| ??? 11/03/09 07:31 Modified: 11/03/09 08:44 Read: times |
#170378 - Vastly over complicated! Responding to: ???'s previous message |
Mark Anthony Manlimos said:
Of all the things ive read about using the ldr as the sensor is that the output of the ldr is analog and not digital. thats why they use the adc... But you don't actually care about the analogue value, do you? All you need to know is whether your light beam is broken or not - which is, essentially, a digital quesion! If you've done any study about LDRs, you must have seen them used in things like simple dawn/dusk light controllers where a lamp switches ON at dusk (ie, when it gets dark) and OFF at dawn (ie, when it gets light again) - surely? You just need a simple threshold circuit to decide whether the LDR is "dark" or "bright"... There is a well-known type of cicuit that provides this threshold detection, with hysteresis - can you think of its name...? |
| Topic | Author | Date |
| Automated Car Parking System using LDR interfaced with 8051 | 01/01/70 00:00 | |
| about the attached picture | 01/01/70 00:00 | |
| all this is quite simple except ... | 01/01/70 00:00 | |
| A lot of things to think about | 01/01/70 00:00 | |
| Never mind "how" - why?? | 01/01/70 00:00 | |
| Weight of cars? | 01/01/70 00:00 | |
| ADC because... | 01/01/70 00:00 | |
| Possible but maybe not needed | 01/01/70 00:00 | |
| Vastly over complicated! | 01/01/70 00:00 | |
| Real problem | 01/01/70 00:00 | |
Basic research! | 01/01/70 00:00 |