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by Twinkletoes
Mon Sep 08, 2014 4:23 pm
Forum: Beginners
Topic: Advice for a portable, battery powered Pi camera
Replies: 10
Views: 1057

Re: Suggestions for cat-mounted pi-powered video camera!

I'm seeing about 5 watts with pi model B with wifi.
by Twinkletoes
Tue Sep 02, 2014 11:35 am
Forum: Networking and servers
Topic: Network Manager eating 30% CPU
Replies: 3
Views: 662

Re: Network Manager eating 30% CPU

Dougie - What problems did you have?
by Twinkletoes
Tue Sep 02, 2014 7:10 am
Forum: Automation, sensing and robotics
Topic: Swimming lap counter
Replies: 5
Views: 2097

Re: Swimming lap counter

You're going to find it hard (if you're not alone in the pool) to detect yourself but not anyone else. So you need some way to recognise your head in the water amongst all the others. If you wear goggles, you could put an IR LED on both sides, with a simple square wave oscillator (and a button batte...
by Twinkletoes
Mon Sep 01, 2014 8:42 pm
Forum: Networking and servers
Topic: Network Manager eating 30% CPU
Replies: 3
Views: 662

Network Manager eating 30% CPU

Without network manager with the Pi idle, we see about 1-5% CPU as various tasks tick along. When we start the network manager service, CPU load jumps to 30-40%. We like network manager - it deals very nicely with switching from wired to wifi and between access points. But I'd like it if it left som...
by Twinkletoes
Wed Aug 27, 2014 12:51 pm
Forum: Beginners
Topic: Making a train for my son I need your help
Replies: 4
Views: 603

Re: Making a train for my son I need your help

Simplest way to make a smoke machine is to use a travel iron. Use smoke fluid instead of water in its tank. You might well find you can run it off 12V. I bought one for £10 new and dremeled it. The advantage is that you get a really good lumpy cloud off it rather than the wimpy stream of smoke you g...
by Twinkletoes
Mon Aug 18, 2014 12:18 pm
Forum: General discussion
Topic: US Flight Restrictions
Replies: 4
Views: 800

Re: US Flight Restrictions

I usually take them literally with one computer per tray. Needed 17 trays last time I flew with a carryon full of pis... Much confusion when I asked TSA if they just wanted laptops and tablets, or all computers. All computers is what they got... :)
by Twinkletoes
Fri Jul 25, 2014 11:56 am
Forum: Media centres
Topic: RaspMedia Digital Signage Player
Replies: 5
Views: 3111

Re: RaspMedia Digital Signage Player

Deleted my post as it's considered off topic
by Twinkletoes
Fri Jul 25, 2014 10:58 am
Forum: Media centres
Topic: RaspMedia Digital Signage Player
Replies: 5
Views: 3111

Re: RaspMedia Digital Signage Player

Deleted my post as considered off topic. Good luck with the digital signage
by Twinkletoes
Tue Jun 17, 2014 8:43 am
Forum: Python
Topic: PI3D openGL png with alpha blended layers have rough edges?
Replies: 6
Views: 2376

Re: PI3D openGL png with alpha blended layers have rough edg

Make sure there is no pink in your hand png. Make the cutout only in the alpha layer, or your soft alpha will hit pixels blended with your png background.
by Twinkletoes
Fri Jun 13, 2014 12:42 pm
Forum: Other
Topic: Windows Embedded Compact 2013
Replies: 22
Views: 26938

Re: Windows Embedded Compact 2013

If your Windows application is .Net (Java#, C#, F#, VB.Net, Cobol# etc) then you should be able to run it on Mono on Raspbian. The only major holes are that it won't support WPF. But we're happily running .Net 4.0 Winforms and console apps on Mono 3.4.
by Twinkletoes
Fri Jun 13, 2014 12:31 pm
Forum: Beginners
Topic: Creating a pwm signal by hand
Replies: 29
Views: 6095

Re: Creating a pwm signal by hand

Look at how https://github.com/richardghirst/PiBits/tree/master/ServoBlaster does it. From the readme: The driver works by setting up a linked list of DMA control blocks with the last one linked back to the first, so once initialised the DMA controller cycles round continuously and the driver does n...
by Twinkletoes
Mon Jun 09, 2014 7:51 pm
Forum: Compute Module
Topic: PC Board Design Software
Replies: 6
Views: 4853

Re: PC Board Design Software

Is there a way to do differential pairs on kicad? Can't find any reference in the docs.

