Raspberry Pi Forums

r4049zt

another possibility; nothing to do with your sd card some hdmi monitors don't turn on straight away. rpi boots with a blank screen if it got no ok from the hdmi switch on the screen first and make sure that it is set to look for hdmi. then power the rPi. That one caught me out just now; it works fin...

r4049zt

I think that there is some unexplained luck involved in getting it to work with nonstandard power supplies. In the couple of months since I posted from a solar powered pi, I have carried on using it but use something else for main or business-critical email. Try stuff, break things, and see what wor...

r4049zt

The big question is how large is your database? can it be split into chunks of <160MB? Your best bet might be to get a medium sized database into memory, so that most of the work is done between cpu and on-board memory. That avoids old power wasters and bottlenecks. If your data needs more than 160M...

r4049zt

Having got somewhere with an rPi running off a 5V buck pwm module supplied from a 12 to 20 Volt 36 cell solar panel, I can add a few comments. The bigger the solar panel the better. Without batteries, mine would work until the sun goes in. A 30 Watt rated 36 cell panel worked but I'll need battery b...

r4049zt

That would work. I've just been online and got as far as logging in to the forum from a raspberry pi powered only from a solar panel into a suitable buck pwm module to give a regulated 5V output. No mains and no batteries, which I think is a first. The same module could work off a car battery, but I...

r4049zt

I guess something using LM2576-5 would work then for the 7+V range (it is what is in my car adaptor). http://www.ti.com/lit/ds/symli.....lm2576.pdf However, would a Zener diode regulator work, or would the current draw be way too much? The circuit which you sketched could just about get it to boot,...

r4049zt

I got it to work, and write this post from an rPi on a non-accredited noname 800mA 5.1V ac-dc adapter. I made three changes and do not know which of these matter. Anyone able to comment? i) swapped my non-recommended PS2+PS2 to USB keyboard and mouse adapter for a more conventional USB keyboard and ...

r4049zt

More power supply testing news ==================== I had a go with a cheap imported 5V supply marked as 800mA, broadly speaking as discouraged here. It provided 5.05 to 5.15 Volts and kept up with the 0.3 to 0.4 Amps demand from my rPi in normal operation. Despite providing acceptable voltage and c...

r4049zt

At this point I must apologise to all vga lovers whose hardware is not well suited to raspberry pi. At the time of an early proposal to ARM to release one of their CPU designs for educational and general use (which became the rPi), it was brought up that each of the several different video standards...

r4049zt

One approach may be to enlist the help of bright 14+ year olds to propose, implement and write up such tasks as i) Chop up spare +5V and 0V lines in an older desktop PC, fit a suitable fuse, and solder on new power supply wires to all of the rPi boards on a benchtop. Report on import cost savings an...

r4049zt

I'll have to make a few presumptions in order to try to answer your query. If your rPi is plugged in with ordinary ethernet cable to a modem which you know to be on the internet, then the first command to test connection within your house is to ping them modem. For example, if your PC is usually 192...

r4049zt

I'm still online from power from the red (+5V) and balck (0V) lines of a nearby PC. My rPi has been drawing 0.3 to 0.5 Amps at 5.15V, so the ATX power supply probably could provide enough for a classroom full of rPi computers, though I'd recommend a 5Amp fuse on every bench and a few precautions lik...

r4049zt

I've just booted and done some stuff with 5.15 Volts from doing something messy to the red-black-black-yellow wires in a PC wired to the same end of my raspberry Pi board as its usual 5V micro-usb power connector. Switch the PC off first and don't do this unless you have wires and can solder onto th...

r4049zt

If you can find something which does Mexican ac to >=1A and is in the range of 4.8 to 5V then it should work. One user mentioned an old Blackberry 5V 800mA supply and that should work. Don't waste money in order to get the latest micro-usb connector. Bare wires can be hand soldered to component D17....

