Raspberry Pi questions

I’m thinking of taking the plunge and getting a Model B Raspberry Pi. The main reason for doing so is that RPCEmu on my Mac resolutely fails to network, and in any case it would be nice to muck about with real RISC OS hardware again. I’ve got a few queries, though:

- What’s currently the best way of getting RISC OS on to it? The Mac has an SD card reader, on to which I can presumably download NOOBS to get going, or alternatively I could buy the ROOL Pi card. Once that’s done, do I use PackMan to update the OS? Or best to use something like Piccolo’s SystemDisc to keep everything in line?

- Due to where the study is, I’m not likely to be able to run an ethernet cable to it. There’s a good wi-fi connection. Has anyone had any success in getting networking working with a wifi bridge or similar? Or can I get access to the internet via the Mac somehow (complete networking dunce here – any advice welcome)

- My old Dell monitor is still going strong and I don’t really want to upgrade it. Will I be able to get a display with an HDMI-VGA adaptor?

Any answers or general tips much appreciated.

Well, I recently decided to go for a Pi myself (a model A however). The easiest way by far is of course joining RComp’s support scheme for the Pi and that’s what I did. Received my pre-loaded SD card, stuck it in my Pi and that’s all there is. Plug and Play really. While it’s not the cheapest way (and you could do everything yourself if you invest some time playing around with dd and !SystemDisk from piccolosystems¹) they do include a class 10 SD card plus some software. The entire card is usable of course (16GB).
Even setting up the network was just a matter of connecting my Lindy Ethernet-USB adapter. In your case you’ll need a WiFi bridge, no personal experience with those myself but can’t be rocket science.
You could in theory run a VNC server on your MAC but that doesn’t sound too practical.

VGA, really? The adapter would probably² cost more than a mid-range digital monitor. Even a HDMI TV set
would do. Rcomp provide a range of suitable MDFs btw should you consider going down that route.

Rcomp usually release OS upgrades via website download. Login and download a zip file, then use an installer that comes with everything. This too works very well, bit old school though.

¹ ISTR Raik had a suitable image for download
² Or not, see Rick’s post

What’s currently the best way of getting RISC OS on to it?

Download an SD image from RaspberryPi.org to get something running, but note that the image is really old. It’ll get you going, but afterwards you will want to download the most recent firmware from GitHub and then the BCM ROM from here to get you to something more recent. However, get yourself going first…

[alternatively, the ROOL Pi card will be an all-ready-to-roll option]

Has anyone had any success in getting networking working with a wifi bridge or similar?

There is a gadget (Lindy?) that talks WiFi and has an ethernet plug hanging off of it. What you do is plug this thing into the Pi’s ethernet, set it up, and bob’s your uncle.
I don’t have experience with this. I really ought to get one of these things myself…

Will I be able to get a display with an HDMI-VGA adaptor?

I don’t know what Patric is imagining with saying the adaptor would cost more than a mid-range monitor. Mine came from eBay and it cost €2,99+€10,99 postage, and a further €2,38+€1,16 postage for an adaptor to make the plugs and sockets fit. I’d love to hear where I can get a reasonable HD monitor for <€20! ;-)
→ Device is http://cgi.ebay.fr/ws/eBayISAPI.dll?ViewItem&item=271221914443
→ Adaptor is http://www.ebay.fr/itm/Gold-Plated-HDMI-Male-to-Mini-HDMI-Female-Connector-HD-TV-Converter-Adaptor-HDTV-/320822991617

Holy <expletive>, it’s fifty euros now! Well, the beauty of eBay is that there is always another vendor. This looks alright and it is under a tenner (€) with free postage → http://www.ebay.fr/itm/HDMI-Male-to-VGA-Female-Adaptor-Cable-Audio-Cable-White-HDTV-/370937522356 – judging by the photo it might be the same sort of HDMI connector as on the Pi so the adaptor won’t be necessary. ;-)

