Just sharing this experience here since SEO didn’t immediately lead me to the solution I needed.
I noticed my magic ring was acting a little funky with one of the elevator readers in my building, so I decided to check it out and rewrite.
- I ran the reader command,
lf hid readerand verified it was spitting out the correct info. - Then I ran the exact same clone command (i literally used ctrl-r reverse-i-search) of
lf hid clone --fc xxxx --cn yyyyy -w C1k35s. - Finally ran
lf hid readeragain just for good measure to check that it wrote correctly… instead I got nothing back.
A bit of searching later, and looking at solutions in various forum posts, I finally landed on this one that worked for me. Specifically, this part:
lf t55 write -b 0 -d 000880E0 -t
lf t55 write -b 0 -d 000880E0 --r0 -t
lf t55 write -b 0 -d 000880E0 --r1 -t
lf t55 write -b 0 -d 000880E0 --r2 -t
lf t55 write -b 0 -d 000880E0 --r3 -t
I re-ran the clone command and… it worked!
My guess is what happened is, I had the ring at a slight angle and some of the bits died in transit. I heard T55 chips were temperamental, now I see why.
Protip (also from that forum post): run lf tune before writing to test the voltage drop and find the best angle instead of just guessing.