News for hackers. Stuff that matters.

A comment on Ultrathin business card runs a fluid simulation. Parent comment

Re:Ultrathin business card runs a fluid simulation by hypercube33 on Friday August 08, 2025 @08:16AM (#44836120)
I half expected this to have a button/mode to show custom QR codes...
[ Parent | on HN ]
Re:Ultrathin business card runs a fluid simulation by mcdonje on Friday August 08, 2025 @10:33AM (#44837470)
That's a good idea!
[ Parent | on HN ]
Re:Ultrathin business card runs a fluid simulation by nine_k on Friday August 08, 2025 @02:15PM (#44839960)
Could as well display the name and/or email, if rotated just so.
[ Parent | on HN ]
[dead]
Re:Ultrathin business card runs a fluid simulation by hturan on Saturday August 09, 2025 @05:18AM (#44845132)
I might be wrong, but you might need need (at least) a 23x23 LED matrix to have a white border around the outside to give it the contrast needed (the "quiet zone", since QR data is black).
[ Parent | on HN ]
Re:Ultrathin business card runs a fluid simulation by phirks on Saturday August 09, 2025 @07:20PM (#44851287)
This is why my first prototype had a white border around it. The LEDs were red back then, so I don't know exactly what I was thinking, but I was aware of the problem.

https://github.com/Nicholas-L-Johnson/flip-card/blob/main/me...

[ Parent | on HN ]