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by Avoncliff
Mon Mar 02, 2015 11:02 am
Forum: Bare metal, Assembly language
Topic: Bare metal for real time sound?
Replies: 9
Views: 3361

Re: Bare metal for real time sound?

How real is real time?
Sound travels though the air @ 1msec per foot ( in round numbers).
So a 10 msec delay is much like being 10feet from the sound source.
At a 1msec delay, with headphones, the sound will be heard earlier than a guitarist would hear it live.
by Avoncliff
Fri Feb 27, 2015 2:23 pm
Forum: Bare metal, Assembly language
Topic: Baremetal Forth?
Replies: 14
Views: 5783

Re: Baremetal Forth?

rst Thanks for looking, as I said the performance hit was not the most urgent thing for me to look at. I could not really use it at all as free standing with out the SD card reading that is now included. And there is a lot more to investigate to get a usable forth system. I will follow up on your su...
by Avoncliff
Thu Feb 26, 2015 11:52 pm
Forum: Bare metal, Assembly language
Topic: Baremetal Forth?
Replies: 14
Views: 5783

Re: Baremetal Forth?

I have updated my version of pijForthos at https://github.com/Avoncliff/pijFORTHos/tree/SD. I have added a SD library borrowed from John Cronin's rpi-boot project. So now the Jonesforth now auto loads the jonesforth.f file to complete the install. And you can load other forth code with LOAD file. Th...
by Avoncliff
Tue Feb 24, 2015 11:06 am
Forum: Bare metal, Assembly language
Topic: Please help me with Yagarto
Replies: 1
Views: 675

Re: Please help me with Yagarto

I do not use Yagarto, or Windows, and I guess not many others here do, so I will try and give general advice only. GCC is normally run from the command line, and by using a makefile. The Yagarto web site suggests it can be used with eclipse, but this is a very big tool to crack a simple task and I w...
by Avoncliff
Fri Feb 20, 2015 6:25 pm
Forum: Bare metal, Assembly language
Topic: Introducing USPi - A bare metal USB driver written in C
Replies: 73
Views: 21914

Re: Introducing USPi - A bare metal USB driver written in C

This is caused by the implementation of the frame scheduler. It's not easy to change this
I thought that might be the case.
When I get round to a pi2 I could think about multi core, but no rush.
David
by Avoncliff
Thu Feb 19, 2015 10:17 pm
Forum: Bare metal, Assembly language
Topic: Introducing USPi - A bare metal USB driver written in C
Replies: 73
Views: 21914

Re: Introducing USPi - A bare metal USB driver written in C

I am also very impressed with your work, thanks. Have you done any work on the speed. I am finding it slows down the code I am linking it to dramatically. I can look at rewriting critical bits in assembler but the slow down looks larger than this. I have no understanding of the USB stack but is it l...
by Avoncliff
Thu Feb 19, 2015 8:49 pm
Forum: Bare metal, Assembly language
Topic: Baremetal Forth?
Replies: 14
Views: 5783

Re: Baremetal Forth?

I have been hacking on pijForthos https://github.com/organix/pijFORTHos. My first attempt added a frame buffer, my second go added the lib files from https://github.com/rsta2/uspi. Find it here https://github.com/Avoncliff/pijFORTHos My thanks to both of these projects. This version allows keyboard ...
by Avoncliff
Tue Feb 03, 2015 10:41 pm
Forum: Bare metal, Assembly language
Topic: Baking_PI_Input01:????
Replies: 6
Views: 1109

Re: Baking_PI_Input01:????

I have just compiled this lesson, and I can confirm it needs a build directory that does not exist. I just added an empty directory and it compiles fine. I also have problems getting response from the keyboard, but Alex does say it does not work with all keyboards. So I am looking for a keyboard tha...
by Avoncliff
Sun Feb 01, 2015 10:48 am
Forum: Bare metal, Assembly language
Topic: FreeRTOS Sucessfully Ported
Replies: 47
Views: 61189

Re: FreeRTOS Sucessfully Ported

Hi prabhakar This was answered mar15th last year. The raspberry has a slightly odd boot process in that the GPU boots first and then starts the ARM. To produce a boot SD you need to format the card to FAT32 and install the bootcode.bin and start.elf files for the GPU, and then add your new kernel.im...
by Avoncliff
Sun Feb 16, 2014 11:07 pm
Forum: Automation, sensing and robotics
Topic: Source code to w1-therm?
Replies: 41
Views: 34001

Re: Source code to w1-therm?

The best place to post it is to the kernel mailing list, also not easy but it is all documented and a real feeling of satisfaction when Greg accepts the patch for the next Linux version.
by Avoncliff
Thu Jan 23, 2014 8:17 pm
Forum: Advanced users
Topic: Arm Forth Project
Replies: 29
Views: 8961

Re: Arm Forth Project

Hi If you are referring to the sudo cp -r /lib/terminfo/* /usr/share/terminfo Yes that is done. Still same report, note I am running this headless via ssh. The older pi it runs, also via ssh, but not for long..... If I run extend it returns no errors and creates a a4 version. but that gives [email protected]...
by Avoncliff
Thu Jan 23, 2014 12:22 pm
Forum: Advanced users
Topic: Arm Forth Project
Replies: 29
Views: 8961

