First post from my Pi Zero!

This didn’t really fit anywhere. A couple of days ago I received the Orange Pi PC I had purchased and an interesting multifunction device.
The Orange Pi was so I could free up the Zero which was on NAS duty so it could be a dedicated RISC OS machine.
The multifunction device was the second part of the puzzle. It’s about the size of a Mars bar I guess, white, and has three USB ports, an ethernet port, a barrel connector for power input and a Micro USB OTG connector for the host device which is perfect for a Zero.
Right now I’m using my Zero with it plugged in, providing the ports for keyboard and mouse, and for the ethernet which “just works”.
This seems like the neatest way to make a Zero into a RISC OS machine. It definitely works better like this than as a NAS.

Just thought I’d say there is an easy way to use a Zero and have ethernet on the cheap. I can dig up the details if anyone wants them.
It’s also a bit of a test to check this works.

I would be very interested in the multifunction device details, please.

Sure. I just learned that it is something I can’t easily do from within RISC OS for a few reasons.
I did manage to get the Aliexpress link to the one I bought. However NetSurf doesn’t seem to be able to cope with it.

http://s.aliexpress.com/Y7FRNvuY
I recall from “lsusb” It uses an AX88772A ethernet adapter. Can’t remember the USB hub type though sorry.
If the link doesn’t work, let me know. I only have the Zero with RISC OS accessible right now. There’s probably ten thousand sellers with the same item on the web.

Sorry about the weird post. It was late, and I was tired but very happy. I’d been wanting to test the device however I didn’t have the time until then.

I just remembered something. When i quit from Configure after pointlessly fiddling with the network interface, RISC OS died. The screen went black except for a dialog that looked to be in a different resolution and possibly lower colour depth, saying something like “cannot relocate memory” with a cancel button I couldn’t click because the keyboard and mouse stopped working. No problems after a power cycle.
Strangely the Zero actually remembered the correct screen mode instead of needing to change it with WimpMode. Did anyone end up working out why the Zero doesn’t set screen modes correctly on boot?

The error ‘cannot relocate memory’ occurs on my Pi: the combination of a CJE real time clock card and the use of my utility ScrnHelp makes this happen every time you select ‘Shutdown’.

Hmm. I have a DS3231 RTC connected to I2c, although I’ve done nothing whatsoever to talk to it in RISC OS. I set up the overlay in Linux which worked fine.

Having a dedicated machine is nice. Although slower, I was doing builds using an NFS share so it was only thrashing the NAS’ spinner instead of the Pi’s USB stick or SD card. Honestly I did what I always do with the Pi with RISC OS. I used it until it made me sad. This time around I wasted way too long just trying to make the simplest possible library compile and link. Just a single function. It didn’t work.

@ Tristan M.

Thanks for the link to the multifunction device.

One on order.

No worries. I’m still happy with mine. The day before yesterday I was using my zero, while listening to music on it via NFS share. That was nice. It still does a better job than the pi 3 running linux.

Speaking of which, I only just discovered I accidentally left the Pi 3 clock speed settings in the pi zero copy of RISC OS. Whoops!

Last night I just wanted to listen to some music before bed. No big deal. Right? It turned into a headache. First I tried to use the Pi 3 running Raspbian. My music is on the Orange Pi running headless with some kind of Ubuntu on it.
After tweaking a script so I could mount it easily and dumping what I wanted into Audacious the program froze, things went a bit peculiar and I had to reboot it.

With RISC OS it was just a few clicks with Sunfish, and dragging what I wanted into DigitalCD. Then remembering that I needed to run something to shift the audio pins on the Zero. But it was all good and still took way, way less time than in Linux.

My Zero can play back music perfectly in RISC OS via the network and do other light foreground duties while the Pi 3 with Raspbian struggles to do it when absolutely nothing else is going on.
RISC OS is almost my go-to solution for audio playback except I can’t figure out how to get playback of ogg vorbis and FLAC to work.

At the risk of hijacking the thread, do you happen to have tried playing AAC? DigitalCD gives random noise if I set the type to AMPEG. If I use MPEG then MPlayer will grab it and successfully play the sound, but it treats the file as video and covers the entire screen with the album cover art. Does anyone know whether any other apps can handle this a bit better?

I don’t know how you managed to get it to even try playing AAC. I just tried and it wouldn’t. I fixed ogg and FLAC at least. I went through and double checked the mimetypes file in DigitalCD’s modules.zip against the system’s mime types. It was missing a bit and I had to edit a few entries. I just successfully listened to a FLAC file. I know I have some albums in ogg but I could only find the one that doesn’t play properly on 99% of players and hardware. It played like most other things can play it. All static-y and weird. Probably works fine with non broken files.
All that was in DigitalCD by the way.

More waffle. I ordered a couple of those USB power cables with the switch on them from Aliexpress. They arrived today. I tried one on the Pi 3.

Moral of the story: Don’t buy one for a Pi 3.
It was so bad that the undervolt warning was constantly lit and there was red horizontal lines on the screen from either HDMI feed corruption or the RAM getting a little scrambled. I still haven’t found one that works well enough to enable me to take off the capacitor I have attached between 5v and gnd on the GPIO connector.

