Hello all,
I've designed a crkt, to read sensor values, long story short, i have a rabbit MC, a bunch of sensors and ADC0808.
Used also opamp to amplify some senor outputs, the problem is this:
when i connect GROUND(0) to any input of the ADC0808 i get an output reading of 0.67 Volts! (Vcc=5, GND=0, Ref+= 5V, Ref- = GND).
the other weird thing is that alll the outputs for the temp and other sensors are exactly the same as input(no 0.67v shift), yet only for the Pressure sensor i get a 0.67V shift...if i measure the input using a voltmeter i get 3.9v, but the output reading of the adc is 4.5V!!), note also that all components are connected to the same Ground rail, so no difference in ground).
The pressure sensor i am using is "MPX4250A".
i'd appreciate any help...thanks!
I've designed a crkt, to read sensor values, long story short, i have a rabbit MC, a bunch of sensors and ADC0808.
Used also opamp to amplify some senor outputs, the problem is this:
when i connect GROUND(0) to any input of the ADC0808 i get an output reading of 0.67 Volts! (Vcc=5, GND=0, Ref+= 5V, Ref- = GND).
the other weird thing is that alll the outputs for the temp and other sensors are exactly the same as input(no 0.67v shift), yet only for the Pressure sensor i get a 0.67V shift...if i measure the input using a voltmeter i get 3.9v, but the output reading of the adc is 4.5V!!), note also that all components are connected to the same Ground rail, so no difference in ground).
The pressure sensor i am using is "MPX4250A".
i'd appreciate any help...thanks!
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