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by Techmeology
Sat Jul 13, 2013 1:41 am
Forum: Other projects
Topic: Yet Another PIC Programmer for the Raspberry Pi
Replies: 21
Views: 7426

Re: Yet Another PIC Programmer for the Raspberry Pi

Hi avstomusic: The VDD control pin is used to control whether power is received by the PIC. The circuit itself is not powered by the Pi. cae2100: Thanks for the suggestions. If I were to make many of these, I might well try to power it from the Pi alone. Some of the design of the programmer arises f...
by Techmeology
Mon Feb 25, 2013 4:55 pm
Forum: Other projects
Topic: Yet Another PIC Programmer for the Raspberry Pi
Replies: 21
Views: 7426

Re: Yet Another PIC Programmer for the Raspberry Pi

If you want to do a magpi article, sure! Let me know if I can help with that. The board itself isn't designed to use RS232, but I designed the software to be reasonably modular - you might well be able to use an RS232 adapter. Techmeology p.s: Damn, I didn't notice a notification email about your re...
by Techmeology
Mon Oct 08, 2012 4:44 pm
Forum: General discussion
Topic: Forum search internal filtering
Replies: 2
Views: 717

Re: Forum search internal filtering

The same thing happens if you search for GPIO. It is annoying, alas I suspect it's done to avoid queries that might nom all the server's CPU cycles. As a work around, you could google something like:

Code: Select all

P5 site:http://www.raspberrypi.org/phpBB3
by Techmeology
Sun Oct 07, 2012 9:46 pm
Forum: Other projects
Topic: Yet Another PIC Programmer for the Raspberry Pi
Replies: 21
Views: 7426

Yet Another PIC Programmer for the Raspberry Pi

Hello, all! I've been working on (yet another) PIC Programmer for the Raspberry Pi: http://www.techmeology.co.uk/rpipic/ . This particular one features: The ability to program 12 bit and 14 bit PICs Autodetection of 14 bit PICs A modular architecture that could be extended to support other chips Dia...
by Techmeology
Thu May 10, 2012 10:16 am
Forum: Beginners
Topic: USB Hub Issues
Replies: 5
Views: 1856

Re: USB Hub Issues

<t>I think you're unlikely to cause permanent damage to your Pi that way, however if you try to draw too much power, you may find that it becomes unreliable until you unplug stuff:<br/> <br/> -Ethernet port may stop working correctly<br/> -USB may stop working correctly<br/> -The Pi may just switch ...
by Techmeology
Tue May 01, 2012 9:51 am
Forum: Beginners
Topic: Multiple boot images on one SD card?
Replies: 18
Views: 10656

Re: Multiple boot images on one SD card?

That's already possible by changing cmdline.txt's root option (and optionally changing the kernel image).
by Techmeology
Tue May 01, 2012 1:43 am
Forum: Beginners
Topic: Startup time
Replies: 7
Views: 2312

Re: Startup time

<t>If you need to limit it to one app for security reasons, then be careful that you still do things like change the root and user passwords (defend against ctrl+alt+f1), ensure the various stuffs that allow the user to kill X are disabled, hide the Pi in a locked box, and so on.<br/> <br/> To custo...
by Techmeology
Mon Apr 30, 2012 9:25 pm
Forum: Beginners
Topic: Multiple boot images on one SD card?
Replies: 18
Views: 10656

Re: Multiple boot images on one SD card?

<t>Although the RPi distros are generally distributed as images, it's possible to extract the partitions, and shuffle them around as you see fit. I expect it would also be possible to create installers (that either expand them selves onto the SD card, or that read from a memory stick, create and wri...
by Techmeology
Mon Apr 30, 2012 9:08 am
Forum: Beginners
Topic: Multiple boot images on one SD card?
Replies: 18
Views: 10656

Re: Multiple boot images on one SD card?

<t>To do this properly, you'd need some kind of bootloader that presents a menu on start up. However, you could use cmdline.txt to change the root partition. So you could have one distribution on partition 2, and another on partition 3, and use the root=/dev/mmcblk0p2 or root=root=/dev/mmcblk0p3 to ...
by Techmeology
Sat Apr 28, 2012 2:02 pm
Forum: Beginners
Topic: Using a wired keyboard - pitfall
Replies: 5
Views: 2752

Re: Using a wired keyboard - pitfall

<r>Some powered hubs have been known to cause problems (<URL url="http://elinux.org/RPi_Verified.....d_USB_Hubs">http://elinux.org/RPi_Verified.....d_USB_Hubs</URL>). It sounds to me as if your Pi doesn't have enough power for the keyboard when you plug it in directly. What power supply are you usin...
by Techmeology
Sat Apr 28, 2012 1:59 pm
Forum: Beginners
Topic: Using Raspberry Pi to control electric devices
Replies: 5
Views: 5050

Re: Using Raspberry Pi to control electric devices

If you choose to use GPIO16, you'll have to try a method like the C method (or possibly the Python method might work) which works by directly writing to the memory mapped registers, as echo 16 > /sys/class/gpio/export yields an error.
by Techmeology
Fri Apr 27, 2012 11:48 pm
Forum: Beginners
Topic: Using Raspberry Pi to control electric devices
Replies: 5
Views: 5050

Re: Using Raspberry Pi to control electric devices

Yes it is, but be careful not to blow up your RPi! Consider using a Gertboard, or at the very least a buffering circuit. http://elinux.org/RPi_Tutorial.....n_Circuits
by Techmeology
Fri Apr 27, 2012 2:24 pm
Forum: General discussion
Topic: A or B
Replies: 5
Views: 1815

Re: A or B

The simple answer is yes, however there are a few caveats:

If you had high bandwidth requirements over both the USB and the Ethernet then a bottleneck might appear sooner than with a dedicated Ethernet port. Ethernet via a USB device might also consume more CPU time.
by Techmeology
Fri Apr 27, 2012 2:19 pm
Forum: General discussion
Topic: Will the RP play any 1080p mkv?
Replies: 3
Views: 6535

Re: Will the RP play any 1080p mkv?

