ADC PIC MIKROBASIC VOLTAGE EXTRACTRATION FROM CLAMPMETER

[heina]

hi everyone. We're using a clampmeter in our project. We sort of extracted the part of the clampmeter where whenever its current measurement goes high, the voltage (in mV) in that particular area also goes high. We used PIC16F877a's adc in order to get it's value and be able to compute the energy and display it on LCD . However, when we were trying out the the circuit, the output ADC value read (in 10 bit binary) is not steady. I mean, it displays a value, like 2036 for example and then drops to 0 but the input voltage is steady in 2.36 mV for example.

uhm, any ideas why the adc returns to 0 when constant voltage is supplied as input?
uhm, any suggestions if we need some refining ic or something because we just connected the 2 pins from the clampmeter to the a0 port of the PIC directly.
pls help.

many thanks,
heina

here is my code:

'other declarations for the lcd and other stuff

Dim AD_Total as Word
Dim dummyCh as String[4]

TRISA = %111111   
ADCON1 = %10001111


While (b=TRUE)
    
     AD_Total = ADC_read(0)
    
   
      Delay_us(100)



     WordToStr(AD_Total, dummyCh)




     LCD_Out(4, 1, dummyCh)


     Delay_us(50)


  wend

 

[heina]

erm..pls help me ..:-( any ideas would be very helpful.. :-(