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by frak
Sat Jun 07, 2014 11:17 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: A question of power...
Replies: 11
Views: 1659

Re: A question of power...

Ah OK, I mistook the need for accuracy on voltage for a corresponding need to care about the current.

Thanks again.
by frak
Sat Jun 07, 2014 9:34 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: A question of power...
Replies: 11
Views: 1659

Re: A question of power...

One follow up question - I have 5800mAh coming out of the battery, and the amount of current the strip draws will vary with what is being displayed - how do I protect the LED strip from too much current?
by frak
Sat Jun 07, 2014 4:20 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: A question of power...
Replies: 11
Views: 1659

Re: A question of power...

I think on reflection I will go the extra mile and not power the LEDs through the GPIO pin and give them a separate connection to the battery. As you have made clear, there is a risk to the Pi and as cheap as it was to buy, I feel a real connection to it and wouldn't want to destroy it through negli...
by frak
Sat Jun 07, 2014 4:05 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: A question of power...
Replies: 11
Views: 1659

Re: A question of power...

If you had looked at either of the links in my question you would have seen what is involved in the project ;) OK, so I need to power the Pi through the USB and provide a separate 5V supply to the strip. However, the schematic here https://learn.adafruit.com/light-painting-with-raspberry-pi/hardware...
by frak
Sat Jun 07, 2014 3:52 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: A question of power...
Replies: 11
Views: 1659

Re: A question of power...

In case of nothing but LEDs attached, the GPIO outputs' limit are met before the overcurrent protection is activated. I am not sure I fully understand this. From what I have read about the LED strip https://learn.adafruit.com/light-painting-with-raspberry-pi/hardware , it requires about 2A of power...
by frak
Sat Jun 07, 2014 3:30 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: A question of power...
Replies: 11
Views: 1659

Re: A question of power...

This all makes sense, but the over current protection you mention - won't that stop the current getting through to the GPIO header that will power the LEDs?
by frak
Sat Jun 07, 2014 3:18 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: A question of power...
Replies: 11
Views: 1659

A question of power...

Hi! I am attempting to make a light scythe based on the Mechatronics Guy's project: https://sites.google.com/site/mechatronicsguy/lightscythe-v2 and my work so far can be found at http://frak.github.io/LightScythe I have purchased a Li-Ion battery pack that is capable of outputting 5800 mA/h which s...
by frak
Sat May 17, 2014 9:34 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Strange output from i2cdetect [solved]
Replies: 4
Views: 1723

Re: Strange output from i2cdetect

Hah! It was the 1wire stuff that I had enabled that I didn't need. I just disabled those modules in /etc/modules and I get the expected output pi@scythe ~ $ sudo i2cdetect -y 0 0 1 2 3 4 5 6 7 8 9 a b c d e f 00: -- -- -- -- -- -- -- -- -- -- -- -- -- 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- --...
by frak
Sat May 17, 2014 9:25 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Strange output from i2cdetect [solved]
Replies: 4
Views: 1723

Re: Strange output from i2cdetect

Yeah, I disconnected it as soon as I saw the weird output - and I have tried this on two different devices (both rev a)
by frak
Sat May 17, 2014 8:32 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Strange output from i2cdetect [solved]
Replies: 4
Views: 1723

Strange output from i2cdetect [solved]

I am trying to get the Adafruit 16x2 LCD working, but I think I have messed up the settings somehow. I have enabled the i2c module and can see it in lsmod: pi@scythe ~ $ lsmod Module Size Used by rfcomm 33136 0 bnep 11030 2 bluetooth 225849 10 bnep,rfcomm rfkill 19567 2 bluetooth w1_therm 2870 0 w1_...
by frak
Wed Sep 05, 2012 4:46 pm
Forum: Other programming languages
Topic: Using PHP to control SPI devices
Replies: 4
Views: 6125

Using PHP to control SPI devices

I have made a PHP extension that provides an object oriented interface to the SPI devices. To build the extension, you will need to have php5-dev installed, and the instructions in the README should guide you through the install process. The repository can be found here https://github.com/frak/php_s...
by frak
Wed Aug 22, 2012 8:14 pm
Forum: Other programming languages
Topic: PHP GPIO Library
Replies: 28
Views: 40289

Re: PHP GPIO Library

There are now PHP bindings to the WiringPi library available on Github: https://github.com/WiringPi/WiringPi-PHP
by frak
Sun Jul 22, 2012 10:25 pm
Forum: Raspbian
Topic: Need basic web server SSL and password support??
Replies: 9
Views: 2989

Re: Need basic web server SSL and password support??

Fair enough, but in 12 years of web development it (Apache) has never done me wrong ;o)
by frak
Sun Jul 22, 2012 10:19 pm
Forum: Raspbian
Topic: Need basic web server SSL and password support??
Replies: 9
Views: 2989

Re: Need basic web server SSL and password support??

What specific issues are you having with Apache that is forcing you to try another web server? You can reduce memory requirements a lot by disabling unneeded modules...
by frak
Sun Jul 22, 2012 9:53 pm
Forum: Raspbian
Topic: Building ffmpeg
Replies: 2
Views: 803

Re: Building ffmpeg

Thanks - it does seem to be building fine, I was just curious.

Kudos on the build, much more polished and a joy to work with :o)
by frak
Sun Jul 22, 2012 9:48 pm
Forum: Raspbian
Topic: Remove X11
Replies: 1
Views: 949

Remove X11

So I am planning to use my Pi (with some others when I can get them) as transcoding boxes, and as such I will only be accessing them via SSH. I am running it on an 8GB card, so space isn't really an issue, but I was wondering if there would be any benefit for me in removing the X11 packages that are...
by frak
Sun Jul 22, 2012 9:36 pm
Forum: Raspbian
Topic: Building ffmpeg
Replies: 2
Views: 803

Building ffmpeg

I would like to build ffmpeg with libfaac and x264 on my Pi, are there any specific configure flags that I can use to make best use of the Pi hardware, specifically the hardfloat implementation that Raspbian offers?

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