Hi,
Last night I zapped my self-made alarm clock with a good dose of ESD, after removing my shirt and then touching the aluminum case with my finger. The 7-segment display froze and showed some random characters, and after restarting it I noticed one segment being dead on every number. I fixed it by replacing two 74HC595 shift registers in it. The other ICs, including the AVR seemed to survive from the zap.
Some pictures here: **broken link removed**
**broken link removed**
Currently that aluminum case is not connected to anything, obviously leaving the clock vulnerable to ESD damage. The power comes from an SMPS type 12V wall-wart (originally from a WD external hard drive). Should I just connect the case into the circuit ground for ESD protection, or are there something else which would make that a bad idea?
Last night I zapped my self-made alarm clock with a good dose of ESD, after removing my shirt and then touching the aluminum case with my finger. The 7-segment display froze and showed some random characters, and after restarting it I noticed one segment being dead on every number. I fixed it by replacing two 74HC595 shift registers in it. The other ICs, including the AVR seemed to survive from the zap.
Some pictures here: **broken link removed**
**broken link removed**
Currently that aluminum case is not connected to anything, obviously leaving the clock vulnerable to ESD damage. The power comes from an SMPS type 12V wall-wart (originally from a WD external hard drive). Should I just connect the case into the circuit ground for ESD protection, or are there something else which would make that a bad idea?