Re: Arm Forth Project

Thanks. I have two Raspberrys on the older one it runs, not tested very far but I could compile a word. On the newer unit running the latest raspian and kernel 3.10.27+ I get: [email protected] ~/forth/a4 $ strace ./a4k execve("./a4k", ["./a4k"], [/* 16 vars */] <unfinished ...> +++ killed by SIGKILL +...
by Avoncliff
Wed Jan 22, 2014 7:40 pm
Forum: Advanced users
Topic: Arm Forth Project
Replies: 29
Views: 8961

Re: Arm Forth Project

I think I used
CPU = arm1176jzf-s
ARCH = armv6zk
But whether more of the recommended should be used I do not know
-Ofast -mfpu=vfp -mfloat-abi=hard -march=armv6zk -mtune=arm1176jzf-s
by Avoncliff
Mon Jan 20, 2014 4:27 pm
Forum: Advanced users
Topic: Arm Forth Project
Replies: 29
Views: 8961

Re: Arm Forth Project

I think the makefile cpu = cortex-A8 is wrong. the BCM2835 is not cortex. I have tried other options but then get the error: compile.s: Assembler messages: compile.s:543: Error: selected processor does not support ARM mode `movw r7,#2' compile.s:544: Error: selected processor does not support ARM mo...
by Avoncliff
Mon Jan 20, 2014 2:40 pm
Forum: Advanced users
Topic: Arm Forth Project
Replies: 29
Views: 8961

Re: Arm Forth Project

It gets worse, I just tried this on a spare pi that I had just rebuilt the kernel, and it does not run at all. $./a4k killed $ I tried strace on old pi. but forum does not want to attach it. This is end of file open("src/a4.f", O_RDONLY) = 3 lseek(3, 0, SEEK_END) = 5092 mmap2(NULL, 5092, PROT_READ|P...
by Avoncliff
Sat Jan 18, 2014 10:35 pm
Forum: Advanced users
Topic: Arm Forth Project
Replies: 29
Views: 8961

Re: Arm Forth Project

Yes set it to armv6
problem is with ;
it gives the error on completing a word define
by Avoncliff
Fri Jan 17, 2014 9:50 pm
Forum: Advanced users
Topic: Arm Forth Project
Replies: 29
Views: 8961

Re: Arm Forth Project

Just to let you know compile is fine.
At the moment loading a4.f bombs at
"fload src/ext/comment.f Illegal instruction"
Will look at why later....
by Avoncliff
Thu Jan 16, 2014 11:26 pm
Forum: Advanced users
Topic: Pi as audio player, Android as remote - misc questions
Replies: 3
Views: 2457

Re: Pi as audio player, Android as remote - misc questions

I am using mpd, and connecting controlling from android with mpdroid.
But I am not doing some of the options you want.
by Avoncliff
Thu Jan 16, 2014 11:21 pm
Forum: Advanced users
Topic: Arm Forth Project
Replies: 29
Views: 8961

Re: Arm Forth Project

+1
I am sure I still have that game I wrote in forth 30+years ago somewhere.

What does it look like at present, an assembler source file?

David
by Avoncliff
Mon Dec 16, 2013 11:17 am
Forum: General discussion
Topic: Instant power off?
Replies: 8
Views: 1939

Re: Instant power off?

If it is a media centre why would it be writing anyway?
Well log files are one reason, but if all logging is turned off what other writing would be involved?

And on a purely practical note, if the only damage is to files on the SD card a backup SD card gets you going again very quickly.
by Avoncliff
Mon Apr 22, 2013 10:22 pm
Forum: Graphics, sound and multimedia
Topic: usb dac audio with mpd
Replies: 1
Views: 2151

Re: usb dac audio with mpd

I also had problems setting this up, I think the change that got it working was mpd.conf audio_output { type "alsa" name "USB DAC" device "front:DAC" # optional format "44100:16:2" # optional mixer_device "default" # optional mixer_control "PCM" # optional mixer_index "0" # optional } And then resta...
by Avoncliff
Mon Mar 11, 2013 9:25 pm
Forum: General discussion
Topic: RPi doesn't start with external HDD
Replies: 17
Views: 2708

Re: RPi doesn't start with external HDD

If it works OK plugging it in later, and you have external power, then that should rule out power problems. You could check the volts on the Raspberry during boot just to check there is no dip below say 4.9v, just to be sure. After that it sounds like a problem with the low level boot loader, which ...
by Avoncliff
Sun Mar 10, 2013 11:39 am
Forum: General discussion
Topic: web browser text "turn on" to send GPIO?
Replies: 2
Views: 603

Re: web browser text "turn on" to send GPIO?

What I have done to control GPIO from a web browser is use CGI scripts.
I installed lighttpd, created a web page on the raspberry with buttons for the things I want to control and now from my phone I just click buttons to control the hi-fi.
by Avoncliff
Mon Sep 24, 2012 8:51 pm
Forum: Graphics, sound and multimedia
Topic: Crackly audio through 3.5mm jack
Replies: 95
Views: 43097

Re: Crackly audio through 3.5mm jack

A quick vote of thanks to Dom and all others who have worked on this.
I am now happily listening to Ben Webster through my Quad system, via mpd on the pi controlled from the android phone.
There is a great improvement in sound quality from last time I tried this.
by Avoncliff
Wed Jul 25, 2012 11:04 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: kernel patch for Dallas 1-wire interface
Replies: 227
Views: 157130

Re: kernel patch for Dallas 1-wire interface

I have failed to add this 1wire to the raspbian kernel, has anyone done this successfully? I got the kernel source from https://github.com/raspberrypi/linux.git and built it OK. I then tried adding Frank's patch and building 1-wire as a module, this built and installed OK but will not load. I note t...

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