THERMO LM35 DZ with PIC16F877

[Tuane06]

sorry i posted here.Help me,I have a proplem with LISY300AL,i dont know start how,it have 3mv sensitive and max range is 300 deg/s,i must choose a ADC 10bits?12bits? and how is it caculated?

 

[ericgibbs]

This is my circuit. The button is for switching between C and F

Ive tried doing what's in the datasheet (adding the diodes and res) to be able to measure negative degrees. I think I can work with the negative, just altering my codes. But now, the problem lies with the positive ones.
**broken link removed**

hi,
In my earlier post I did explain that the output from the LM35 [with diodes] is between the TOP of the diodes cathode] and the LM35 output pin.

You either have to use two adc pins, convert the voltages and then do some maths to work out the actual tempr.
Or
use OPA's to give a single ended output.

 

[worthyrabbito]

Got figure out the trick. I connected the LM35's Vout to AN0 then the Gnd just above the diode to AN1. Then subtracted the two to get the actual temperature. I've manage to measure up to -18C since at that temperature, Fahrenheit would be equal to 0.

Now, the problem lies with using the correct transistor. I'm now having common anode for the project, question is, how will I know what transistor is suitable? For now, Im using 2N3906. it won't work in proteus. I tried actual testing, it won't work also.

 

[sahu]

i have lm 35based temp display on lcd. if req. me.

 

[kensquall]

Picbasic

hello derrick..do you have a PICBASIC program in your digital thermometer?our teacher require us to use a picbasic not assembly...huhuhu