Cirrus Logic Sound Cards & Media Devices Drivers
Cirrus Logic Sound Cards & Media Devices Driver Download
Cirrus Logic Sound Cards & Media Devices Driver Windows 7

There is more green space and trees around me where I am now, with many more garden birds, though no sparrows¹, and occasionally some tawny owls in the night.

http://www.richardmudhar.com/blog/wp-content/uploads/2018/02/tawny_owls_somerset_170828_0125_ed.mp3

An important sound card characteristic is polyphony, which refers to its ability to process and output multiple independent voices or sounds simultaneously.These distinct channels are seen as the number of audio outputs, which may correspond to a speaker configuration such as 2.0 (stereo), 2.1 (stereo and sub woofer), 5.1 (surround), or other configuration. Cirrus Logic’s audio card is the jack of all trades sound card with five separate possible connections: – a 3.5 mm 4-pole jack for headsets and headphones with speaker support at the same time – a 3.5 mm stereo line input for high-end audio recording – a 3.5 mm stereo line output for connection with active speakers or amplifiers. Cirrus Logic Audio Card 2015 Update. By jwhyte in Cirrus Logic Audio Card on Jan 16, 2015 “Introduction to the Cirrus Logic Audio Card With the launch of the Model B+ there was one significant, yet highly appreciated change which meant the existing audio card with the P5 pogo pins was no more.

Tawny owls, recorded ME66 handheld

So thoughts turn to a garden recording gizmo again. I have enough power, and a network connection to a shed, a oddly wind-sheltered location and many trees nearby. For short term recordings in the field I am still in favour of the timed field recorder approach, but for the garden where I have power and data the Pi still scores. You don’t have to fiddle with it, it’s entirely remote controlled. Many years ago I had a PC in the garage which was the music server, I used a piece of software called loop recorder on that. This cat fight is one of my favourite urban recordings from that time.

http://www.richardmudhar.com/sounds/audio/071020_cats.mp3

although I was really trying to record a hedge full of sparrows. A loop recorder lets you go back and catch things like that, and the microphone would be much closer to the area where the owls are.

So I thought I’d revisit this Cirrus Logic audio card, particularly as a case for a Pi with this mounted was being sold off cheap for £5

The Cirrus is the only audio card for the Raspberry Pi that lets you record sound with it, as opposed to the legion of DAC cards for the Pi. You can, of course, use a USB sound card instead, though that precludes using a Model A if you want to use wifi and have the lowest power.

The good news is that a hero hacker, Matthias Reichl, has sorted out the drivers, it’s now a RPI-update rather than patching kernels and esoteric crap.

The bad news is that the manufacturer discontinued the card 🙁 Having said that, it still seems to be available for about £60 if you work hard enough, GIYF. That’s dear – a Behringer UCA202 is a good Pi compatible USB sound card for about £24, line level input. The Cirrus Logic card offers a bit more sensitivity and on board mic bias.

Installation process

It’s not absolutely futz-free, though it’s far better than it used to be. I’ve never managed to blow a Raspberry Pi board, so I have a fine collection of old boards from my Pi history, the very first one is still in service collecting sensor data.

For this job I will select a Raspberry Pi B+ with Ethernet, the first model with the 40-pin GPIO and the HAT physical format, because that’s what the Cirrus wants. I could use an A+, but I want Ethernet, because paradoxically trunking WiFi to the shed with some patch antennas works fine but doesn’t give me WiFi at the shed, and I want lots of USB connectors spare, because I will probably be recording using real spinning HDD, because – well SD cards burn out whereas spinning metal seems to last. Plus the latter is fast, although recording audio really shouldn’t be an I/O challenge even for SD these days.

Get new raspi-stretch lite, load without card attached
works, enable ssh, enable key, test key login
sudo apt-get update, sudo apt-get upgrade
Now visit http://www.horus.com/~hias/cirrus-driver.html and do as the man says
sudo nano /boot/config.txt, can the internal audio and add the line as instructed
sudo nano /etc/modprobe.d/cirrus.conf, add line
wget http://www.horus.com/~hias/tmp/cirrus/cirrus-ng-scripts.tgz, make bin directory, do it
sudo shutdown -h now, wait for green blinkenlights, pull power and attach card
Restart Pi, log in
execute the bin/Record_from_Linein_Micbias.sh file, which terminated silently

Now I run alsamixer, knowing that I have killed off the internal sound card. I’m only interested in record, if I wanted just play I’d go buy myself a cheap DAC HAT and save myself a ton of trouble. Don’t even think of using the F4 button to switch to Capture, use the arrow key to get to the relevant section and then the tab key to select in section, because alsamixer is ratty and will crash if you press F4. You get this

but in fact what you actually want is all the way to the right, so make with the right arrow key, past all that equaliser crap

The implication is that I am looking at IN3L and IN3R, because IN1L,R and IN2 L,R are set to 0, and hopefully nobody’s tossing anything in on DIG 1,2,3, although in a perfect world it would be nice to see them set to 0 too. Nice that the noise generator is set to 0, though the noise gate is worrying, apparently that means

Noise Gate Threshold: [dB Gain: -90.00]

What that means in real life, well, your guess is as good as mine, but I’ll leave it well alone for now.

To get to record from the card you need to know what you’re recording from, so I set 1kHz tone going in and do this

It’s either RPiCirrus or it’s RPi-Cirrus, I’ll save you the experimentation, it’s the former

when I FTP the result off the Pi and look at it I get

Which looks OK – there’s a slight phase difference and the usual DC bump at the start – try and start recording at least a quarter second of deadspace to let that die off.

So it does basically work, with a stock Pi with a minimum of fiddling about. Win.

Adjusting levels

The nominal gain of IN3 is 8dB (displayed as 16). If I crank it all the way I can get up to 31dB, displayed as 100. So I will try that on IN3R.

Cirruslogic Sound Cards & Media Devices Driver

This confirms IN3 is the input I am dealing with. I wasn’t really able to convince myself the mic bias ever came on. I could have had this information easier if I’d used the Source, because in the file rpi-cirrus-functions.sh is the section

but where’s the fun in that, eh? You can find the original of the scripts on Github. Apparently Matthias’ sterling work is all to do with LibreELEC which is designed to be just enough OS to run KODI, so the fact that recording is looked at at all is impressive, since you don’t normally record anything with a media server.

buffer overruns

Everyone and his dog starts off recording to the same SD card that the OS is on, and you get buffer overruns. There are all sorts of reasons why you shouldn’t record audio to the OS SD card, but overruns seems to be the obvious one. This thread seems to confirm this, the OS is busy with the SD card at times so it can’t write your audio.

So I mounted a USB stick. You get to run as sudo because you’re writing to a device, there’s probably a way to fix that but for now I’ll run with it

Nice try but no cigar. How about using FLAC? It reduces the IO, but it also offers the possibility of using jstsch’s massive interpass buffer trick.

Hmm, looks OK² without the buffer on the USB drive for 5 mins (set to 48k to be the same as previous ones where it barfed). Flac gets the sudo this time because it has the job of writing to the USB stick.

input buffer trick (onto the normal disk)

which seemed to go OK for the 5 sec duration, so if it turns out I need it I have the command line. It’s a lot of faff to go to if it’s not needed.

Analogue issues

There are three problems with using this for an electret mike:

The mic bias ~~doesn’t work~~
sensitivity is low, it is a line input after all. OTOH I can boost it by 23dB

Cirruslogic Sound Cards & Media Devices Driver