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by richardp
Sat May 18, 2013 1:47 pm
Forum: Other projects
Topic: Cress-Growing Timelapse
Replies: 4
Views: 1097

Re: Cress-Growing Timelapse

Nice one! Are the cress growing in a constant light? Or is there an infrared light source so that night-time activities can be observed? Webcams are good in the infrared spectrum.

Richard
by richardp
Sat May 18, 2013 10:26 am
Forum: Camera board
Topic: Project suggestion - stream Living Room TV
Replies: 9
Views: 3337

Re: Project suggestion - stream Living Room TV

I wanted to do the same.. using a video grabber from ebay. (stk based) - Video was so bad it was not usable ( Search for USB Redux ), using a test stream the H264 encode was less than ideal, it was very hit-n-miss getting the frames - so I binned the idea. Richard Edit : This was 3 months ago... the...
by richardp
Tue May 14, 2013 3:44 pm
Forum: General discussion
Topic: Anemometer
Replies: 42
Views: 25884

Re: Anemometer

http://www.maplin.co.uk/n25fr-wind-speed-sensor-676620

I can't build it for less than £2.50 - So I would buy one and hack it up.
by richardp
Tue May 14, 2013 1:35 pm
Forum: Arch
Topic: TV is ON?
Replies: 2
Views: 807

Re: TV is ON?

yes you can.. but its riddled with problems..

1) You TV should support CEC
2) Some TV's shut down the HDMI port then its not selected on the TV (HDMI1, HDMI2) - In that case you get the HDMI disconnect.
3) Some TV's shut down the HDMI logic in Standby

Richard
by richardp
Mon May 13, 2013 7:19 pm
Forum: General discussion
Topic: Cron Task URL Access
Replies: 4
Views: 2657

Re: Cron Task URL Access

rpdom Many thanks for getting back to me so quickly, yep my syntax was poor but I've just tried the following command: 02 20 * * * /usr/bin/wget -O - -q -t 1 http://192.168.1.20:88/cgi-bin/CGIProxy.fcgi?cmd=rebootSystem&usr=xxxx&pwd=xxxx And it also did not work, any other suggestions greatly welco...
by richardp
Sun May 12, 2013 1:56 pm
Forum: Off topic discussion
Topic: Raspberry Pi Vs. Alternatives
Replies: 62
Views: 42382

Re: Raspberry Pi Vs. Alternatives

This brings back memory of my childhood...

"My Sinclair is better than your Commodore64".. even though Sinclair owners secretly wanted a commodore too!
by richardp
Sun May 12, 2013 12:55 pm
Forum: Other projects
Topic: Creepy crawly
Replies: 5
Views: 1706

Re: Creepy crawly

Thought I'd have a bit of fun with some polymorph and create a pi bow spider case http://i404.photobucket.com/albums/pp129/matto2494/image_zpsb08adf7d.jpg I just couldn't figure out from the topic why someone would put a raspberry on a pool cleaner.. http://www.phil-schwartz.com/reviews/kreepykraul...
by richardp
Sat May 11, 2013 10:49 am
Forum: Troubleshooting
Topic: USB FIQ testing....
Replies: 181
Views: 72167

Re: USB FIQ testing....

It would be interesting to push the stream to a file and see what you can do with it. I've seen higher bitrates working fine with other dvb dongles but you just can't process the data on the arm... Gordon DVB-S works (Technotrend S2400), I used to have data-loss but now it seems to be good - its ch...
by richardp
Fri May 10, 2013 3:13 pm
Forum: Troubleshooting
Topic: USB FIQ testing....
Replies: 181
Views: 72167

Re: USB FIQ testing....

Thanks gsh,

The update fixed a dvb tuner, so awesome! Kudos! - but the el-cheezy-usb audio still have problems. Using one usb stick the audio works*, but using 2 devices its very broken audio.

*the audio glitches but its still okay.

Richard
by richardp
Thu May 09, 2013 7:02 pm
Forum: Graphics, sound and multimedia
Topic: DVB-T UK all 6 muxes with TVHeadend
Replies: 10
Views: 13798

Re: DVB-T UK all 6 muxes with TVHeadend

The Hardware PID filter is not a common feature of cheaper USB DVB-T sticks... but in this mode only the channel being used is sent to the Pi... in Multiplex mode the whole Mux is send to the Pi and the raspberry has to filter the unwanted channels out. I get 50% CPU usage just watching ITV1 on DVB-...
by richardp
Thu May 09, 2013 3:52 pm
Forum: Graphics, sound and multimedia
Topic: DVB-T UK all 6 muxes with TVHeadend
Replies: 10
Views: 13798

Re: DVB-T UK all 6 muxes with TVHeadend

I have got a DVB-S card attached to a Pi (512M) and it streams 1 channel nicely.. 2 channels it breaks up and the CPU is fully utilised. Your mileage may vary, but if the DVB-T hardware has a hardware PID filter then it should lessen the Raspberry loading. If there is only one client, then It should...
by richardp
Tue May 07, 2013 6:39 am
Forum: Automation, sensing and robotics
Topic: Servo drag & motor
Replies: 5
Views: 1075

Re: Servo drag & motor

Addition - The HS-81 Servos are reported to hit a peak of about 700mA (according to a website that tests these things)
by richardp
Mon May 06, 2013 7:42 pm
Forum: Automation, sensing and robotics
Topic: Servo drag & motor
Replies: 5
Views: 1075

Re: Servo drag & motor

No idea on a calculation... but the bigger the capacitor the more energy is available. 4700uF and then just see what happens.