A piece of advice I would give you is if you have any skill at all with a soldering iron, to mod your adaptor to run off a USB cable. A lot of people will tell you that it is okay to run the adaptor off the Pi’s HDMI, however the HDMI is only rated to competently output 50mA. The adaptors will suck more than that. Mine, data I’ve found online suggests 100-200mA depending on resolution. Better safe than sorry.
The process isn’t hard. Open the thing up, disconnect and isolate the +5V supply from the HDMI plug. Then patch in a USB cable. The whole process is described here → http://www.heyrick.co.uk/blog/index.php?diary=20130729

Should you bother? Well, plug your HDMI adaptor into the Pi. There is a little flat three pin diode to the left of the HDMI socket (with socket closest to you). It is marked “D1”. Touch it after 30 seconds, then 60, then 120. If it is hot, as in real hot, power down before you damage the diode. If it is fairly hot, you are running it a bit hard. If it is just warm, that’s not so bad.

The final step is a lovely feature of the Pi that is sadly missing from the Beagle. You can configure the HDMI output from the CONFIG.TXT file so you can get something on the screen right from the get-go. I always have a nice solid output from the Pi. The Beagle, I’m still stuck with half the time seeing nothing whatsoever, must be some timing issue or the like.

Anyway, my monitor is a flat panel 1280×1024 so I set up the following:

hdmi_drive=2
hdmi_group=2
hdmi_mode=36
disable_overscan=1

The HDMI drive sets up how sound will be handled. My adaptor has an audio output, so I can route audio through the HDMI.
The HDMI group tells the GPU to revert to “DMT”, the old style video display modes (instead of HD TV resolutions).
The HDMI mode “36” tells the GPU that my monitor is 1280×1024 clocking a 75Hz refresh.
There is a full list here → http://elinux.org/RPiconfig (DMT is the second long list of modes). Pick whatever fits your monitor’s native resolution.
The disable overscan makes it all fit into the visible part of the screen. ;-)

Once you have RISC OS running, you’ll need to bumble around in the configuration to pick a screen definition that sort of fits. Don’t worry about the monitor “type”, so long as your resolutions all match up. There was a discussion about this here → https://www.riscosopen.org/forum/forums/5/topics/1982

Then – turn on the monitor, then power up the adaptor, and finally power up the Pi. It looks good, and having never used a Pi on anything larger than 800×600 in my life until now, it seems a bit ridiculous to have 1280×1024 to play in! Example of this in action in the top picture here → http://www.heyrick.co.uk/blog/index.php?diary=20131105

By the way:

Even a HDMI TV set would do.

It is my understanding that some HDMI TV sets have a lot of image processing/correction technology inside to overcome shortcomings in the system and make television images (often moving) look better. The flip side is that they apparently make quite a mess of computer signals for which you want no processing. If you use a TV, make sure you can disable the smarts and get the TV to act as a dumb display device and not attempt to “improve” the image.
I cannot speak from experience, my monitor cost €3 from a boot sale. An HD TV is out of my price range, and a bit pointless as nothing here other than the Beagle/Pi speak HDMI. Even my satellite TV is SD! [not that I watch it much anymore – horriblesubs is my bookmark, or NHK World on the iPad]

RISC OS is loads of fun, and with such an inexpensive yet capable device as the Pi, it is almost criminally easy to get it all going.

Here’s another tip – download the NOOBS package onto another (brand new) SD card. No big images, just unzip the files and dump ‘em on the card. Start the Pi with that and then ’install’ RaspBMC. Want to watch videos on the same system? Just switch SD cards and off you go. HD is no problem. Your adaptor may or may not cope with HD1080 (mine didn’t), but 720 will be no problem for the Pi. More info here → http://www.heyrick.co.uk/blog/index.php?diary=20130815

What’s currently the best way of getting RISC OS on to it [Raspberry Pi]?

Buy a ‘RISCOSPi’ card from ROOL and a ‘NutPi’ card which has lots of software.

Alternatively get a fast class 10 SD card and download RC11 (not NOOBS which currently has an out-of-date version of RISC OS on it) from the Pi Foundation site and put it on using Win32DiskImager.

Both of the above give you 2Gbytes of storage for RISC OS.

Alternatively use Piccolo Systems ‘SystemDisc’ to dual-partition format a nice large and fast SD card – now you have to get the firmware and RISC OS boot files onto it yourself.

