Raspberry Pi Forums

PeterO

Hello, did you mean a mapping like this? varying vec2 tcoord; uniform sampler2D tex; void main(void) { float val = texture2D(tex,tcoord).x; vec3 res = vec3( val*25.0, val*49.0, val*3.0+0.75 ); res = fract(res); gl_FragColor = vec4(res, 0.5) ; } Regards Yggdrasil Thanks, but it's not quite what I'm ...

PeterO

The waterfall display in my panadapter currently is in monochrome.
http://www.youtube.com/watch?v=0IZxzm4R1bo

I'm trying to find a "good" algorithm for mapping the 256 values of grey into colours but so far I've had little success,

PeterO
G0DZB

PeterO

What happens if your receiver misses a dot (or two)? How can you resync your signal? There is/should be an inter-letter gap of three dots length between each letter, that is sufficient to resync at the start of the next letter. It's enough for the human brain to detect the start of each letter. Pet...

PeterO

Gswg wrote:Nothing planned Peter.

Sorry.

Shame, because from what I see someone needs to kick the I2S developers to sort out I2S input to be supported out of the box without needing to build custom kernels

PeterO

PeterO

And plans for a ADC ?
PeterO

PeterO

Since the normal tools like find fail to meet your requirements due to the large number of files involved, . I can't find any mention of a maximum number of files that find can deal with. I don't think it needs to keep a record of each file so memory won't be a limit on the number of file names it ...

PeterO

I just noticed lots of these in /var/log/messages May 22 20:51:38 pi1 kernel: [15182.005314] retire_capture_urb: 2 callbacks suppressed May 22 20:52:04 pi1 kernel: [15207.603374] retire_capture_urb: 1 callbacks suppressed May 22 20:52:11 pi1 kernel: [15214.984398] retire_capture_urb: 2 callbacks sup...

PeterO

AndyD wrote: I used the venerable book The C Programming Language by Kernighan and RItchie.

But did you use the 1st Edition ?

PeterO

PeterO

utube of latest version http://youtu.be/0IZxzm4R1bo

PeterO

If you have access to another Linux machine it is quite easy. I'm not going to type detailed instructions until you come back and say you have another linux machine, but in outline..... First off make a new filesystem on the usb stick. Mount the root partition of the sdcard and the usbstick and use ...

PeterO

It's not really a multicast issue. Whatever device is the server will allocate a new socket for each client making a connection request on its listening socket. The server just needs to keep track of which sockets are active and service them in a round-robin (or whatever) manner. It's easy to do in...

PeterO

I'de start by reading up on multicast networking:

http://en.wikipedia.org/wiki/IP_multicast

PeterO

PeterO

Graticule added to graph, and improved spectum calculation that uses all of the available I/Q samples rather than throwing 3/4 of them away. Result is better S/N due to some averaging over 4 transforms. Still some work to do in that area including trying overlapping transforms. Next is some axis lab...

PeterO

The QPU's were designed by some bloke here called Upton, E. So you can blame him on the wackiness. I think they were indeed designed for high performance, low die area (and hence low power consumption) but this Upton bloke knows much more about it that I do. All I know is that people avoid them lik...

PeterO

I wondered if you have a callsign, now I think I know what FFT and waterfalls are for. Hopefully psk and RTTY will be supported. :-) Ken M0GBP Ken, I've got no plans at the monent to do anything other than a panadapter. It still needs to have a graticule and axis labels, then USB interface to radio...

PeterO

http://www.peteronion.org.uk/PiPics/pipan2.mpeg

Real time display using 96kHz sampling from a USB soundcard... And not even overclocked !

PeterO
G0DZB

PeterO

Actually, having run rpi-update last evening I can now successfully capture 96kHz audio from my USB soundcard so there is no need to mess about with the broken I2S sub-sysytem.
PeterO

PeterO

I just updated and now I can record at 96kHz from my USB soundcard

Previously it just disconnected when I tried

PeterO

PeterO

My plan was to drive this display from a 96kHz I2S audio ADC, but now that I've looked at I2S suport I see the state of the I2S drivers is so poor that the whole thing is now looking unworkable. Why people think it is acceptable to produce I2S hardware for which users have to build custom kernels is...

PeterO

You have to patch the kernel anyway since none of the included board drivers supports audio input. How long before they are included in the official kernel tree ? Wolfson provides a bunch of patches that should easily merge with the current kernel (and therefore with your kernel, too) ( http://down...

PeterO

Depends on what you want to do. Thanks for reply Florian, I want to do 96kHz or 192kHz stereo capture, which means 3 of the 4 cards you listed are not appropriate, and from what I gather the Wolfson only works on a specially cobbled together kernel that they produced and is not being kept upto date...

PeterO

apt-cache search alsamixer alsa-utils - Utilities for configuring and using ALSA alsamixergui - graphical soundcard mixer for ALSA soundcard driver cairo-dock-alsamixer-plug-in - Cairo-dock - Alsamixer plug-in gmerlin - multiformat media player gnome-alsamixer - ALSA sound mixer for GNOME libasound2...

PeterO

Is there a "HOWTO get started with i2S" anywhere ? I can't see the point of reading 22 pages, most of which is many months old and probably contains of out of date information.

PeterO
G0DZB

PeterO

I'm looking for a 96kHz( or 192kHz) 16bit,stereo ADC for getting the i/Q signal from a radio into a PI. I've found this http://robosavvy.com/store/product_info.php/products_id/1384 which looks like it will do the job (I'm electronics competent :-) ) but I can't find any references to it working with...

PeterO

And now with a waterfall dispaly as well

http://www.peteronion.org.uk/PiPics/pipan1.mpeg

Search found 5926 matches

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