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by Neil
Mon Apr 13, 2015 2:18 pm
Forum: C/C++
Topic: math problems in C
Replies: 12
Views: 3247

Re: math problems in C

Why is it correct only in that infinitely pedantic last try? Compilers are pedantic. If you're not, then you can expect the compiler to misunderstand what you have not told it. #define SERIESRESISTOR 10000 Do you know what the type of SERIESRESISTOR is? #define DOUBLERESISTOR 10000.0 int main( void...
by Neil
Wed Mar 25, 2015 2:58 pm
Forum: General discussion
Topic: POE support on Rpi 3
Replies: 107
Views: 17618

Re: POE support on Rpi 3

Oh, and just for fun, can anyone say why that 1000pF commoning capacitor should be rated at 2kV? In case you touch the cable after petting the cat? Funny! But no... for that you'd use a spark gap to cope with the 5kV or so you'd generate from stroking fur. Bonus points if you use an ebonite rod. Al...
by Neil
Wed Mar 25, 2015 1:42 pm
Forum: General discussion
Topic: POE support on Rpi 3
Replies: 107
Views: 17618

Re: POE support on Rpi 3

Having both fixed one company's PoE interface and then subsequently designed my own (both commercial projects - anyone used Zigbee development kit from a certain vendor may have used my designs) I can with some experience say that designing-in PoE looks simple but is full of subtleties that are ther...
by Neil
Mon Feb 09, 2015 10:19 am
Forum: Troubleshooting
Topic: Why is the PI2 camera-shy ?
Replies: 162
Views: 266104

Re: Why is the PI2 camera-shy ?

(The big surprise to me is that there are semiconductor devices--other than those intended to be photosensitive--that aren't encapsulated. I would have thought that simple physical protection would have dictated that.) Cost. The epoxy encapsulation will most likely be done by a separate company tha...
by Neil
Sun Feb 08, 2015 10:22 pm
Forum: Troubleshooting
Topic: Why is the PI2 camera-shy ?
Replies: 162
Views: 266104

Re: Why is the PI2 camera-shy ?

jdb wrote:Also: it's amazing how many first posters on here haven't read the thread.
Welcome to the internet.
by Neil
Sun Feb 08, 2015 7:57 pm
Forum: Troubleshooting
Topic: Why is the PI2 camera-shy ?
Replies: 162
Views: 266104

Re: Why is the PI2 camera-shy ?

This is all really interesting. Hard to believe that this issue slipped through the net. I don't find it hard to believe. How many bits of electronics are tested by firing a flash gun at them? Did anyone here ever think this could cause a problem? I doubt it. I've never even heard of a failure case...
by Neil
Sun Feb 08, 2015 7:34 pm
Forum: Troubleshooting
Topic: Why is the PI2 camera-shy ?
Replies: 162
Views: 266104

Re: Why is the PI2 camera-shy ?

All bare-die (e.g., WLCSP) packages are sensitive to light, especially at the infra-red end where silicon is virtually transparent, and indeed makes rather good IR lenses such as these ones: http://www.edmundoptics.co.uk/optics/optical-lenses/ir-lenses/silicon-plano-convex-pcx-lenses/3368 It's a wel...
by Neil
Tue Nov 25, 2014 11:42 pm
Forum: Beginners
Topic: getting sky sports
Replies: 5
Views: 2115

Re: getting sky sports

Buy a Sky Now TV box, only £10. Pretty much like a RasPi inside ;)
by Neil
Tue Nov 25, 2014 11:40 pm
Forum: General programming discussion
Topic: SMI Documentation ?
Replies: 17
Views: 7227

Re: SMI Documentation ?

The Host Interface might also do what you want. It can be configured to do DMA transfers on a single 16-bit-wide channel, and the hardware supports the scheduling of transfer blocks for you. But I'm in the same boat as Gert and James so I'm just going by my fading grey cells.....

Neil
by Neil
Mon Jun 16, 2014 11:35 am
Forum: Automation, sensing and robotics
Topic: Mechanical volume control with midi
Replies: 10
Views: 4889

Re: Mechanical volume control with midi

MIDI is a 5mA current loop, not 5V. The circuits given in the MIDI manual are examples only, although the spec authors concede that they've never considered operating a MIDI interface at anything other than 5V (I've already had that discussion with them...). To be honest, considering the OP was inte...
by Neil
Fri Feb 21, 2014 12:19 pm
Forum: Graphics, sound and multimedia
Topic: Using the Pi to build a hardware synthesizer
Replies: 12
Views: 7584

Re: Using the Pi to build a hardware synthesizer

Interesting. I've been looking at getting an FM soft synth running on the GPU. I wonder how much interest there would be in it?
Neil
by Neil
Fri Dec 13, 2013 12:03 pm
Forum: Off topic discussion
Topic: they finally recognised Delia..
Replies: 10
Views: 4109

Re: they finally recognised Delia..

