What is wrong with the circuit? Can it be a board error?

[handsprince]

Board problem??

i had build one circuit with it receive data from LM35Dz then gain it with ca3160, the op-amp connect to PIC 16f877a. i'm sure that my program of PIC is correct. but the value is not show on the LCD. I ahd check the connection between op-amp and PIC. the output from Op-amp is 1.6V. can anyone tell me what is the possible problem?? thank you

 

[throwaway18]

Board problem??

Describe what you want to do in more detail. Showing us a circuit diagram may help.

Are you using one of the internal ADC's in the PIC?

>i'm sure that my program of PIC is correct.
Knowing what you don't know is a very important skill. Unless you have seen this software running correctly then you cannot be sure it is correct.

>the value is not show on the LCD
Describe exactly what happens. Does it not show a number at all, show a fixed incorrect number such as zero or show a randomly changing number?

 

[handsprince]

Re: Board problem??

i want receive signal from LM35dz and i gain the signal before connect to PIC internal ADC, do some calculation and display the temp on LCD.

 

[IanP]

Re: Board problem??

Instead of LM35+opamp connect a potentiometer to the same pin ..
With this potentiometer you will be able to simulate input voltage from 0 to 5V - this should help you to verify if your program is correct or not ..
Once you are satisfied that the value on the LCD display is relevant to the input voltage, re-connect LM35+opamp ..

Regards,
IanP