Has anyone had any success in getting networking working with a wifi bridge or similar?

Yes. See here

Will I be able to get a display with an HDMI-VGA adaptor?

Probably not. Certainly not easily.

I don’t know what Patric is imagining with saying the adaptor would cost more than a mid-range monitor. Mine came from eBay and it cost €2,99+€10,99 postage, and a further €2,38+€1,16 postage for an adaptor to make the plugs and sockets fit. I’d love to hear where I can get a reasonable HD monitor for <€20! ;-)

Ok, that’s a surprise! Last time I looked they all seemed to cost EUR 100 to 150 so I quickly dismissed the idea. Probably didn’t look hard enough, not that it matters as my Pi is now married to a rather nice Lapdock :)

(The Beagle OTOH is connected to a FullHD TV in order to run a 1920×1080 resolution @45Hz. It does have a “PC monitor” setting however and also works fine as a VGA monitor for my Linux box.)

Try a look for HDMI>VGA adapters at Amazon. I bought one not long ago for around £10.
If you get one with Audio skt on the side you can feed the sound into a TV via the
aux input ( if it has one)

I heartily endorse Rik’s advice about modifying these vga adapters to get their
5volt power directly from a powered usb hub rather than from the Pi.

The wire in the adapter lead is very thin and can cause volts drop that sometimes
makes the video drop out.

Chris:

and put it on using Win32DiskImager.

He’ll need something that does that for a Mac. Just looked at the Win32DiskImager site and it looks like it is Windows only (clue in the name? ;-) ).
I was somewhat amused by the poor ratings for those who had huge USB drives of years of super-important work that “somehow” got trashed by the software. It’s a USB drive – is it so hard to disconnect before you do an action that is data-destructive to avert the risk of mucking it up and formatting the wrong thing?

Probably not. Certainly not easily.

Have you tried? The hardship, for me, was getting the configurations sorted. The HDMI adaptor “just worked”, but it is rather finickety about its input – and it has no sort of on-screen display to say “naff input” to guide you to what it is unhappy with. I could use that with the Beagle, but…

Anyway, wasn’t too difficult – but then I’d move a mountain if it freed me from using composite video with a USB digitiser.

Patric:

Last time I looked they all seemed to cost EUR 100 to 150 so I quickly dismissed the idea.

Prices are all over the place on eBay. I really don’t understand why the thing I bought for three euros is now fifty. That’s weird. However a useful technique is to look for vendors outside of those listing in your own country (link at the bottom). Okay, it might come from Hong Kong via Singapore Post and take a while, but when the all-in price is cheaper than a local wants to charge for postage alone, it might be a better option?

as my Pi is married to a rather nice Lapdock :)

Well, that’s the “awesome-and-stuff” option.

The Beagle OTOH is connected to a FullHD TV in order to run a 1920×1080 resolution @45Hz

? Your Beagle runs HullHD? The OMAP37xx datasheet (p1552) describes video capabilities as:

• SXGA+ - 1400 x 1050 direct drive of LCD with minimal blanking at 50 fps (pixel clock = 75
MHz)
• HD 720p - 1280 x 720 at 60 fps (pixel clock = 74.25 MHz)
• 256 x 24-bit entries palette in red, green, and blue (RGB)
• Programmable pixel rate up to 75 MHz

Given that 1400×1050 runs at 75MHz and the maximum pixel rate is 75MHz, I figured that 1400×1050 was about the most you’d be able to push out of an xM at those sorts of framerates (note that it says “minimal blanking” because otherwise it would be beyond the capabilities of the video hardware).
For 1920×1080, it would surely require a severe drop in framerate (something in the order of 24Hz?).
A vague rule of thumb calculation on 1920×1080@45 would seem to imply a pixel clock of around 95MHz. How’d you manage that? Are you using less than 24bpp?

Your Beagle runs HullHD?

I think there are a lot of BB users running 1920×1080 at around 40Hz or so. I certainly am, and R-Comp supply suitable MDFs with their ARMini machines.

For 1920×1080, it would surely require a severe drop in framerate (something in the order of 24Hz?).
A vague rule of thumb calculation on 1920×1080@45 would seem to imply a pixel clock of around 95MHz. How’d you manage that? Are you using less than 24bpp?

