Go to advanced search

by chuckkh
Wed Aug 21, 2019 9:41 pm
Forum: Graphics, sound and multimedia
Topic: Pi4 onboard sound - as bad as ever?
Replies: 2
Views: 391

Pi4 onboard sound - as bad as ever?

Hi there. Just curious. Is the onboard sound on the Pi 4 as bad as previous ones? I don't see audio mentioned in any reviews, so I'm guessing it's the same. Or is it even still there? I bought 3 when it was new and excitedly searched out and found an acceptable ADC/DAC chip, on the Teensy Audio Adap...
by chuckkh
Thu Jun 16, 2016 6:56 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: I2S Success (at last) !
Replies: 111
Views: 55125

Re: I2S Success (at last) !

Right, I know. But, with the codec putting out a verified 44100 set of clocks and RPi playing a 44100 sr wav file, something is resampled or misinterpreted. With RPi as timing master, it still plays too fast. If I'm manually configuring the codec with i2c, ALSA doesn't know how the codec ia configur...
by chuckkh
Thu Jun 16, 2016 9:59 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: I2S Success (at last) !
Replies: 111
Views: 55125

Re: I2S Success (at last) !

Hi all, I would like to create a sound card using the sgtl5000 (teensy audio board) for Raspberry 2. When I wire the power and I2C, i2cdetect don't see anything. I miss something ? Thanks for your answer Phi The datasheet for the SGTL5000 explains that, until it has a "master clock" input, it is ef...
by chuckkh
Wed Jun 15, 2016 3:40 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: I2S Success (at last) !
Replies: 111
Views: 55125

Re: I2S Success (at last) !

Incidentally, I tried to use my codec's ALSA driver, sgtl5000, according to Plugh's instructions, but the codec is never listed in /sys/kernel/debug/asoc/codecs. Another aspect about which I can find no info online. Any idea how to get my codec listed there. This would be thrilling!

Chuckk
by chuckkh
Wed Jun 15, 2016 3:37 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: I2S Success (at last) !
Replies: 111
Views: 55125

Re: I2S Success (at last) !

1/3 faster looks as if you are sending 24 bits instead of 32 bits /Audio sample and Channel. I thought of that, too, but it's not so. If I could set RPi I2S to send at 8000 SPS, I could verify the output with my Arduino logic analyzer, but I have no control over the output sample rate. Changing Aud...
by chuckkh
Wed Jun 15, 2016 3:22 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Non-ALSA I2S, user space DMA
Replies: 0
Views: 413

Non-ALSA I2S, user space DMA

I've been trying for months to get my RPi3 to send correct I2S to my audio codec (using Raspbian, but planning to switch to Arch with Xenomai). The various simple card loaders play at the wrong speed and I'm out of ideas as to why. Using a modified I2S test by Simon Hughes, I can synthesize a sine w...
by chuckkh
Fri Jun 10, 2016 3:59 pm
Forum: Linux Kernel
Topic: RT/Xenomai with short startup time?
Replies: 0
Views: 2413

RT/Xenomai with short startup time?

Hi. I'm trying to make a musical instrument for stage use. From what I'm reading, Xenomai appears to be the way to go for really low latency. What I'm wondering is how does it affect startup time? Does it make it longer? My application will consist of a one-time I2C codec setup, GPIO polling (maybe ...
by chuckkh
Wed Jun 08, 2016 7:13 pm
Forum: Bare metal, Assembly language
Topic: Beginner question - porting software
Replies: 0
Views: 705

Beginner question - porting software

Hi! I'm a musician interested in programming instruments and such, and I'm drawn to bare metal Pi for the fast booting and hopefully low latency. I need something for professional performance use, so maybe I'm being optimistic hoping for a $35 solution (well, twice that in Romania, but still cheap),...
by chuckkh
Tue Jun 07, 2016 11:27 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: I2S Success (at last) !
Replies: 111
Views: 55125

Re: I2S Success (at last) !

I've been working on this in every spare second for almost 2 months. I can manually set up the codec, no problem. i even managed to modify some testing code from Simon Hughes to match the BCM's I2S format with the codec's I2S format, and to synthesize a saw wave that plays at the right frequency and...
by chuckkh
Tue May 17, 2016 6:25 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Please help! I2S wrong speed
Replies: 5
Views: 3814

Re: Please help! I2S wrong speed

Hi. Thanks for looking it over. I'm sending a 9.6 MHz signal from the Pi to the codec, as an internal timer for the codec, and it is using its PLL to change that 9.6 MHz to something like 180 MHz, from which it derives 32x44100. The 9.6 MHz is not the bit clock and is not being sent to the Pi. I bou...
by chuckkh
Mon May 16, 2016 4:36 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: I2S interfacing with DSP4You DG
Replies: 8
Views: 3169

Re: I2S interfacing with DSP4You DG

Unbelievable. That is infuriating. I've wasted far more than 3 days with this piece of junk. Congrats on getting it to work!
Chuckk
by chuckkh
Tue May 10, 2016 9:34 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: I2S interfacing with DSP4You DG
Replies: 8
Views: 3169

Re: I2S interfacing with DSP4You DG

Yup, that's what the sheet says. What they call system clock is what I was calling bit clock, and it looks like it's fixed to 64 x the sampling frequency. You can probably change the sample rate and other settings, it mentions that but I didn't see instructions. By slave, I meant that the RPi can be...
by chuckkh
Tue May 10, 2016 6:31 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: STICKY: The I2S sound thread.
Replies: 926
Views: 480876

Re: The I2S sound thread.