I still think its the PSU that cant handle the inrush current loads.
Richard
by richardp
Mon May 06, 2013 7:38 am
Forum: Automation, sensing and robotics
Topic: Servo drag & motor
Replies: 5
Views: 1075

Re: Servo drag & motor

Depending on the size of the motors, a capacitor should help, but depending on what energy you need and for how long will determine the size; Every motor has a large startup current to overcome the stiction. Although your power supply is 2A and the motor is perhaps 300mA, it will consume multiples o...
by richardp
Sun May 05, 2013 2:09 pm
Forum: Media centres
Topic: TVHeadend Performance
Replies: 2
Views: 1667

Re: TVHeadend Performance

Changing the epoll a bit.. it got a bit better, but still the system is heavy on strcpy() and some other operations. + 14.43% tvheadend [kernel.kallsyms] [k] memcpy + 11.30% tvheadend [kernel.kallsyms] [k] finish_task_switch.constprop.67 + 6.71% tvheadend [kernel.kallsyms] [k] __do_softirq + 4.51% t...
by richardp
Sun May 05, 2013 10:25 am
Forum: Media centres
Topic: TVHeadend Performance
Replies: 2
Views: 1667

TVHeadend Performance

After getting TVHeadend working *yay* I notice that it uses alot of CPU cycles for doing almost nothing running perf -g tvheadend shows the below.. input_dvr seems to have an ugly epoll and the raw_dispatch is using quite a bit of cycles... even when there are no services tuned. Is background scanni...
by richardp
Fri May 03, 2013 10:21 am
Forum: Raspbian
Topic: 'Binding' keys in script (was 'Detecting mouse clicks')
Replies: 8
Views: 2475

Re: Detecting mouse clicks

take a look at the /dev/input/events files.. depending on what you are doing there will be triggers on what keys/mouse/etc operations are occurring.

Richard
by richardp
Fri May 03, 2013 9:08 am
Forum: Troubleshooting
Topic: USB FIQ testing....
Replies: 181
Views: 72167

Re: USB FIQ testing....

USB_idle_trace.png Here is a trace from a idle USB hub (with a sound adapter attached) The trace file is filled up with Incomplete transactions quite quickly. The Kernel being used is not the latest, but a week old (with FIQ, but not the latest change) gsh, My offer still stands.. If you are in cam...
by richardp
Mon Apr 29, 2013 6:31 pm
Forum: C/C++
Topic: Writing own device driver
Replies: 4
Views: 3839

Re: Writing own device driver

Hi, is there a tutorial (or similar) about writing driverso for Raspberry? I would like to make my own (I know this feature is already available, but I would make it by myself) timing system: PPS output on GPIO, I sync time through NTP, if not available GPS receiver connected. How can I use hardwar...
by richardp
Mon Apr 29, 2013 12:16 pm
Forum: Troubleshooting
Topic: USB redux
Replies: 514
Views: 201337

Re: USB redux

You want a fully working USB 2.0 implementation that works with every device ever made for USB. You won't get that. You'll probably never get that with a Raspi for the reasons outlined above. There are issues that the majority of people don't see. You do see issues. Therefor the device is NOT fit f...
by richardp
Mon Apr 29, 2013 10:21 am
Forum: Troubleshooting
Topic: USB redux
Replies: 514
Views: 201337

Re: USB redux

In general moving the FIQ code to the GPU is quite simple but doesn't really get you very much (it's just removing a very small piece of code that probably executes something like 0.01% of the CPU). To move any more complexity into the GPU means ripping the driver apart, and as I've spent quite a l...
by richardp
Mon Apr 29, 2013 10:16 am
Forum: Troubleshooting
Topic: USB redux
Replies: 514
Views: 201337

Re: USB redux

Hmm. I really think you should give up on the Pi and get something else. I wont even justify that with a response.. You seem to be expecting the earth, and that ain't gonna happen. In my book taking audio from one USB device and outputting on another is an unusual use case - I've never done it, on ...
by richardp
Mon Apr 29, 2013 6:24 am
Forum: Troubleshooting
Topic: USB redux
Replies: 514
Views: 201337

Re: USB redux

The vast majority of people see no issues whatsoever, so rather than Essex, I'd say a small village in Scotland, Largs perhaps. Most people never go to Largs (although it is a nice place), so most people never see the problems (I was born in Essex, and I never see any problems). Still, if the probl...
by richardp
Sun Apr 28, 2013 8:23 pm
Forum: Troubleshooting
Topic: USB redux
Replies: 514
Views: 201337

Re: USB redux

@M33P, thanks for the reply. I appreciate all the effort in the drivers and a technical viewpoint, but at a consumer the USB is basically not fit for my purpose. (I don't rate echoing audio from one USB adapter to another as a big CPU eater- I have the same code running on a single core 800Mhz ARM7 ...
by richardp
Sun Apr 28, 2013 4:18 pm
Forum: Troubleshooting
Topic: USB redux
Replies: 514
Views: 201337

Re: USB redux

Any new developments on the USB Reliability? I read lots on the new cameras and such things , but yet a FUNDAMENTAL function on the RaspberryPi is yet to be clarified, or even fixed. Is there a timeline for the USB code to be fixed? or is 'Whenever' acceptable ? - Progress has been made, I do accept...

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