What's the cheapest PCB design tool you're aware of that does support constant impedance differential pairs (e.g. HDMI and LAN tracks)?
by Twinkletoes
Mon Jun 09, 2014 7:46 pm
Forum: Networking and servers
Topic: Sending UDP data to RPI
Replies: 23
Views: 3098

Re: Sending UDP data to RPI

There's no multicast on the RPi...
1. OP is using a broadcast, so no need for multicast
2. Zeroconf (avahi) works, and that revolves around multicast (224.0.0.251), so multicast does work on the Pi.
by Twinkletoes
Fri Jun 06, 2014 2:50 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Make a ring switch like Nest
Replies: 10
Views: 2980

Re: Make a ring switch like Nest

Between these two posts, it's clear (1) you only need one toothed wheel, and (2) you mount the two sensors so they're offset by half a tooth - or an odd multiple of half a tooth. Nice improvement on my design! I'd invert this sketch so the teeth are on the inside of the ring so that you keep the ce...
by Twinkletoes
Thu Jun 05, 2014 3:27 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Make a ring switch like Nest
Replies: 10
Views: 2980

Re: Make a ring switch like Nest

You could use a rotation sensor. It is usually built as two toothed wheels, offset by half a tooth from each other, mounted on the same axle. You put an optical sensor across each of the two wheels. It's a simple logic problem to look at the train of pulses coming off each one to see the direction o...
by Twinkletoes
Wed May 28, 2014 2:42 pm
Forum: Troubleshooting
Topic: STICKY: Setting up HDMI output when video output is wrong.
Replies: 522
Views: 818673

Re: Setting up HDMI output

WigJohn - Log into the pi edit the config.txt file (sudo gives you rights to do it, nano is a text editor): sudo nano /boot/config.txt There will be a line in there #hdmi_force_hotplug=something Remove the # (this makes it a comment, so removing it makes it do something) Change to hdmi_force_hotplug...
by Twinkletoes
Thu May 15, 2014 12:40 am
Forum: Advanced users
Topic: LLVM backend for QPU development
Replies: 29
Views: 9617

GPU Processing API - 2

who is actually after a high-level GPU processing API for the RPI?
Me.

Ideas:

Facial (or gender/age) recognition.
Audio mixer with DSP per channel.
by Twinkletoes
Wed May 14, 2014 7:39 pm
Forum: General discussion
Topic: build videocore driver: Video :)
Replies: 18
Views: 2066

Re: build videocore driver

You might cause a rip in the time vortex
by Twinkletoes
Tue May 13, 2014 8:25 am
Forum: General programming discussion
Topic: PC to RPi GPIO + Video Streaming to PC
Replies: 4
Views: 1474

Re: PC to RPi GPIO + Video Streaming to PC

You could use lighttpd to set up a very simple web server on the pi. Use php in the /var/www folder to control the pan tilt. for example you could have /var/www/nudgeleft.php /var/www/nudgeright.php /var/www/nudgeup.php /var/www/nudgedown.php And then fire them from a PC using a url GET to http://ra...
by Twinkletoes
Sun May 11, 2014 9:37 am
Forum: Python
Topic: What other programming language can i use with Raspberry Pi?
Replies: 22
Views: 1998

Re: What other programming language can i use with Raspberry

You can use hundreds of languages on the Pi. You happen to use one which is closed source.
For the record mono is open source. Not willing to get into a foss war but if you find a bug you can get the code and fix it.
by Twinkletoes
Sat May 10, 2014 2:25 pm
Forum: Python
Topic: What other programming language can i use with Raspberry Pi?
Replies: 22
Views: 1998

Re: What other programming language can i use with Raspberry

If only that were true! I could go home early...

It's more that certain types of task are made very quick and reliable by resharper and VS so no debugging is required afterwards. Something big like refactoring methods and namespaces across 25 projects can be a single operation in Resharper.
by Twinkletoes
Sat May 10, 2014 12:57 pm
Forum: Python
Topic: What other programming language can i use with Raspberry Pi?
Replies: 22
Views: 1998

Re: What other programming language can i use with Raspberry

In any case we've been able to get improvements of 50-90% in speed multiple times over by changing algorithms (binary search, caching of intermediate results etc) rather than unrolling loops or any other low level changes.
by Twinkletoes
Sat May 10, 2014 12:56 pm
Forum: Python
Topic: What other programming language can i use with Raspberry Pi?
Replies: 22
Views: 1998

Re: What other programming language can i use with Raspberry

The only difference really is the hit of managed code, which is mainly garbage collection, and the differences in the compilers. It's still being compiled to native code.
by Twinkletoes
Sat May 10, 2014 10:30 am
Forum: Python
Topic: What other programming language can i use with Raspberry Pi?
Replies: 22
Views: 1998

Re: What other programming language can i use with Raspberry

No comparative raw speed tests done. But I'm running a full blown scheduled media player written in C# (250k+ lines of code) and it is outperforming an Intel Atom thanks to the GPU. The speed of development trumps any small speed decrease for me. Plus the ability to unit test on Windows and in the c...
by Twinkletoes
Thu May 08, 2014 8:23 am
Forum: Python
Topic: What other programming language can i use with Raspberry Pi?
Replies: 22
Views: 1998

Re: What other programming language can i use with Raspberry

Here's the way I work: I develop in C# in Visual Studio on Windows. If I need low level functionality (e.g. GPIO) I write a tiny library in C and a p/Invoke wrapper around it in C#. I deploy my exe and dlls to the Pi. I install mono 3.2.8 (sudo apt-get install mono-complete) I run my app: mono MyApp...

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