Hello everyone !
I started to use Energia to create simple projects using MSP430G2553 LaunchPad and somehow I've succeded until now! Today I encountered a problem as I was trying to read values from a HIH-4000-001 humidity sensor.The sensor is powered with 5V and can return a value ranging from 0.826 V to 3.976V coresponding to 0 - 100 % RH. Because 3.976 V is much more than the MSP430 can manage I used a 1:2 resistive divider to scale down the signal.Moreover the sensor needs an load resistance of minimum 80kohms so the resistors I used for my divider were R1= 36kohms and R2=68kohms.NOW comes the error :
Regarding that , the RH level is normally around 50% that would corespond to a value of 1.3 V after the scale-down so in terms of ADC readings that would be around 445 and that is the value I get but, if I take multiple readings 1 sec apart of each other this is what happens :
445
442
443
0
0
0
443
440
.....................
Why 0 ? Can anyone tell me ? If I measure for some period of time the output of the sensor, the multimeter indicates a constant value of 1.3 V so I assume that the ADC is the problem! Please help me solve this issue as I need to create a functional project for my Bachelor Degree ! Thanks in advance !