Plymouth or Totnes and wants it for cost they are welcome just PM me and we'll arrange delivery or pick up. You can even have the Logitech K400 keyboard and Netgear Wifi adapter for what I paid if you really want.

jamesh
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Re: Second impressions

Tue May 29, 2012 2:23 am

I was going to give you an email address of someone who would be able to help you, but you have already given up so I'm thinking the help wouldn't work for you anyway.

Sorry you feel the device isn't for you, but as its still considered a dev board at this stage, and lot of people are using the Raspi fine perhaps it really isn't for you.
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frying_fish
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Re: Second impressions

Tue May 29, 2012 7:01 am

I have to admit, all the USB devices (including my microsoft wireless comfort curve desktop 6000) have worked out of the box. A couple of wired keyboards, the wireless desktop combo I mentioned, several USB mice, and a Speedlink SL-6399 IR remote.

I wasn't expecting the IR remote to be picked up out of the box, but it did, and was a lot simpler than it was to setup in windows.

The "not enough power output" on the USB ports is not really a fault. The USB standards say devices have to allocate power in units of 100mA. Only 100mA has to be given out, and the device can negotiate for more than 100 mA. If the host denies the extra units then the device has to stick with 100mA.

Issues with the powered hubs sending power back down the data line is a bad design in the USB hub, and for devices that don't run at such low power, and tight to its power constraints this isn't an issue.


As you say, this device probably isn't for you, but it is clearly labelled as a dev board still, and why you would expect anything different is not the foundations fault.

tufty
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Re: Second impressions

Tue May 29, 2012 7:16 am

frying_fish wrote:The "not enough power output" on the USB ports is not really a fault. The USB standards say devices have to allocate power in units of 100mA. Only 100mA has to be given out, and the device can negotiate for more than 100 mA. If the host denies the extra units then the device has to stick with 100mA.
Ummm. In what way, "not really a fault"?

The ports are polyfused at 140mA. This should be enough to allow them to source 100mA with ease.

The Apple wired keyboard is rated at 100mA maximum (50mA + 50mA), has been measured as drawing < 25mA in reality. 100mA should be in spec, 25mA certainly is. However, it doesn't work with the Pi. Voltage drop at 25mA is enough to kill it. The problem is not "user error".

Yelvieman
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Re: Second impressions

Tue May 29, 2012 7:27 am

@frying_fish - There are standards definitions and then there are the real world devices. Back in the day I bought a rather expensive CD player that refused to play some CDs that weren't Red Book compliant where all the cheap as chips players did. All my devices worked near enough out of the box, I had to root around to install the drivers for the wifi adapter but it worked, it was just when more than 2 devices are used it starts going wrong.

I'm not asking for this Pi to play ball with 16 USB devices like I've seen one person on here say they are doing, all I want is wireless keyboard, wifi adapter and a flash drive - is that really too much to ask for?

@jamesh - I put a post on the official forums for the device and have had precisely no help on that post in over 36 hours and 98 views of the thread, 468 views on this thread in just over 30 hours. I've had one piece of useful advice from piglet about cutting the red wire but that didn't actually help me.

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nick.mccloud
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Re: Second impressions

Tue May 29, 2012 7:56 am

Yelvieman wrote: @jamesh - I put a post on the official forums for the device and have had precisely no help on that post in over 36 hours and 98 views of the thread, 468 views on this thread in just over 30 hours. I've had one piece of useful advice from piglet about cutting the red wire but that didn't actually help me.
I think you've usefully summarised why we are struggling to help you.

robwriter
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Re: Second impressions

Tue May 29, 2012 6:05 pm

I get that the Pi is new and so people should have low expectations, but if we're in to the realms of soldering fuses, hacking up cables and rewriting USB drivers then it's going to put people off. There's a lot of people who won't do that, but will do useful development.

And I'm not really sure all of the problems being faced are due to power - I have a MS wireless kb/mouse that suffers the sticky keys issue regardless of what I use to power the Pi or if I use a powered USB hub. That strikes me as a USB driver issue, but I'm willing to be corrected.

daviewales
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Re: Second impressions

Tue Jun 05, 2012 5:27 am

I had problems until I switched to an old apple usb keyboard (from one of the original iMacs!!!) and updated my kernel using Hexxeh's tool. I'm using a 2 amp iPad charger.

http://hexxeh.net/?p=328117855

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