| ??? 11/13/09 17:10 Read: times |
#170759 - more info Responding to: ???'s previous message |
Per Westermark said:
Siddharth Das said:
Any solutions? No, but a suggestion. Rewrite your post, and supply much more information. Much, much more. What interrupts? What hardware? What software? What measurements performed? Anything else relevant to the problem? INT0 on AT89S52, interrupt is source is LM324 wired as a comparator,that is used to sense IR radiation. The reference voltage is set such that the comparator outputs a high to low pulse to the interrupt.The interrupt is setup as falling edge triggered and the ISR toggles the LED state each time an interrupt is received. The problem is when there is no such change in IR levels,the LED blinks nevertheless,which can only mean the ISR is being executed by false trigerring. Anything else I should mention? |
| Topic | Author | Date |
| interrupt trouble | 01/01/70 00:00 | |
| Much more info needed | 01/01/70 00:00 | |
| more info | 01/01/70 00:00 | |
| Have you looked at all signals? | 01/01/70 00:00 | |
| yet more info | 01/01/70 00:00 | |
| Some hints | 01/01/70 00:00 | |
| No | 01/01/70 00:00 | |
| Doesn't the '324 have an OC output? | 01/01/70 00:00 | |
| Very good | 01/01/70 00:00 | |
| Debugging time! | 01/01/70 00:00 | |
| no oscilloscope :( | 01/01/70 00:00 | |
| then try 'selective grounding' | 01/01/70 00:00 | |
| This might be the reason | 01/01/70 00:00 | |
| Dangerous approach! | 01/01/70 00:00 | |
| Correct | 01/01/70 00:00 | |
| hysteresis? | 01/01/70 00:00 | |
| aka positive feedback | 01/01/70 00:00 | |
Dead gap | 01/01/70 00:00 |