27-06-2012, 11:00 AM
Interfacing lm35 with PIC Controller
Interfacing lm35.docx (Size: 37.23 KB / Downloads: 31)
Output of LM35 is in the range of 10mV. This is too small for the controller to detect. So the signal is amplified using a OPAMP. Controller can detect any signal in the range of 100mv app and above.
LM35:
The LM35 series are precision integrated-circuit temperature sensors, whose output voltage is linearly proportional to the Celsius (Centigrade) temperature. The LM35 thus has an advantage over linear temperature sensors calibrated in
° Kelvin, as the user is not required to subtract a large constant voltage from its output to obtain convenient Centigrade scaling. The LM35 does not require any external calibration or trimming to provide typical accuracies of ±1⁄4°C at room temperature and ±3⁄4°C over a full −55 to +150°C temperature range. Low cost is assured by trimming and calibration at the wafer level. The LM35’s low output impedance, linear output, and precise inherent calibration make interfacing to readout or control circuitry especially easy. It can be used with single power supplies, or with plus and minus supplies .
The MPX5100/MPXV5100 series piezoresistive transducer is a state-ofthe-
art monolithic silicon pressure sensor designed for a wide range of applications,
but particularly those employing a microcontroller or microprocessor
with A/D inputs.