| ??? 02/23/07 15:55 Read: times |
#133555 - a peculiar problem |
hi people,
i am doin a project which involves a pressure sensor the pressure sensor output is differential so i put in a differential amplifier.now wen i exert pressure by blowin then the voltage at the output of the amplifier rises from 4.7 to 4.8 volts..i got this 0.1 volts change alone with a capacitor and amplified it to about 1 or 2 volts(depending on the pressure i create wen i blow into the sensor)i give this output to adc and observe only the change of the MSB of the adc.wen i exert pressure the msb of the adc changes from 0 to 1....HERE STARTS THE PECULIAR PROBLEM..i give the msb as the input to AT89C2051..i hav programmed the 2051 in such a way tht wen the input goes high an output pin makes an o/p led glow..NOW WEN I CONNECT THE MSB TO THE INPUT PORT THE VOLTAGE AT THE PIN TIES ITSELF TO ZERO NO MATTER HOW MUCH PRESSURE I EXERT IT REMAINS ZERO..I DONTKNOW WHTZ THE PROB..I NEED HELP FROM ALL QUARTERS AS SOON AS POSSIBLE.. padu.. |
| Topic | Author | Date |
| a peculiar problem | 01/01/70 00:00 | |
| ? | 01/01/70 00:00 | |
| To what port pin do you connect the MSB? | 01/01/70 00:00 | |
| and a schematic | 01/01/70 00:00 | |
| 1s written to P3.0? | 01/01/70 00:00 | |
| Modify your user profile | 01/01/70 00:00 | |
| yes | 01/01/70 00:00 | |
| What shows the voltmeter,... | 01/01/70 00:00 | |
| multimeter | 01/01/70 00:00 | |
| So you have 0V all the time at P3.0,... | 01/01/70 00:00 | |
| wen i connect p3.0.. | 01/01/70 00:00 | |
| Yes, but what if the ADC isn't connected? | 01/01/70 00:00 | |
| no no .. | 01/01/70 00:00 | |
| Ok, different try... | 01/01/70 00:00 | |
| precisely.. | 01/01/70 00:00 | |
| Does it also work, ... | 01/01/70 00:00 | |
| i didnt try it.. | 01/01/70 00:00 | |
| Just to see, whether there's an internal damage | 01/01/70 00:00 | |
i never thought of that .. | 01/01/70 00:00 | |
| modified | 01/01/70 00:00 | |
| Thanks, please publish your schematic again... | 01/01/70 00:00 | |
| sure | 01/01/70 00:00 | |
| Thanks! | 01/01/70 00:00 |