| ??? 01/12/05 16:29 Read: times |
#84846 - external interrupt INT0 for echo signal Responding to: ???'s previous message |
i am basically timing the flight of a sonar transducer. I need to blank the recevier signal after pulsing the transmitter for 2.5ms to stop any ringing (false echos).
I am starting timer0 immediately after the pulse signal and when the echo is returned to input pin 3^2 (INT0) an external interrupt routine is performed to stop the timer, copy TH0 and TL0, and jump to a function to calculate the distance and output it to the serial. At the moment i am using timer1 to time the 2.5mS, during which time all external interrupts are disabled. Then after 2.5mS the external interrupts are enabled in timer1 isr. |
| Topic | Author | Date |
| blanking a false external interrupt | 01/01/70 00:00 | |
| Dangerous | 01/01/70 00:00 | |
| error prone | 01/01/70 00:00 | |
| external interrupt INT0 for echo signal | 01/01/70 00:00 | |
| Ok, what's the problem? | 01/01/70 00:00 | |
| Why ? | 01/01/70 00:00 | |
| project based design | 01/01/70 00:00 | |
well... | 01/01/70 00:00 |