sdioio on Feather RP2040 Adalogger#3
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Turn on the PIO SDIO driver for the Feather RP2040 Adalogger's built-in microSD slot, which is already wired for 4-bit SDIO on consecutive GPIOs (CLK=GPIO18, CMD=GPIO19, DAT0..3=GPIO20..23). Set CIRCUITPY_SDIOIO = 1 and add the standard SDIO_CLOCK / SDIO_COMMAND / SDIO_DATA0..3 pin aliases plus the SDIO_DATA four-pin tuple, matching the Metro RP2350 board's pattern so board.SDIO_DATA works out of the box. Tested on hardware: mounts at 25 MHz 4-bit and benchmarks ~9.6 MB/s write, ~8.1 MB/s read (bulk 4096x16) vs ~1.9 / 1.8 MB/s over the SPI auto-mount on the same board and card -- roughly a 5x throughput improvement. The vendored SdFat PIO driver builds cleanly for RP2040 (the RP2350-only gpio_base block compiles out); firmware fits at 92% of the FLASH region. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
mikeysklar
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FoamyGuy
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Jul 3, 2026
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Builds on adafruit#11090 Enables the PIO
sdioiodriver on the Feather RP2040 Adalogger, whose built-in microSD slot is already wired for 4-bit SDIO on consecutive GPIOs2 files, 23 lines:
CIRCUITPY_SDIOIO = 1+ theSDIO_*aliases andSDIO_DATAtuple, mirroring the Metro RP2350 board.Feather RP2040 tested mounts at 25 MHz 4-bit, best-of-3 with Jeff Epler's benchmark, same board and card (64GB ExFAT A2/U3):