Open Hardware DSP Platform - Page 1
Forum section: electronics / projects

author: ohdsp
author_rank: Contributor
timestamp: March 03, 2017, 09:47:21 pm
content: Thought I would just share a project I have been working on called the Open Hardware DSP Platform.It is a range of modular boards for audio DSP applications, all licensed under TAPR open hardware license. All developed on KiCad (awesome package!).All released with no form of warranty or any guarantee they won't turn your toaster, pets, or family members into zombies, but I have tried my best to prevent this.Boards designs include:A DSP board based around the ADAU1452, designed to be used with Analog Devices SigmaStudio.A DAC board with the ADAU1966 from Analog Devices - an incredible value DAC chip with 16 output channels and insane specification for the price.Two ADC board designs, one for single ended stereo, one for balances stereo inputs.Also power supply, buffer boards for the DAC, and more as can be found on the website below.They are all 10cmx10cm PCBs (4 inch x 4 inch) at the moment, with interfacing through standard (26 AWG) ribbon cables.Work in progress website is here (with too many words and not enough pictures):www.ohdsp.org- Just a Weebly websiteReleased projects files and KiCad libraries are hosted on GitHub.github.com/ohdspSome are tested and working, others are still work in progress. I generally upload when I send PCB gerbers to get manufactured as it helps me keep track of board versions!Development repositories can be found on Bitbucket if you want to see what else is not released yet, although not much at the moment:bitbucket.org/pwzjNo idea if there will be much or any interest in a project like this and there are other similar options out there. I find what I am designing fulfills my needs better. This project started from an idea I had a few years ago, mainly as my AV amplifier had become "out of date". It wasn't that expensive but I was annoyed that 1 year later I could get a model with many more features (net radio, spotify, dlna player etc) for the same price, and I couldn't just upgrade my old one with a plug in module or something. While this project is far from doing this type of thing the basics seem to be getting there. I see no reason why the platform needs to be limited in functionality as time goes on; although I am sure I will hit many brick walls along the way.I do not sell boards or kits or anything like that at the moment; I would not even try this without a significant interest in the project. The cost would not be viable. I also have no interest in trying to milk any money out of this for the sake of it; although I did play with free easy to add banner adverts on the website which was a mistake.... Anyway they are gone now and I would just like to build something that does what I want and might be interesting to other people.Finally as a little introduction, I'm Paul and I am an Electronic and Electrical Engineer. It is my profession and theoretically I should know what I am doing, I do question if that is accurate sometimes though....Let me know what you thinkEdit:Attached a photo of my new (WIP) speaker crossover - with 2 balanced inputs, 8 single ended outputs, and room to expand if needed.

author: _Wim_
author_rank: Super Contributor
timestamp: March 03, 2017, 10:24:56 pm
content: Nice project! I use the EVAL-ADAU1452 eval board, and I really like it. Programming is super easy. Which that board also used the ADU1966, altough the AD1938 is also quite ok. Maybe I will look into your DAC board to extend my eval board, but for now to many other project going on.Keep us informed!

author: ehughes
author_rank: Frequent Contributor
timestamp: March 03, 2017, 11:20:53 pm
content: http://www.freedsp.cc/

author: ohdsp
author_rank: Contributor
timestamp: March 03, 2017, 11:26:57 pm
content: Correct there is FreeDSP, FreeDSP V2 which is meant to sit on a Raspberry Pi - in fact my project started as a Raspberry pi hat available as an unfinished design herehttps://github.com/pwzj/ohdsp- but the I2S support is rubbish and I have no interest in trying to rewrite any Linux Kernel code/modules to make it work, and there is also the extensive range of MiniDSP boards which are excellent (I own several pre-boxed products which are awesome), and have I missed any others?This thread is about my project though....

author: ohdsp
author_rank: Contributor
timestamp: March 04, 2017, 12:01:02 am
content: Quote from: _Wim_ on March 03, 2017, 10:24:56 pmThanks Wim, the AD1938 is a nice chip as well. From experience at a company I used to work for (think well respected high end audio), ALL of the Analog devices parts sound good, so that is all that matters... If you need more audio channels I could not find a better value chip than the ADAU1966, otherwise the AD1938 is not to be sniffed at as it is has 4 ADC channels and 8 DAC channels. I have though about a board based on this but have no use for it at the moment with my current designs.