3 ms·

I'm having trouble making my software ignore it. What command would write to the card when it has the write lock set?

• smolder 4y ago
  Perhaps it's not within the capabilities provided by the OS or the driver, because they're "well behaved", but the position of the switch is in essence a boolean sent to the host device and not a barrier to electrical signals that would write data.
• addaon 4y ago
  If you're on top of an OS, I can't say (depends on the OS)... but reading the switch is the responsibility of the reader, not the card. The card has no idea if it's write-protected (by the switch mechanism) or not. [1] Just using the same SPI operations you always use for write should work fine. There's not even a lock-status register or anything to check/clear first for the switch mechanism. https://superuser.com/questions/354473/is-the-lock-mechanism-on-an-sd-card-hardware-firmware-or-software-driver-os https://superuser.com/questions/354473/is-the-lock-mechanism...
• prmoustache 4y ago
  On linux you can use hdparm to switch the readonly boolean. On other OS I don't know but there is surely a way.
  • Aachen 4y ago
    Interesting, I'll try that next time, thanks!