<r>Once everything's up and running, it should be able to play h264 mkv. To play 1080p in real time, GPU acceleration is required. The Raspberry Pi foundation has licenced h264, but there are other codecs for the bcm2865's GPU. These aren't included in the Debian image, but least some of them seem t...
by Techmeology
Fri Apr 27, 2012 2:10 pm
Forum: Beginners
Topic: 3D Bluray Support
Replies: 4
Views: 4187

Re: 3D Bluray Support

by Techmeology
Fri Apr 27, 2012 11:51 am
Forum: Beginners
Topic: 3D Bluray Support
Replies: 4
Views: 4187

Re: 3D Bluray Support

<t>There are more VLLs available in the ArchLinux image (at least the 01-03-2012 version – I haven't checked the later version). None of them seem to do 3D Blurray unless it's in one of the related codecs, so it may be that what you want simply does not exist.<br/> <br/> A complete list of the avail...
by Techmeology
Fri Apr 27, 2012 12:07 am
Forum: Beginners
Topic: Really Simple Hardware Control
Replies: 5
Views: 4003

Re: Really Simple Hardware Control

<r>If you want even simpler control, use the interface in /sys/class/gpio. So if you use GPIO 25 (that's pin 1-22 - top row, third from the right):<br/> <br/> su root<br/> echo 25 > /sys/class/gpio/export<br/> echo out > /sys/class/gpio/gpio25/direction<br/> echo 1 > /sys/class/gpio/gpio25/value #se...
by Techmeology
Thu Apr 26, 2012 11:50 pm
Forum: Beginners
Topic: Reading values from GPIO input pins?
Replies: 5
Views: 15827

Re: Reading values from GPIO input pins?

<t>In my opinion, the easiest way to use the GPIO is the way implied by the shell script (should work from any language that supports file IO) as it"s just file IO, and has no need to know special knowledge of BCM2835 (and therefore less likely to have subtle bugs):<br/> <br/> void init_gpio(int n)<...
by Techmeology
Thu Apr 26, 2012 9:00 am
Forum: Beginners
Topic: Process for installing software
Replies: 1
Views: 1333

Re: Process for installing software

The Raspberry Pi runs Linux, so it should be able to read pretty much any USB flash drive you use if it's formatted with FAT32 or NTFS (most are one of these) or one of several other formats.
by Techmeology
Tue Apr 24, 2012 1:49 pm
Forum: Troubleshooting
Topic: Error after updating start.elf
Replies: 4
Views: 4250

Re: Error after updating start.elf

<t>timmillwood: Does it work after reimaging? - I've used the 224 MB start.elf with the latest Debian image, and it seems to work OK. My suspicion is that your problem is not related to the change of start.elf - like rew said, it looks like an SD card issue.<br/> <br/> rew: I had kinda wondered whet...
by Techmeology
Sat Apr 21, 2012 11:38 pm
Forum: Beginners
Topic: Faster and Bigger SD Cards
Replies: 5
Views: 3135

Re: Faster and Bigger SD Cards

According to the wiki, the problem that affects class 10 cards "seems to have been fixed": http://elinux.org/RPi_Verified.....m_SD_Cards
by Techmeology
Sat Apr 21, 2012 12:02 am
Forum: Beginners
Topic: Faster and Bigger SD Cards
Replies: 5
Views: 3135

Re: Faster and Bigger SD Cards

<r>Bigger – certainly. This will allow you to install more programs, and store more documents on the card (of course, you could also rig up something with an external hard drive). Just remember to increase the size of your root partition (the default for most of the images is less than 2 GB to fit o...
by Techmeology
Fri Apr 20, 2012 7:38 pm
Forum: Beginners
Topic: asterisk
Replies: 7
Views: 3072

Re: asterisk

Well, you wouldn't need the USB microphone:p I guess it depends on how CPU/memory intensive that is. The best way to find out would be to try it...
In terms of traffic alone, you may be interested to know that my RPi is able to wget to /dev/null at over 80 MBit/s.
by Techmeology
Fri Apr 20, 2012 6:42 pm
Forum: Beginners
Topic: asterisk
Replies: 7
Views: 3072

Re: asterisk

At the moment, the audio drivers are experimental, however when they're working, it should be possible to use the RPi for VoIP - provided you use a USB microphone (the RPi does not have a microphone port).
by Techmeology
Fri Apr 20, 2012 4:26 pm
Forum: Beginners
Topic: Htop Reports 122MB RAM
Replies: 3
Views: 2200

Re: Htop Reports 122MB RAM

<t>Indeed, the swap is not mounted by default. Also, swappiness is set to 1, so even with the swap partition mounted, the card should not be written to most of the time unless it is necessary.<br/> <br/> As for the 122 MB of memory, if this is the total memory (as opposed to free memory), I expect y...

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