Am 27.04.2013 21:08, schrieb Michael Hartje: > dear list readers, > > I would like to briefly report on the operation RaspberryPi. > > Basically, the system with 460 BogoMIPS is just barely suitable in > normal operation, to operate the Codec2 and FDMDV. Without the graphics, > RaspberryPi can provide sufficient power for that. Shure - it has a very efficient float-point performance! > > We need hardware: > USB Hub - $ 5 > 2 USB sound cards (for example CM108 for about $ 4) > RaspberryPi (RAM 500 MB) well... It has 512 MB (Model B) or 256 MB (Model A) You can setup the memory usage (memory split) between GPU and CPU in following steps 256/128/64/32/16/8 MB for GPU (rest of it goes to CPU) Default is 64 MB... But when changing to 8 MB, you have 504 MB RAM for the CPU... > > circuit:TX / RX - Sound Card hw: 1 - Raspi - Sound Card hw: 2 - micro / > speaker > > The RaspberryPI is configured > 1. with > sudo raspi-config > allow an overclock to 900 MHz and reboot. The computer then adjusts > dynamically the clock frequency during runtime when heavy loaded up to > 900 MHz . Instead of this, us the latest firmware update. It wil enable a ''turbo mode'' (equal to latest x86-64 - CPUs!) that will automatically overclock if possible to up to 1 GHz without loss of warranty (manual overclocking voids it!) > 2. Install all needed software with apt-get install > 3. Freedv with graphics can be compiled and can be executed. (Do not > hesitate to ask for my binary package)Unfortunately, the performance of > the CPU is not sufficient to allow for graphics and signal processing. Maybe, when having a console-interface using ncurses, you're stil able to have some GUI... Even oldscool, but fine... The analog Output will be fine for an NTSC/PAL - resoluton GUI... > > But: > > RaspberryPI as a modem / Demodem and codec > We use the files in the compiled directory codec2-dev > with two scripts for send and receive (see below) > We can call the scripts or cancel when switching a bit on the GPIO port. Like a simple on/off trigger... Easierst may be connection one of it's +5V pins with one of the GND-pins... > > The RaspberryPI has a 90 - 95% CPU load and is able to work as expected. > > The GPIO switching could be done with a Python script (eg with > raspberry-gpio-python - http://code.google.com/p/raspberry-gpio-python) > calling an killing the both scripts. nice > > It was done on this Rasbian-OS: > Linux raspberrypi 3.6.11+ #371 PREEMPT Thu Feb 7 16:31:35 GMT 2013 armv6l > > receive-1600.sh > -----8<------------ > #!/bin/bash > # by Michael, dk5hh at darc.de > #audio-input > AI="hw:1" > AO="hw:2" > # > echo Audio von $AI demod - fec1300+300 c2-1300 play auf $AO > D=/home/pi/Scratch/fdmdv2/src/codec2-dev/src > arecord -Dplug$AI -r 48000 -t raw -f S16_LE -c 1 - \ > | sox -t raw -r 48000 -e signed-integer -c1 -b 16 - \ > -t raw -r 8000 -e signed-integer -c1 -b 16 - | \ > $D/fdmdv_demod - - 16 \ > $D/fec_dec - - 1600 | \ > $D/c2dec 1300 - - | \ > aplay -Dplug$AO --rate 48k -t raw -r 8000 -f S16_LE -c 1 - > -----8<------------ > > transmit-1600.sh > -----8<------------ > #!/bin/bash > # by Michael, dk5hh at darc.de > #audio-input > AI="hw:2" > AO="hw:1" > # > echo Micro von $AI C2enc-1300 FEC-1300+300 mod_1600 play auf $AO > D=/home/pi/Scratch/fdmdv2/src/codec2-dev/src > arecord -Dplug$AI -r 48000 -t raw -f S16_LE -c 1 - \ > | sox -t raw -r 48000 -e signed-integer -c1 -b 16 - \ > -t raw -r 8000 -e signed-integer -c1 -b 16 - | \ > $D/c2enc 1300 - - | \ > $D/fec_enc - - 1600 | \ > $D/fdmdv_mod - - 16 \ > aplay -Dplug$AO --rate 48k -t raw -r 8000 -f S16_LE -c 1 - > -----8<------------ > > scripts for 1400 Bit (freedv mode 0.91) can be easily obtained. Cool... Maybe the 1200 bit/s mode and the 2400 bit/s mode are quite more interesting... As 2400 bit/s was the first reference, and 1200 bit/s is the actual narrowest banwith specified for Codec2. > > Michael, DK5HH > > ------------------------------------------------------------------------------ > Try New Relic Now & We'll Send You this Cool Shirt > New Relic is the only SaaS-based application performance monitoring service > that delivers powerful full stack analytics. Optimize and monitor your > browser, app, & servers with just a few lines of code. Try New Relic > and get this awesome Nerd Life shirt! http://p.sf.net/sfu/newrelic_d2d_apr > _______________________________________________ > Freetel-codec2 mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 > > > --- > avast! Antivirus: Eingehende Nachricht sauber. > Virus-Datenbank (VPS): 130427-0, 27.04.2013 > Getestet um: 27.04.2013 23:56:51 > avast! - copyright (c) 1988-2013 AVAST Software. > http://www.avast.com > > >
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