You’re probably right. It’s been several months since I last had access to my BB (which is also the reason why I desperately wanted something a bit more mobile than a clunky desktop). I posted elsewhere that I actually used 25-38Hz so you’re spot on.

The RaspberryPi isn’t as limited, no need for any special monitors there!

Thanks to all for replies. Looks like the Pi card from ROOL is the easiest way to get started, and this seems like the solution for networking.

However, the monitor thing is a bit trickier. Thanks to Rick for highlighting the issue with power supply. I’m not confident about performing the fix outlines on Rick’s blog. Equally, upgrading my otherwise perfectly fine monitor would negate the chief attraction of the Pi – a cheap and simple way to get a real RISC OS computer again. I’ll have to give it some thought.

I’d consider getting a monitor with a DVI connector, it’s quite likely you’ll be able to get one for free somewhere. Then all you need is a HDMI<→DVI cable and you’re off.

…and this seems like the solution for networking.

I might be mistaken but if this is what I think it is you’re out of luck.
Wouldn’t let the monitor issue stop me from getting a Pi btw. I originally bought a s/h DVI-D monitor for the Beagle for 15 quid at cash converters. And even if you live somewhere in rural France where that isn’t an option you could still buy one of these converters Rick wrote about!

Looks like the Pi card from ROOL is the easiest way to get started,

That is true but getting the raw download of rc11 onto a card using the Mac is quite easy too – this does not have to be either or, one can have any number of SD cards to fiddle around with in getting used to the various ways of doing things, just keep a known good SD card safe, if an installation does go wrong it is only a card, reformat it and try again. Getting to grips with the SD card is all part of the fun.

I currently run a NOOBS built card with the old duff RISC OS completely replaced by the most recent ROOL ROM and !Boot, and later firmware. The only thing that needs to be left strictly alone is the Fat partition, !Boot.Loader, which means just the partition itself, its contents can be updated.

I keep the the SD card as simple as possible, most of my stuff is on an SSD.

and this seems like the solution for networking

There are no RISC OS drivers for a WiFi dongle. I just tried the one that came with my Maplin kit – nothing doing, it has to be wired. My incoming internet is not in the same room as the computers, the current less than cheap system is an Airport Extreme connected to the fibre modem and a Time Capsule in “extend a wireless network” mode in the computer room. Plan B is the not so cheap either Devolo mains plug things.

As for monitors the Pi should HDMI into any modern TV.

The Pi is good, RPCEmu on the iMac would be good but though mine does network it does stiff inconveniently. VRPC on the iMac can also stiff itself and isn’t RISC OS 5.

There are no RISC OS drivers for a WiFi dongle.

Hmm. This is maybe not the right option, then. A network-less RPi doesn’t offer much to me over my current RPCEmu, which is pretty stable here. Going to the trouble and expense of getting a new monitor/network setup rather negates the point of a cheap and cheerful RISC OS box.

The perfect solution for me, TBH, would be continued development of the Mac RPCEmu, but this seems to have stalled recently.

Going to the trouble and expense of getting a new monitor/network setup rather negates the point of a cheap and cheerful RISC OS box.

Perhaps this? A mite under twenty euros for an adaptor to talk WiFi from ethernet: http://cgi.ebay.fr/ws/eBayISAPI.dll?ViewItem&item=300881762921

Configur an old router as a bridge. […] though it works

…sometimes. Depending upon your primary router. For example, with the Livebox (v2/Sagem), I have had no success in using an AP “backwards” (in other words, using the WiFi to receive and connect to a second section of LAN). It was explained to me that the main AP (the Livebox) must understand bridge mode (one WiFi device supports numerous IP addresses), as opposed to the normal client mode (one WiFi device = one IP address).

If yu plan on using it at home I would recomend using a wired connection.

I’m pretty damn wary of that given what happened when lightning cooked my Livebox. As the phones (VoIP so not a direct connect) and stuff attached to USB all got flash-fried, I would imagine it’d be a sorry tale for anything hooked to ethernet as well. http://www.heyrick.co.uk/blog/index.php?diary=20120905

Plus, with the layout of the house, and the mess it would make to attach ethernet cables to stuff, this is a WiFi-only setup. It’s the easiest way.

and it is prety unlikely that you will get much through the router and out the other side. You are at risk of frying the router either way.

