LAKKA RASPBERRY PI 3 SOUND VIA HDMI SOFTWARE

This is a limitation of the Broadcom BCM2835 in conjunction with the 19.2MHz crystal and there is nothing that can be done. That is not possible, since the frequency is not a multiple of 19.2MHz. For example, for 44.1KHz audio, the LR Clock must be running at precisely 44.1KHz. Since the only clock onboard the RPi is a 19.2MHz crystal, it should have trouble generating proper clocks for its I2S output. You see, in theory the RPi has a bit of a problem with its I2S output. For my distribution of choice, Archphile, it’s a piece of cake:

LAKKA RASPBERRY PI 3 SOUND VIA HDMI SOFTWARE

Now we have to configure the software for I2S output. Luckily, my Buffalo III has its own clock (of course it does!) and thus can be connected quite easily. This means in practice that your DAC will need to have its own on-board clock (or internal PLL / oscillator or whatever). You will probably notice that the RPi does not support MCLK output. This sounds way more interesting, right? Let’s try that!Īccording to several sources on the Net, this is the pin out:

Use the GPIO pins of the RPi to get direct I2S output.

Remember, the RPi is supposed to be a low cost solution. The problem is that they add another link to the audio chain, as well as increase the cost. XMOS, etc) as well as the quality of the on-board clocks. They work quite well, and the quality of the I2S signal is dependent largely on the technology used (CPLD vs.

Use a USB to I2S adapter, such as an Amanero or an XMOS-based device.

It works OK, but is useless to us audiophiles. Due to that, its real resolution is in the neighbourhood of 11 bits. It’s very easy to get it to work, but the sound quality is pretty bad, since it uses PWM to generate the sound. If you hear audio crackling or if games are slow like 55fps, you may need to use 44.1KHz instead.There are currently four ways to get audio out of the RPi: The default rate, 48KHz, should be OK in most case.

For example: audio_device = 'hdmi:CARD=PCH,DEV=0'īut please bear in mind that you need to stop retroarch before editing the configuration file. The config key for the audio device is audio_device. To list those cards, you have use the command line interface and type one of these commands: aplay -Lĭiscard all samples (playback) or generate zero samples (capture)ĭefault ALSA Output (currently PulseAudio Sound Server)Ģ.1 Surround output to Front and Subwoofer speakersĤ.0 Surround output to Front and Rear speakersĤ.1 Surround output to Front, Rear and Subwoofer speakersĥ.0 Surround output to Front, Center and Rear speakersĥ.1 Surround output to Front, Center, Rear and Subwoofer speakersħ.1 Surround output to Front, Center, Side, Rear and Woofer speakers Switching audio device manually Listing your audio cards You need to restart RetroArch for this change to take effect. In recent versions of Lakka, you can go to the Audio Settings and switch the Audio Device using the left and right keys. So if you get no sound, it means you need to switch to another card. Lakka can use only one of these cards at a time. For example, on Cubieboard2, the first card hw:0,0 will output through jack, while the second card hw:0,1 will output through HDMI. Some boards such has Cubieboard2, Banana Pi, Cuboxi, or Hummingboard have two or three audio cards. Configuring audio has become tricky on devices with more than one audio card.

Lakka raspberry pi 3 sound via hdmi