adafruit / Adafruit_CircuitPython_SD

SD card drivers for Adafruit CircuitPython
MIT License
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Multiple block read fails with error 127 or 63. #25

Closed Anton-2 closed 5 years ago

Anton-2 commented 5 years ago

readblocks with multiple block fails when using fast/new cards. The card returns a non 0 status after CMD12 (end of transfert). It may work with old/small/slow cards when ignoring some 127 returns.

I suspect it's because we are releasing CS between reads. Preliminary testing of a modified version that does not release CS shows fiable reads, and performance around 250KB/s on a pyportal (24Mhz SPI bus). I expect to provide a PR for this in a few days, after more testing/cleanup.

Anton-2 commented 5 years ago

Fixed in #26