It was so bad that the undervolt warning was constantly lit

Back feeding power from the hub (assuming it will supply 500mA) to the USB ports will fix probably this….you’ll probably find the power switch will switch it on, but not off though.

USB power cables with the switch

Warning: All the USB power cables with the switch I’ve seen, do not pass D+ and D- through, there are a number on ebay that make no mention of if the USB lines are connected or not. All those I questioned replied: Not connected. So they are fine¹ if all you are doing is powering a device through them but no use if you wish to also use USB.
[]Providing of course that they are of good quality and don’t give a voltage drop like Tristan found.

I suspect that not many people have read the part of the USB specifications that cover the cable, and assume that what goes in to one end of the cable comes out the other end. I have read it. As a result, I believe that most “USB” cables on sale do not conform to the USB specification.

If the cable is thin and flexible, it doesn’t conform – there isn’t enough copper in it.

The problem is exaggerated when the cable is being used to feed a computer, e.g. a Raspberry Pi, that consumes more than the 500 mA that USB originally intended. The higher resistance, multiplied by the higher current, result in a much increased voltage drop in the cable.

Yes exactly! It is very hard to find a USB cable that isn’t literally substandard. The Pi 3 also puts a high demand on micro USB cables which goes above and beyond the standard.
I had hoped that the cables I bought, while cheap would have consisted of wire of a thick enough gauge that it would not cause the voltage drop issue under load that I keep having with the Pi 3.

I have said it many times. I believe using a Micro USB connector as a power connector, especially on the Pi 3 is a bad idea. The only reason I haven’t just connected straight to the GPIO +5v and gnd is I want to keep the polyfuse protection.
On this subject, I am 100% certain it is the USB cable at fault. Every cable I try has a different degree of the issue. The power supply I am using is 5 Amp. I have also upped the voltage of it using it’s calibration pot. It is connected via a cable with either 1.2 or 1.4mm cores (I forget) to a 7 port USB hub which I have modified, via a female and male inline barrel connector with screw clamps.
I use the USB hub because it has switches for every port. When I got it I added a power diode explicitly to prevent power backfeed if I chose to actually use it for USB. I also did a better job of soldering all the connections than the factory, soldered the shells of the USB connectors to earth instead of just contact, added electrolytic caps for every port where caps had been deleted at some point, and added the barrel connector via a short flylead of the same type I used for the rest of the cable.
Nothing else has any issue running off it.
The Orange Pi has a special lead I made though. It uses the connector and lead from a broken PSP charger, and the male USB-A connector from gasp! a broken Micro USB cable. It can draw a heavy current too.
The undervolt condition on the Pi 3 is not influenced by the other things on the hub, with one exception. If I have the Pi 3, Orange Pi, Pi Zero, USB sound device, and USB powered hard drive hanging off the hub at once it gets a tiny bit touchier under load. Imagine that!

I can’t even use the Micro USB cable from a proper charger supplied with a tablet or phone, because the Micro USB connector has failed on most of those and ones that can still do the job are in high demand.

Micro USB connectors are frail at best. The deep and thin design is really not great. If a cord or device is accidentally pulled the result is a side load that breaks the plug, the socket or both. At least USB mini was less over square and more prone just to come out than cause destruction.

I just noticed the other switched USB cable sitting on the desk. i didn’t even bother unravelling it. i tlooks like they used “proper” cable. Ie it has markings on it. Looks like it’s 300v rated. “2.0 2mm^2” Weird spacing. 0.2mm^2 though? The switch is rated for 2A@250v too. This is all very bothersome. I still suspect the thin cable for causing a voltage drop. Who cares about a few mV drop at mains voltage? Drop the voltage and up the current and things get unpleasant. I think I’ve ranted enough for one night.

I think I’ve ranted enough for one night.

I’m right there with you. I think originally the decision to use a mini USB socket was a blend of cost (they’re cheaper) was dummy proofing. You literally cannot bugger up a USB connection. You know it is going to be (more or less) 5V. You know the +ve and -ve are going to be correct.

However with a modern quad core Pi and four USB ports (each of which are supposed to offer up to 500mA!), trying to shove all of that through such a tiny connector seems ludicrous.

However, one of the problems is that there are very many rubbish power supplies out there. I have seen 5V supplies that float at twice that. How would a Pi like that the moment it is powered up? By using USB, they can omit power conditioning as the supply ought to be a reliable 5Vish.

That’s not to say that using micro USB isn’t a rather dumb idea now. The new Pi models ought to use a chunkier connector that can handle the sort of demands being made of it.

You literally cannot bugger up a USB connection. You know it is going to be (more or less) 5V. You know the +ve and -ve are going to be correct.

You know initially I thought you meant physically rather than the volt throughput.
If you had meant physically then I can tell you that it is in fact perfectly possible to insert a standard USB plug upside down in the socket.
Admittedly it takes an employee with an IQ close to their shoe size but the guys in the workshop have photo’s of the result.

