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by r4049zt
Sun Aug 19, 2012 8:12 pm
Forum: Beginners
Topic: HTML5 and Flash
Replies: 14
Views: 5151

Re: HTML5 and Flash

Flash was devised as a cunning plan to get people to throw away otherwise good Windows95 PC's. So try to ignore flash sites and don't expect the makers of it to provide for your fancy-media wish on anything less than the most expensive hardware. If you need Flash then you might as well buy a Windows...
by r4049zt
Sun Aug 19, 2012 8:02 pm
Forum: Beginners
Topic: Australian power supply
Replies: 11
Views: 8931

Re: Australian power supply

I you really have loads of old power supplies lying around, Find one which says that it can do 4.7,4.8,4.9 or 5.0 V (any) and at least 800mA, preferably more. Snip the end off it, strip cable ends, and with a multimeter find which one is +5 and which is 0 Volts. Solder the 0 Volts line to the end ne...
by r4049zt
Sun Aug 19, 2012 7:49 pm
Forum: Beginners
Topic: Internet issue
Replies: 2
Views: 484

Re: Internet issue

Mine works, so I'll answer some questions but cannot promise to fix yours. All that I did was to plug in an ethernet cable and switch the modem on before powering up the rPi. It was a known good modem, from which a PC has previously connected to the internet. I noticed that my rPi does not seem to n...
by r4049zt
Sun Aug 19, 2012 7:38 pm
Forum: Beginners
Topic: My TV only has SCART
Replies: 3
Views: 6763

Re: My TV only has SCART

rPi outputs SVID and HDMI. The going rate for a nice 1920x1080 pixel full HD monitor of about 24 inches with HDMI is upwards of $150. If that is not a lot more than a something-to-HDMI or HDMI-to-something converter box then a monitor is the better buy. If you are recycling old tv screens off the ne...
by r4049zt
Sun Aug 19, 2012 7:30 pm
Forum: Other projects
Topic: Can you guys help me get this dvd LCD to work with my Pi?
Replies: 2
Views: 893

Re: Can you guys help me get this dvd LCD to work with my Pi

If your display screen has a hdmi input then you might get it to work. Mine, from a reputable manufacturer, needed a button labelled 'enter' next to the on switch to be pressed a couple of times. Who could have guessed? If your media device is a closed box with neither HDMI nor SVID inputs then try ...
by r4049zt
Sun Aug 19, 2012 7:21 pm
Forum: Beginners
Topic: USB PS/2 adaptor - likely to work?
Replies: 9
Views: 7115

Re: USB PS/2 adaptor - likely to work?

Glad that yours works. Mine works, and I have now confirmed that with a second old PS2 keyboard and PS2 mouse. Shoving a usb stick into the 2nd usb socket stopped it though, so I'm not reporting complete success. (After a power-off and reboot) I got PS2 keyboard and PS2 mouse off the top of the two ...
by r4049zt
Sun Aug 19, 2012 7:08 pm
Forum: General programming discussion
Topic: Potentially useful things to program
Replies: 8
Views: 3699

Re: Potentially useful things to program

If you are looking into nice coding, "Numerical Recipes in C" is an old classic textbook with example code for the sort of tasks which got mentioned here. How about computing a 256 colour image according to the number of iterations before leaving the boundary radius of 2 around the Mandlebrot set? T...
by r4049zt
Sun Aug 19, 2012 7:01 pm
Forum: Beginners
Topic: backing up
Replies: 21
Views: 4703

Re: backing up

I'd recommend physically pulling out the sd card which you want to back up, and plugging it into a card reader usb device at your pc or laptop. That makes sure that it is unmounted at the time of using dd. I've only done that with dd on a linux PC so cannot comment on Windows. The result of dd will ...
by r4049zt
Sun Aug 19, 2012 6:53 pm
Forum: Beginners
Topic: unable to understand "cp"
Replies: 10
Views: 3323

Re: unable to understand "cp"

Not sure about this, but if you try again what you had tried, with a * at the end, does it copy?
* is supposed to mean "anything"
by r4049zt
Sun Aug 19, 2012 6:50 pm
Forum: Beginners
Topic: Mounting Self Powered USB Drive
Replies: 4
Views: 1460

Re: Mounting Self Powered USB Drive

I suspect that your 5.5V could conflict with the rPi end using 3.3

Also, I've not had complete success with all usb devices. rPi thought that the sd card from my camera in a usb card reader was a 'read only file system' and did not mount it. My linux pc had no trouble at all seeing that sd card.
by r4049zt
Sun Aug 19, 2012 6:42 pm
Forum: Advanced users
Topic: usb hub
Replies: 7
Views: 2169

Re: usb hub

Can't answer the specific question about a specific usb hub. I'm using a 1amp 5V rated approved rpi power supply from rs. That works for sure. I've been able to demo the rPi from 5V four NiCAD batteries connected at D17. In another test, another four NiCAD batteries providing a separate 5V for exter...
by r4049zt
Sat Aug 04, 2012 3:17 pm
Forum: Beginners
Topic: Best Browser on the Pii
Replies: 7
Views: 9965

Re: Best Browser on the Pii

I've not tried chromium on the pi yet but it was quick and smart on my ubuntu linux pc. I noticed that my own website looked fine on the default browser on the pi, but that many other websites did not. That suggests bad practice not complying to standards on much of the www. Is it too much to ask re...
by r4049zt
Sat Aug 04, 2012 2:56 pm
Forum: Beginners
Topic: Solar Powered Pi's
Replies: 22
Views: 12461

Re: Solar Powered Pi's

Whilst you could find a fan to make 8W while the car is moving, for example 0.7A at 12V, that is intermittent and small compared to the alternator. A regulated any-to-5V buck converter off the cigarette socket might be a less intermittent supply and its extra load on the alternator would be less tha...
by r4049zt
Sat Aug 04, 2012 10:49 am
Forum: Beginners
Topic: Solar Powered Pi's
Replies: 22
Views: 12461

Re: Solar Powered Pi's

Looking at differences in consumption figures between when we're away from home (couple of months per year) and at home, it looks very much as if our fridge is nearly half of our electricity usage. (Although we don't use a lot). The next one we buy will be super-efficient :lol: Over its lifetime, it...
by r4049zt
Fri Aug 03, 2012 3:43 pm
Forum: General programming discussion
Topic: Why not program on x86 desktop?
Replies: 60
Views: 14250

Re: Why not program on x86 desktop?

