Micro Code

Michael's blog about teaching, hardware, software and the things in between

New Audio Boards

March 24, 2019 — Michael Engel

Long time no post... lots of things have happened (more on this later) since last July. One of the positive results is that we have designed and built new boards for our Signal Processing course.

Like the previously used Keil MCB4300 boards, we use the LPC4357 (dual core Cortex M4 and M0) SoC as basis, here supported by 32 MB of SDRAM as well as NAND and NOR flash. Since we cannot handle BGA parts in-house, we created an adapter to use Waveshare's Open4357 board with our base board designed for the Cortex M3/LPC1778.

Sound is handled by the relatively ancient NXP UDA1380TT codec, as on the Keil board. This chip is discontinued since around the year 2006, so I had to obtain a number via a specialized IC broker. The advantage of using that codec is that we stay compatible with the Keil board and we can reuse our existing driver code. Strangely, Waveshare still sells add-on boards using the same codec chip (only in an LQFP instead of an SSOP package), so they either have some secret source for the chip or invested in a lifetime supply...

One other addition is the nice graphical OLED display that you can see in the picture.

Signal processing board

Tags: audio, DSP, Cortex-M4, signal processing