What MCU should I select for my project?
We typically recommend connecting the A121 sensor to an ARM Cortex-M4 or M33-based microcontroller. On the XM125 module, we use an STM32L431CBY6 with 128 kB Flash and 64 kB RAM. While this is sufficient for most use cases, the space available for customer applications may be somewhat limited.
Memory consumption varies depending on the use case. Our software user guides for different detectors and reference applications include a section describing memory consumption. These user guides are available for download at https://developer.acconeer.com/home/a121-docs-software/.
In general, approximately 90 kB of Flash is required for the Acconeer libraries and STM32 drivers, along with a few kB of RAM for stack and static allocations. The heap size is highly dependent on the configuration. To estimate heap usage for different configurations, you can use the Resource Calculator available in the Exploration Tool application.