So my #digimon #vitalbracelet arrived today. Packaging was a bit crushed but everything else was okay ...

Had to shed a light on those dim cards right away....

I had a gut feeling these may just use flash chips and are compatible with micro SD card slots.

Looks like my gut was right. Uses 4MByte flash chips from General Plus( GPR25L321 )

Here's the pin out :)

When the card is linked to the vitalbracelet. it writes a 8 byte signature at flash offset 0x10000.

To erase this signature (sector) the protection bits of the status register must be cleared first.

Looks like I found some sprites in the dump :D (inverted RGB-565 in big endian 16-bit words)

Let's spoil the whole spritesheet. Let's hope twitter can handle it

Making a cheap DIMcard reader is easy. CH341A mini programmer, short micro SD-card module and some female to female jumper wires. No tools required.

Would be nice to have some easy to use software as well. Started working on something ...

Sofar it's already useful to see if a DIMcard is linked yet or not (FYI the ID is not the actual ID).

And we got backup working. now we're getting somewhere