I noticed in the early 1990's that the x86 desktop hid too much from view to really dabble and find out how it works. Tasks which worked on a beeb with a few kB of RAM now took up a few MB. Twenty years on it still takes a minute to boot, still churns though unexplained checks at inconvenient times,...
by r4049zt
Fri Aug 03, 2012 2:44 pm
Forum: General discussion
Topic: Raspberry Pi Cooling system? :D
Replies: 77
Views: 18183

Re: Raspberry Pi Cooling system? :D

110 mA at 5V should be ok with a normal rPi ac power supply unit. As the fan does not need to be regulated as carefully as the 4.8 to 5.0 Volts supplying the pi, you could dabble with independent other power supplies for it. An independent other power supply to the + of a large transistor or FET and...
by r4049zt
Fri Aug 03, 2012 2:00 pm
Forum: Beginners
Topic: Solar Powered Pi's
Replies: 22
Views: 12461

Re: Solar Powered Pi's

I'd thought about all this a while back. Costings for a 220 Watt solar panel at 60p/Watt are way too high for the p/kWh used by a small computer alone, so that's why I added an (optional) grid tie inverter to a setup with oversized silicon solar panels, to make use of surplus solar power. It is stil...
by r4049zt
Thu Aug 02, 2012 7:04 pm
Forum: Beginners
Topic: Solar Powered Pi's
Replies: 22
Views: 12461

Re: Solar Powered Pi's

This post is writtn from a solar powered raspberry pi. Four NiCad batteries were charged to 5.4 Volts from solar power and tried. That did not work and neither did 5.3 Volts. This try with 5.25V at the battery got 4.98V at D17 and worked. Both keyboard and mouse coninued to work as battery voltage f...
by r4049zt
Thu Aug 02, 2012 6:55 pm
Forum: Beginners
Topic: Keyboard/Mouse in Wheezy
Replies: 3
Views: 956

Re: Keyboard/Mouse in Wheezy

I've been dabbling with power supply and found out a check which might help. Turn you board over and prod component D17 with a multimeter. Mine shows 4.9 Volts with an approved 5V 1A supply. It loses keyboard or mouse if outside of the range 4.4 to 5.0 Volts at D17. It still boots text-only up to at...
by r4049zt
Thu Aug 02, 2012 6:45 pm
Forum: Beginners
Topic: What's the best PSU?
Replies: 14
Views: 4821

Re: What's the best PSU?

First, correcting an error in my previous post. I meant eight 6V torch lightbulbs, but wrote something else by mistake. Second, I can now advise that supply of 4.9 to 5.25 Volts seems to work. This post was written from my raspberry pi, running on only four NiCad 2000 mAh batteries, charged from sol...
by r4049zt
Thu Aug 02, 2012 3:44 pm
Forum: Beginners
Topic: What's the best PSU?
Replies: 14
Views: 4821

Re: What's the best PSU?

Others have made valid recommendations but nobody has talked about testing. Your 700mA rating sounds a bit borderline. For example, one 64GB usb memory stick draws an extra 200mA, so your rig might work fine until you plug one of those in. If you can find 600mA worth of 6 volt torch batteries (eight...
by r4049zt
Thu Aug 02, 2012 3:19 pm
Forum: Beginners
Topic: Solar Powered Pi's
Replies: 22
Views: 12461

Re: Solar Powered Pi's

The 60 Watt panels on ebay look a bit pricey. Better to get a 180 to 240 Watt rated panel at a similar price. I use two KD235-2Pb connected parallel into a pair of car batteries with a 20A pwm regulator from panel Vmp voltage of 25 to 30V to batteries at 23 to 27V and a 28 to 52 Volt rated 350 Watt ...
by r4049zt
Thu Aug 02, 2012 1:05 pm
Forum: Beginners
Topic: Low cost mouse
Replies: 4
Views: 927

Re: Low cost mouse

I use a really old scrap PS2 mouse and keyboard into a PS2+
PS2 to usb adapter cable. That leaves a free usb socket for other things and cost less than the cheapest new keyboard.
by r4049zt
Thu Aug 02, 2012 1:00 pm
Forum: Beginners
Topic: usb hub power ?
Replies: 20
Views: 4010

Re: usb hub power ?

I have not tested the upper of two usb sockets on the pi, but the lower got 3V not 5V when powered from the rPi board with a 5V 1A rated micro-usb power supply. Therefore I'd expect issues with trying to power an rPi from an external usb powered hub via the lower of its two usb sockets. I have a 7-w...
by r4049zt
Thu Aug 02, 2012 12:47 pm
Forum: Beginners
Topic: Solar Powered Pi's
Replies: 22
Views: 12461

Re: Solar Powered Pi's

I second the comments made in the first reply to this post. Don't buy products which are too small for 5V 1A rated. I have got my pi to boot off a block of four 2000mAh NiCAD rechargeables but those only delivered 4.7 Volts at D17 which is 0.2Volts below normal measured operating condition with an r...

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