| ??? 01/12/05 16:02 Read: times Msg Score: 0 +1 Good Answer/Helpful -1 Overrated |
#84840 - Using 74922 Responding to: ???'s previous message |
Hi Hemant
I am using 74C922 and I am happy with it. I did change to it because of nois in industrial application made key scanning by microcontroller not reliabel and the extra chip servs me well. Mike it's very cheep here and mayby old but reliabel. Using data avalibel for interrupt is easy if you did use right debounce capacitor. It seams not to care about noise if you pull -OE to ground and distance of keyboard to microcontroller is less then 5 meter . You don't have to care about key scanning and debouncing. I need only five portpins and can care about other things. Only on falling edge of data avalibel you read the scancode of the keyboardcontroller and do what ever you like with it. Hemant do you realy need a programm sample for this? Peter |
| Topic | Author | Date |
| how to use 74923 5X4 key encoder | 01/01/70 00:00 | |
| Throw away the 74923 | 01/01/70 00:00 | |
| Using 74922 | 01/01/70 00:00 | |
| free easy to use code | 01/01/70 00:00 | |
| no interrupt needed | 01/01/70 00:00 | |
| full chip names | 01/01/70 00:00 | |
| '74923 chip' | 01/01/70 00:00 | |
Mmmm .... mocha chips | 01/01/70 00:00 |