r4049zt

You have a number of options, which avoid buying more power supplies if you presently have some already. Your 700mA 5V is indeed minimal and thanks for letting us know that it sort of works. Some USB splitters have a socket for independent power supply but cost a lot less if they don't come with one...

r4049zt

To Alias Neo, I'd swap one of your regulator components for a miscillaneous electronic component or two of equal value which I have in my stash. I have power FET's, 0.7Amp LED's, red, white or amber, and a few other bits and pieces. I'm trying stuff like that, and can do swaps. It costs us both a st...

r4049zt

I second that reply.
The micro-usb on the rPi is wired for power only.
If you wanted to transfer data, then having linux and samba is one way to make shared folders which your rPi could find over ethernet. There might be some other way but I don't know it.

r4049zt

Sorry to be of no help. I thought that netbeans was introduced around 2002 to slow down the 256MB computers and convince people that they might actually have a use for 512MB of RAM. If that is so then any ARM emulation of it on a 256MB computer might be slow. If you still have your source code then ...

r4049zt

Open Office might be a bit big and bloated for rPi ideals. IF you want a basic wordprocessor and spreadsheet, sufficient is sudo apt-get install abiword sudo apt-get install gnumeric Those can read and write .doc and .xls formats, but have less clutterware than the full open office mammoth. The choi...

r4049zt

I think that a 5.4 Volt supply won't quite work. My keyboard did not work off 5.4V nor 5.3, from four AA batteries. The rPi booted safely but keyboard was not working. I had to run them down to 5.25V to get less than 4.99 Volts on the rPi board. Then it worked, and I wrote a post to this forum. I th...

r4049zt

One way is to swap in an sd card with wheezy if you want to boot to debian, and swap in another sd card with something else on it if you want to boot to something else. We have got rather spoilt with grub and >32GB hard disk drives on a PC. The rPi does not have that. I've not seen huge sd cards at ...

r4049zt

Try opening a terminal and typing
cd /dev
ls u*

See linux help for more info

r4049zt

From its rating, it might work so give it a try. While it is on, prod component D17 on the reverse side of your rPi board with a multimeter. 4.8 to 4.9 Volts is normal. Much lower than that indicates insufficient power supply. Higher than 4.99V at this test point was observed to cause my keyboard to...

r4049zt

Since I was here last, I've done two things. I tried a solar panel advertised as 1.2W 6V, which turns out to do 0 to 200mA at 5 to 7 Volts, and found that OK with four NiCAD batteries, if checked with a multimeter and disconnected when batteries are full. I put a diode on mine so that I don't have t...

r4049zt

Another thing to check for is the exact voltage of your 1 Amp power supply. If it is in the range of 4.8 to 5.1 Volts then something else is the matter. I found that 5.3 and 5.5 Volts did not work, but 5.2 Volts or less did work. Normal operating condition is 4.7 to 4.9 Volts at component D17. You m...

Search found 113 matches

Re: Powered my pi but wont turn on

Re: power supply advice needed?

Re: Raspberry Pi as local web server and SD card life span

Re: Auto-solar powered webcam

Re: PWM as a voltage regulator

Re: Suggestion: Tiny PCB for DC-anything to 5 V DC

Re: Noob looking for a power cable.

Re: Noob looking for a power cable.

Re: Possible VGA monitor workaround?

Re: USB peripherals, performance and power management

Re: Accessing Internet?

Re: powered my raspberrypi using my computer

Re: powered my raspberrypi using my computer

Re: Noob looking for a power cable.

Re: Power setup

Re: Too high voltage? (PSP PSU 5.4 V)

Re: data transfer over usb power port?

Re: how to deploy NetBeans webapplication?

Re: libreoffice - how to install?

Re: Too high voltage? (PSP PSU 5.4 V)

Re: dual boot

Re: USB device management

Re: Adequate Power Supply

Re: Solar Powered Pi's

Re: Power from extension lead with USB