Hacker News: pauli5

New comment by pauli5 in "Show HN: I replaced a $120k bowling center system with $1,600 in ESP32s"

pauli5 — Mon, 20 Jul 2026 01:30:37 +0000

With a materials to retail cost multiplier of x10 (which is on the low side), your system wouldn't be cheaper than the commercial one unless you can build and install it yourself. I doubt most centres would have the skills available to do this.

Nonetheless, you've done a fantastic job here.

New comment by pauli5 in "The R47: A new physical RPN calculator"

pauli5 — Tue, 11 Nov 2025 21:43:47 +0000

Yes, it's the DM42n hardware underneath. The keyboard and overlay are different and the firmware is written from scratch using the WP 34S mathematics code. This has a lot more functionality than the DM42n does.

New comment by pauli5 in "Why Does Integer Addition Approximate Float Multiplication?"

pauli5 — Fri, 14 Feb 2025 00:30:10 +0000

Correct.

Floats support both -0 and 0 they compare equal but their bit representations don't. Zero can be tricky.

Not a numbers (NaNs) always compare as false. Their bit representations won't.