All Questions
2 questions
3
votes
4
answers
2k
views
Reverse engineer this old burglar alarm panel
I took apart an old magnetic door alarm, where when the contact is broken it counts down from 10 seconds for the user to input the code (which ranges from 1 to 8, there is no 0 or 9 key). This alarm ...
- 253
0
votes
0
answers
41
views
LS7220 IC question for HIGH and LOW
I am learning about the basics of electronics.
I bought an LS7220 chip for a keypad lock, but using it turned out more difficult than I expected. I have attached it to a 9v battery at pins 9 and 14, ...
- 253