Someone posted a short video from that concert on Youtube: http://www.youtube.com/watch?v=uCZHdFZPcPM

The memory of hearing the Thunderbirds march live stills gives me tingles!!

Neil
by Neil
Fri Dec 06, 2013 2:31 pm
Forum: Off topic discussion
Topic: they finally recognised Delia..
Replies: 10
Views: 4109

Re: they finally recognised Delia..

Don't forget Barry Gray http://en.wikipedia.org/wiki/Barry_Gray I had the pleasure of living in his studios at Red Gables, Esher, Surrey in the late 70's, unfortunately it was after he moved out :( A few years ago I had the fortune to get tickets for a concert at the South Bank. London Philharmonic...
by Neil
Fri Dec 06, 2013 2:26 pm
Forum: Off topic discussion
Topic: they finally recognised Delia..
Replies: 10
Views: 4109

Re: they finally recognised Delia..

Delia was far more than a "technician", a composer in her own right. Sadly now RIP :( "Time To Go" makes for an awesome ringtone.....just set it really loud and when it goes off you know the seconds are counting down before major embarrassment!! Neil I found an mp3 version and omxplayer was happy t...
by Neil
Thu Nov 28, 2013 10:30 am
Forum: Other programming languages
Topic: Julia
Replies: 1
Views: 2429

Julia

Yet another maths language:

http://julialang.org/

Comparative performance looks good (see figure, summary: about as fast as compiled Fortran).

Neil
by Neil
Tue Nov 26, 2013 5:31 pm
Forum: Off topic discussion
Topic: they finally recognised Delia..
Replies: 10
Views: 4109

Re: they finally recognised Delia..

And if you like the work of Delia, be sure to look up Daphne Oram as well.

Neil
by Neil
Tue Nov 26, 2013 5:30 pm
Forum: Off topic discussion
Topic: they finally recognised Delia..
Replies: 10
Views: 4109

Re: they finally recognised Delia..

Delia was far more than a "technician", a composer in her own right. Sadly now RIP :(

"Time To Go" makes for an awesome ringtone.....just set it really loud and when it goes off you know the seconds are counting down before major embarrassment!!

Neil
by Neil
Thu Oct 03, 2013 12:08 pm
Forum: Graphics, sound and multimedia
Topic: Gain of PWM audio
Replies: 5
Views: 1106

Re: Gain of PWM audio

Possibly, I don't know much about the Alsa driver. Once the PWM pin is pegged at 0 or 1 it isn't going any further!

Neil
by Neil
Thu Oct 03, 2013 12:04 pm
Forum: Graphics, sound and multimedia
Topic: Gain of PWM audio
Replies: 5
Views: 1106

Re: Gain of PWM audio

And your doubt is correct - there is no analogue amplifier on the Raspberry Pi board.

Neil
by Neil
Thu Oct 03, 2013 11:55 am
Forum: Graphics, sound and multimedia
Topic: Gain of PWM audio
Replies: 5
Views: 1106

Re: Gain of PWM audio

Depends on what the reference level is.
You need to know what '0' means. In digital audio you typically define some physical voltage as "0dBFS", and then everything is relative to that.
by Neil
Wed May 08, 2013 5:04 am
Forum: Camera board
Topic: Camera Interface Specs
Replies: 353
Views: 84988

Re: Camera Interface Specs

atto wrote:The missing of a reasonable fast interface into and out of the device may be the reason for its reduced success.
You have an amusing definition of success....

Neil
by Neil
Wed Feb 06, 2013 11:08 am
Forum: User groups and events
Topic: RasPi lecture, 21st Feb, Cambridge
Replies: 1
Views: 842

RasPi lecture, 21st Feb, Cambridge

Rob Mullins will be giving a talk about the Raspberry Pi on 21st February at Churchill College in an evening lecture being hosted by the Cambridge IET. You can register for this FREE event at the link below:

http://www.theiet.org/events/2013/172129.cfm
by Neil
Thu Nov 08, 2012 3:59 pm
Forum: Bare metal, Assembly language
Topic: Simple printf and sprintf
Replies: 5
Views: 3729

Re: Simple printf and sprintf

For a full-featured yet small code size (s)printf library I can recommend format. Doesn't do any floating point yet, as I haven't yet had time to work on that part.
by Neil
Fri Oct 12, 2012 10:52 am
Forum: C/C++
Topic: GPU Processing API
Replies: 124
Views: 45782

Re: GPU Processing API

No ARC hardware. Just the Metaware toolchain. ARC bought MetaWare later on.

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