| ??? 05/29/07 12:21 Read: times |
#139966 - No Extra Hardware Needed - I do not agree Responding to: ???'s previous message |
While what Michael propose (No Extra Hardware Needed) is "in theory" corrct, I have always had a problem with uC pins directly to the outside. Where a HC chips is easily protected (it can suck 20mA of current if overloaded without being harmed), the typical uC pin will die if the applied voltage exceed the Vin max. Another advantage would be that using schmitt triggers as input buffers would clean up the signals beautifully and 'pulse count' to me say industrial = noisy.
I would use schmitts and a serial resistot and a small parallel capacitor. The series resistor eould limit then overcurrent at the schmitts inputs and the network would filter noise, then the schmitt would square it up. Erik |
| Topic | Author | Date |
| 12 parallel pulses counting | 01/01/70 00:00 | |
| How fast are these pulses? | 01/01/70 00:00 | |
| pulses speed | 01/01/70 00:00 | |
| More info | 01/01/70 00:00 | |
| Pulse rate | 01/01/70 00:00 | |
| Isn't it slightly more complicated? | 01/01/70 00:00 | |
| Stretching pulses | 01/01/70 00:00 | |
| Another Quick Way | 01/01/70 00:00 | |
| Sampling timer with a buffer | 01/01/70 00:00 | |
| Showing Vertical Couners | 01/01/70 00:00 | |
| Yes other interrupt are also there | 01/01/70 00:00 | |
| Avoid using interrupts where possible | 01/01/70 00:00 | |
| Run signals frequency... | 01/01/70 00:00 | |
| PLC can be dirt cheap | 01/01/70 00:00 | |
| PLCs | 01/01/70 00:00 | |
an xcellent idea | 01/01/70 00:00 | |
| Sample with 2 74LS165 parallel loadShiftRegisiters | 01/01/70 00:00 | |
| would not the output pins drop... | 01/01/70 00:00 | |
| No Extra Hardware Needed | 01/01/70 00:00 | |
| No Extra Hardware Needed - I do not agree | 01/01/70 00:00 |