Many lines of development boards, especially the NUCLEO line from STMicroelectronics, have seen supply shortages over the past few years. This is a significant problem for DSP PAW since it currently only supports one (popular) NUCLEO variant.

Fortunately, this variant is in stock with distributors at the moment; though some are limiting purchase quantities. To avoid this issue, DSP PAW has two options:

1. Expand support for more NUCLEO boards.
2. Integrate an STM32 microcontroller into the "add-on" board to create a single, complete device.

Integration has been on the table ever since this project's inception: no need to worry about multiple PCBs, the device could be contained in a nice case; seems like the "professional/commercial" path forward.

However, the project's audience probably does not care for a integrated product. Keeping to an add-on boards lets students have their NUCLEO boards for other projects or study. Being able to switch the add-on board between NUCLEO variants lets users choose a microcontroller depending on their needs (memory, performance, other functionality?).

Since education is our primary target, DSP PAW will most likely remain with an add-on board for hardware. Maybe an integrated option will be offered in the future if there a better need for it comes around.

NUCLEO board support

Currently, the firmware requires an STM32 microcontroller with a >=72MHz clock, 96kB of RAM, and USB/ADC/DAC support. Hardware floating-point support would be a big plus too, since many algorithms will want decimal precision. Adding support for a new board to the firmware would take some work, but not be super difficult; ChibiOS does a decent job with hardware abstraction.

The add-on board fits to 64 and 144 pin NUCLEO boards. Most F7 and H7 NUCLEO options should be compatible, the same goes for F4 and L4. USB support is the primary thing to watch out for.

Some specific options I'm seeing:

• NUCLEO-F303RE
• NUCLEO-F446ZE
• NUCLEO-L496ZG