Enough to fry the ether port of an Iyonix, side track through the mouse cable left my arm numb for about 15 minutes.

Router = interesting box with RJ45 ports and a rattling set of innards. PVR downstairs – PSU=toast.

WiFi is both a lot more dificult and a lot more expencive

Most stuff comes with WiFi these days. Both netbooks, three Android phones, and an iPad. Of my assorted equipment, about half of it has no provision for wired networking (heck, it’s hard enough getting the iPad to talk to anything else as it is!).

As to the concern of Lightning damage, going WiFi will not negate this,

Yeah, it will. A lot. The devices (some running off battery) will not be directly connected. There will be an air gap of several metres.

and it is prety unlikely that you will get much through the router and out the other side.

Whuh? “pretty unlikely”? You think a tiny circuit board is going to absorb a near-direct lightning strike and nothing dangerous will come out the other side? Let’s remind you that if the spark traverses the kilometres between cloud and ground, the few square inches of a circuit board will not be much of an issue. Or, to put it another way, if you have suffered lightning damage, you probably weren’t a direct hit.

Lightning hit the phone line and punched its way into the Livebox. I know the telephone line was the entry point due to the level of damage to the ADSL filter, and the fact that the Livebox and its associated bits were the only damaged pieces of equipment. I will embed the photo of the filter directly here:

[I couldn’t get a photo of the inside of the Livebox, they wouldn’t accept it back if
the tamper seals had been broken, suffice to say that I looked with a torch and
most of the circuit board looked the same…]

Result?

• The Livebox was killed. So much that things inside exploded and rattled around inside the case.
• This went out of the low voltage side and blew up the power pack. The power pack’s sides were bulging, and stank of burnt circuit board.
• Connected into the Livebox’s USB port was the transmitter module for a Livephone. One of the snap-on covers was half way across the room. The circuit board? Wasted.
• Connected into the VoIP phone port was a normal bog-standard phone. Which no longer works.
• Connected also to the VoIP phone port was a DECT radio phone. The phone was dead, the charger unit was blackened inside, and the power brick was ruined – the capacitors blew up but the casing held.
• Connected also to the VoIP phone port was a rotary dial phone that I am fixing up. It was unharmed. ;-)

So, given the above, I rather suspect anything connected to the ethernet ports would also have been destroyed.

Also, given the above, I would strongly recommend people to unplug stuff in the presence of a thunderstorm.

You are at risk of frying the router either way.

Could care less about the ADSL router – it is on rental, I just contact Orange and request a replacement…

Remember a good gigabit wrouter with 8 physical ports is about $10USD

Are you referring to the ADSL box? If this is the case, kindly point me to a box that has built-in SIP VoIP (SIP 8/51). I will remind you that our phone line is digital. We do not have an analogue phone (it all runs through the router).
I bought a spare crappy old first-release Livebox from a boot sale to use if the proper Livebox is out of service (but it is old encryption and slow as molasses in January), and I also have a WAG200G router set up for use in an emergency (but no phone port there), primarily because the extended functions of the OpenWAG firmware allow me to customise the ADSL behaviour for long noisy lines, so it can “try harder” than the Livebox ever could.

and CAT6 is about

…and CAT6 is unsuited for running through a loft with mice and cats and pine martens and badgers and stoats and phantoms and things I can’t even find in a book (the electric cables are either armoured or encased in solid metal piping); and it doesn’t easily nail into solid stone walls (plus having that stuff around really buggers up the aesthetic).

Please just accept, people, that some of us prefer to use WiFi.

WiFi is possible with a RISC OS Pi, but it has to be through an access point. Using a Model B and one of these,

works well and is easy to set up on a PC. They are available from many suppliers and are even a couple of pounds cheaper than when I bought mine.

You can do the same with a Model A and a Lindy USB-Ethernet adaptor. I do not know of another such adaptor that works out of the box with RISC OS, but maybe there will be, after progress in another topic here.