We continue to explore the rp2040 devices, very interesting microcontrollers. All prototype boards come with integrated SPI Flash. Raspberry Pi selected the LittleFS filesystem to manage this storage, a good compromise between functionality and performance.
Littlefs, the high-integrity embedded file system in Mbed OS is optimized to work with a limited amount of RAM and ROM. It avoids recursion, limits dynamic memory to configurable buffers and at no point stores an entire storage block in RAM. By focusing on a small set of multipurpose data structures, this high-integrity embedded file system uses 13K less ROM than FAT and 4K less RAM.
Here I’d like to explain the version 2 of the EMailSender library, a big evolution respect to version 1, with support for Arduino with w5100, w5200 and w5500 ethernet shield and enc28J60 clone devices, and support for esp32 and esp8266.
Now you can add attachments also, loaded from storage device like SD, SPIFFS or LittleFS per esp8266.
Here esp8266 and esp32 usage.