Our first prototype was very price efficient but not development efficient. We used a common camera processor as the main processing unit. That processor was adequate for our hardware needs. However, its software support was hopelessly out of date. We had to back port several drivers for modern peripheral chips (like the wifi module and the sound chips) into a kernel that was not designed to handle them. Very quickly, we found ourselves reinventing interfaces in the older kernel which would have led to system instability.
In addition to the software problem, our original architecture did not allow for any room to grow. If, in the future, we wanted to add special video and/or music processing the camera processor CPU would not be able to handle it. It was already performing at its peak ability.
To fix this problem, we decided to re-architect the product around a more powerful processor with good software support. Especially important to us was to pick a processor that had broad application and deep community support. For these reasons, we decided to use the Allwinner A64.
The Allwinner A64 is a popular processor for tablets. The kernel is reasonably up to date and there is an active community providing support. Since our product could be viewed as a tablet with a couple of amplifiers add, we felt this was the perfect choice. It is powerful, reasonably priced, available in mass production and reasonably well known by current manufacturers. Below is a block diagram of the new architecture.
We spent June and July creating a new schematic and layout for this new architecture. That effort is complete and new boards will be available at the end of August. While we did this work, we also implemented a new case design following along the guidelines developed by the Industrial Designer. That effort will be documented in the next post.