Can you upload a clip of how the audio sounds? Well, upload, no, I can't, but I can link to one. There's a link in the first post in this thread: https://www.raspberrypi.org/forums/viewtopic.php?f=44&t=147516 Under "A 440 played fast on RPi codec:" I swear the crackling is periodic, and must be som...
by chuckkh
Tue May 10, 2016 8:00 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: STICKY: The I2S sound thread.
Replies: 926
Views: 480876

Re: The I2S sound thread.

My Pi is back in commission. I still have this problem, though, despite recompiling the I2S driver to only use 1 sample rate and 1 bit depth. I believe I'm giving up on it. I'm working on an embedded project and I don't need general-purpose; I don't want to watch videos or listen to my favorite song...
by chuckkh
Tue May 10, 2016 7:55 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: I2S interfacing with DSP4You DG
Replies: 8
Views: 3169

Re: I2S interfacing with DSP4You DG

I found it much simpler to use RPi as a timing slave, as long as your codec can do that. It's not hard to output a 9.6 MHz or lower clock from GPIO using wiringpi or pigpio. I can't find my code right now as my Pi is on the shelf, but you only have to set the mode of the one GPIO pin that can be use...
by chuckkh
Mon May 09, 2016 3:59 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: I2S interfacing with DSP4You DG
Replies: 8
Views: 3169

Re: I2S interfacing with DSP4You DG

Hi there. I'm not sure if this will solve your problem, but GPIO 18 input should be bit clock, not 24.576 MHz master clock. The master clock seems to be something that many audio chips need for their internal audio processing, but it is not considered part of the I2S standard; it doesn't need to be ...
by chuckkh
Mon May 09, 2016 3:16 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Please help! I2S wrong speed
Replies: 5
Views: 3814

Re: Please help! I2S wrong speed

I see that the Raspberry Pi 3 has some timing bugs, it does not do what it's supposed to do. I don't know, could this be related to I2S playing at the wrong speed? https://www.raspberrypi.org/forums/viewtopic.php?f=44&t=147142 https://github.com/RPi-Distro/repo/issues/22 https://www.raspberrypi.org/...
by chuckkh
Mon May 09, 2016 1:03 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Please help! I2S wrong speed
Replies: 5
Views: 3814

Re: Please help! I2S wrong speed

NB I play the same A440 wave file using internal audio and it plays at the correct speed and frequency! It is only wrong using I2S.
by chuckkh
Mon May 09, 2016 12:23 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Please help! I2S wrong speed
Replies: 5
Views: 3814

Please help! I2S wrong speed

Please help! I will include lots of detail so you can see that I've done my work, but what I'm really asking about is how to manually force ALSA SoC to play particular settings over I2S, without having it automatically detected by the soundcard driver! Down with automatic setup! We want manual! :) I...
by chuckkh
Mon May 09, 2016 8:57 am
Forum: Networking and servers
Topic: Ongoing Wifi misbehavior on RPi3
Replies: 8
Views: 2884

Re: Ongoing Wifi misbehavior on RPi3

Second most likely cause is a lousy power supply (or lousy USB-A to microUSB cable). I didn't want to believe it, but you just about nailed it. Not 100%, I mean, the power supply is OK, but, in my attempts to make I2S audio play at the right speed, I had hooked up an external crystal oscillator. So...
by chuckkh
Sun May 08, 2016 9:20 pm
Forum: Advanced users
Topic: Batteries as backup for unintentional unplugging
Replies: 5
Views: 1186

Batteries as backup for unintentional unplugging

How complicated does that sound? I want to use my Pi for stage performance, and while I'm OK with it being wired, I'm thinking of a way to be prepared for problems, considering how long it takes to boot. I see battery packs that can deliver enough current to keep the Pi from shutting down; but does ...
by chuckkh
Sat May 07, 2016 3:53 pm
Forum: Beginners
Topic: Reading SD Card with Windows
Replies: 17
Views: 173585

Re: Reading SD Card with Windows

I use DiskInternals free Linux reader http://www.diskinternals.com/linux-reader/ It allows you to view and copy from an ext3 formatted card, but not to write to it. There are others that allow writing too, but I've not tried those. See here for example http://www.howtoforge.com/access-linux-partiti...
by chuckkh
Fri May 06, 2016 4:27 pm
Forum: Networking and servers
Topic: Ongoing Wifi misbehavior on RPi3
Replies: 8
Views: 2884

Re: Ongoing Wifi misbehavior on RPi3

Open an LXTerminal window. What do you get from iwlist scan ? Can you see your SSID? Does your AP use WPA or WPA2 security? Or is it still using WEP? Or is it using something special like PEAP or LEAP? What channel does your AP run on? Have you defined your country code using sudo raspi-config (opt...
by chuckkh
Fri May 06, 2016 12:39 pm
Forum: Networking and servers
Topic: Ongoing Wifi misbehavior on RPi3
Replies: 8
Views: 2884

Re: Ongoing Wifi misbehavior on RPi3

For the record, I tried the setup cited here as a solution:
viewtopic.php?f=46&t=20290

And wifi still wouldn't connect.

-Chuckk
by chuckkh
Fri May 06, 2016 11:02 am
Forum: Networking and servers
Topic: Ongoing Wifi misbehavior on RPi3
Replies: 8
Views: 2884

Re: Ongoing Wifi misbehavior on RPi3

Now it's flipped! If I boot without ethernet plugged in, wifi connects; with ethernet plugged in, wifi does not connect. I removed ifplugd from my system because I DO NOT want this behavior; but at least it seems kind of motivated by some kind of logic, and I'm willing to live with it in order to us...

Go to advanced search