If you had meant physically then I can tell you that it is in fact perfectly possible to insert a standard USB plug upside down in the socket.

Jeez. It must have taken a brute to do that. Or the user has a habit of inserting the plugs at an angle instead of straight in.

I’ve managed to absent mindedly plug USB devices into ethernet ports (a surprisingly good fit), but have never managed to insert any of the USB permutations in the wrong way up.

Admittedly it takes an employee with an IQ close to their shoe size

I believe the generic term for that is “management”.

but the guys in the workshop have photo’s of the result.

Immediate result? Probably not a lot. That little plastic flap is likely to break. The fun will come when the USB device is seen to not work so the user removes it and shoves it back into the socket again (either way, no longer matters). Then, with the plastic flap broken, you’ll probably get one of three things:
1. The USB power lines will droop and short against the metal casing of the plug, in which case your computer will disconnect the power to the socket if it is really clever; but more likely the computer will crap itself when it sees a direct short on the 5V line, and will either immediately shut itself off, or fail to do that and instead various important looking things will go “pop”.
2. The plastic lug inside the plug will mash all of the wires together. The controller may even be able to cope for the first few microseconds with one signal line shorted to 5V and one to 0V; however shortly after we’d arrive at a situation where something at 0V connects to something at 5V. GOTO #1
3. Both of the above.

:-)

But, no. I meant electrically.

Though, I note:

1. The USB spec actually permits the voltage to dip down a bit. I don’t have figures to have, but it is something like 5.1V maximum and 4.4V minimum. The minimum is less than I’d have expected it to be.

2. We shall not discuss the weird <expletive> being stuck in USB wiring nowadays. Isn’t one of the options for something like 20V? OMFG – if they need something like that, they ought to invent a new connector and not mess with what everybody understands.

The correct charger for the Asus Transformer series of tablet does some kind of magic with a USB connector to output a higher voltage through the charger’s USB socket. Something like 16v for the dock I think. Never looked closely at the USB end of it. Hopefully it has extra pins somehow or something.

USB connectors are designed to plug in easily. Third time every time. Recently at a store I saw a USB hub which allowed the USB connectors to be plugged in either way up. Witchcraft!

I forgot to say that another reason why the cables are so bad, including the switched ones I bought. AC vs DC. There is a larger voltage drop with DC because of the basic nature of how electrons flow through conductors. DC is inefficient. Larger wires are generally needed to help.

I do my own autoelectric work, which is way more than any sane person ever would. If anybody suggested I use some wirewrap wire for something because it’s only an amp or two I would probably tell them that I won’t in a less than polite manner. I can’t speak for anyone else but I have burned out my fair share of USB cables.
If anyone ever plugs something in and it seems to be misbehaving a little, feel the cable. It may be warm, or it could even be hot! Tiny little cables are subject to thermal runaway and more or less blow like a fuse.
Once a certain current threshold is hit, heat climbs, so resistance climbs, and round we go.
It’s one of the reasons voltage drop on a USB cable is such a worrying thing.

I haven’t had any available time to work on anything RO related recently. Everything else has kind of been getting on top of me. I did want to share one silly little thing that I worked out today that makes !PackMan less irritating to use. In the package configuration window the package icon is draggable to the desired target directory.
I know there’s a paths file in !PackMan, but for reasons I don’t understand it seems to ignore it at least partially now and puts everything in subdirectories of “Apps”. At least dragging the icon gets the package where I want it.

Also because of my limited time I’ll have to make a slight concession and use the PC for at least working out components of librogpio that I want to do. A proper IDE and multiple monitors go a long way. Apparently I set up Code::blocks to be able to do GCCSDK projects and forgot. Having to do all the setup each time I wanted to use !GCC is taking too much time. Especially when a TaskWindow crashes.
At least now I have a Pi B it opens up being able to test more configurations.

I did want to share one silly little thing that I worked out today that makes !PackMan less irritating to use. In the package configuration window the package icon is draggable to the desired target directory.

Drag and not drop (bottom half-ish)

@Vince you may appreciate this site

Does it actually do anything? All I see is a static image with a slightly incorrect quote from Aliens. Looking at the source, I see a small script (which won’t run unless I allow it) – but that just appears to be related to Google Analytics.

Anyway, while I don’t like that whole “drag and not drop” approach for the reasons given in that RISCOSitory post, I do understand why it can’t be proper drag and drop in PackMan; the thing to be installed hasn’t (or may not have) been downloaded yet.

However, ISTR that when this was discussed on usenet my suggestion (one of?) was to actually drop a pseudo app, appropriately named, that if run would inform the user the real thing is still to be fetched and installed.

To sound less negative, rather than it being described as drag and drop (leading me to call it not drop) it should be described simply as drag and release. Perhaps it is in the instructions/help/whatever. :)

Anyway… food time.

VinceH (quote from riscository):

Is it just me, or is there a slight flaw in that?

About as big a flaw as intending to shoot one’s self in the foot “to see if it hurts” (an action otherwise known as “Brexit”).