Tag Archives: open source

Help wanted – Linux kernel development

tux_enhanced_penguin_linux_art-1979pxTo improve our HiFiBerry drivers (especially for the HiFiBerry Digi), we’re looking for somebody who can support us with some kernel development. The person should be familiar with the ALSA sound subsystem. We need to create a sound subdevice similar to the sound driver for the HDMI output. This will be included in the official Raspberry Pi Linux kernel.

Is somebody interested in supporting us here? Contact us!

HiFiBerry Digi support in Raspberry Pi Linux kernel

hbdigi-proto-raspberryOur HiFiBerry Digi will be available soon. Now, another major step in development has been finished: The HiFiBerry Digi support is included in the official Raspberry Pi Linux 3.10 kernel. If you’re interested in the source code, check out the pull request on Github.

I want to thank Florian Meier – the author of the Raspberry Pi I2S kernel module – for his great support. During the last weeks, I learned a lot about GIT and Linux kernel patches.

HiFiBerry DAC support in Raspbmc

logoSam Nazarko has released a new version of the Raspbmc distribution. There are a lot of interesting changes but one is especially exciting to us: It now has ALSA sound card support including a kernel with HiFiBerry DAC support.

We did not have the time to test it yet but we will do this soon! Did somebody test it already?

Are you interested in buying the HiFiBerry DAC – check out our HiFiBerry website. You can order the DAC kit there.

Update 29.12.: It seems that one necessary kernel module for HiFiBerry is still missing in the Rasmbmc december release.  We will check with the Raspbmc developer to see how this can be fixed.

Link

LabtoolTo debug digital circuits (mostly I2C, I2S and SPI communications between chips), I still use my old LogicPort 34-channel logic analyzer. When I bought it several years ago, it was a real bargain. There where no comparable logic analyzer available in this price range. However today, there are alternatives. One that I found today is LabTool from Embedded artists. It is not only a logic analyzer, but also features an oscilloscope, a logic level signal generator, and an analog signal generator.

The specs are not very impressive: 100MHz samples rate only with 2 channels used, only 20MSamples/s per channel with all 11 channels used. Also the integrated oscilloscope has a bandwidth of 6MHz and a max. sample rate of 60Ms/s – even cheap DSOs have much more impressive specs. However, I like this board. First it is inexpensive: €99 for a device with so many used is a very attractive price point. Also the software is open source. If I look at the software of my LogicPort, there are so many things I would like to change. However, the vendor does not seem to be interested in further development. With an open-source software there is at least a chance, that people from the community will expand the software.

This is not a top-notch device for professional use, but I is interesting for hackers and makers that do not want to spend too much money and want to use it to design digital circuits. I’m not sure about the analog part. 6MHz bandwidth  should be enough to debug audio circuits. I’m interested if somebody is using it for audio – leave a comment about your experiences if you do.

HiFiBerry DSP code repository

6a00d8341c767353ef016762f7c808970b-800wiI started with the programming for the HiFiBerry DSP light. Basically the software uses the program generated by Sigma Studio and writes it to the EEPROM module on the HiFiBerry DSP or directly to the DSP chip. In both cases the code is the same, only the I2C address is different. The software will be open-source, you can have a look at the current version on GitHub. It is not fully functional yet, it is not even an alpha version, but a work-in-progress.

The first software version will be a command-line-only version. There are also plans to have a web interface that you can use from your PC or even your mobile phone. A loudspeaker crossover that can be changed from your mobile phone? Yes, you can do it. Turning room equalization on or off from your mobile phone – you can do this too. Sounds cool? Are you interested to help with the development? Contact me!