1/16/2025 at 7:26:51 AM
Long ago I worked on the firmware for a game controller. We started getting reports back of ghost inputs like stuck buttons and false presses after we sent some early hardware to media reviewers. Given the power of game media at the time, this was an immediate code red. We took shifts playtesting various video games for nearly a week straight just to try and replicate the issues. No luck, only the reviewers could manifest it. We were about to put reviewers on a plane to demonstrate the issue in person when I decided to clean my desk. In doing so I tossed a bare PCB running debug to the other side of the desk and my console went wild.Turns out the PCBs were shock/pressure sensitive, and the debouncing was just a bit off. Reviewers were getting really into their games and mechanically stressing the controllers. Stressed hard enough, the PCB would bend slightly, causing line level fluctuations and eventually ghost inputs. Back in the office we were just doing a job and not getting too emotionally involved in our playtesting.
Some new molds and review units later we shipped the working system. Percussive debugging has solved a number of otherwise intractable bugs over my career.
by AlotOfReading
1/16/2025 at 1:38:22 PM
Had a bug about two years ago that I just could not reproduce. In fact, only the engineer who reported it could reproduce it. Finally, I did "go to gemba" and went into the test lab and watched him use the machine.He was doing a complex operation and was young and fast enough to overcome the keypress reporting interval. Literally it was just someone doing something we didn't expect and doing it fast enough that the sequence got messed up.
by HeyLaughingBoy
1/16/2025 at 9:06:48 AM
> Percussive debuggingS-tier term. Will need to add that to my repertoire.
by forrestthewoods
1/16/2025 at 9:39:57 AM
Nothing a bit of percussive maintenance cannot solve!by gsck
1/16/2025 at 10:20:38 PM
As the old cartoon said: the repairman charged $5000 to come fix a machine. When he showed up with a hammer, walked up to the machine and gave it a whallop with a hammer and it immediately started working.The bossman asked for an invoice which he wrote up on the spot.
It consisted of two lines:
1) tapping the machine $5
2) knowing where to tap: $4995
Grin
by whitten