🛠 High-speed MicroSD card access via optimized SPI
M5Stack PaperDIY Complete Kit · avance · Maximisation du débit d'écriture sur la carte MicroSD en utilisant le bus SPI haute fréquence et le DMA.
Hardware: PaperDIY Complete Kit, UHS-I Class 10 MicroSD card. 2. Setup: Verify SPI pins dedicated to the SD slot in the PaperDIY schematic. Configure the SPI bus at 40 MHz or higher if wiring allows. 3. Code: Use SDMMC library or an optimized SPI implementation. Enable DMA mode for block transfers. Avoid small file writes; write minimum 4 KB blocks. 4. Management: Implement an in-memory filesystem (RAM) to accumulate data before writing to the card, reducing wear and interrupts. 5. Verification: Measure sustained write throughput. It must exceed 1 MB/s. Verify data integrity with a checksum. 6. Deep dive: Implement a journaled filesystem (e.g., LittleFS) to ensure data consistency in case of sudden power loss.