18.08.10
- Fixed inlining issue with 10.4 tools causing constraints fail
'WiPhonic' was a group project as part of the third year Computer Science & Electronics course at University of Bristol. See http://www.cs.bris.ac.uk/ for more information about the university and course.
The aim of the project was to design a product capable of streaming lossy audio from a PC over Wi-Fi to an XMOS-based device that can be connected to an existing powered speaker for maximum flexibility. The product specification was driven by cost, hence the decision to utilise a PWM audio DAC. MP3 decoding is done in real time on the chip.
A Java application running on the PC uses a unique method of parsing the MP3 file into packets. This reduces the buffer overhead on the XMOS and is more resilient to the audio effects of packet loss.
A final product could be implemented on an L2 with a small added BOM. An external DAC could be added for higher quality audio.
None. The code should compile but things will probably break.
- - The PWM routine contains an unknown bug causing noise on output if
the MP3 is heavily clipped. More investigation needed.
- - Decoding of mono MP3 files is disabled due to memory constraints.
Re-enabling it will require some more optimisation of the polyphase filter and/or optimisations else where.