Scaling
The ADC Pi is an Analogue to Digital converter for the Raspberry Pi
11/09/2018
Posted by:
phoneman
Using this line of code to read a value......adc = ADCPi(0x68, 0x69, 12)
I don't see 12 bit referenced in the docs, but this is how the example is written so I am making that assumption.
The sensor I am using has output of 0.5 at 0 PSI and 4.5V at 2,500 PSI.
Looking for direction on how to figure the scaling factor to apply against the reading.
Thanks
I don't see 12 bit referenced in the docs, but this is how the example is written so I am making that assumption.
The sensor I am using has output of 0.5 at 0 PSI and 4.5V at 2,500 PSI.
Looking for direction on how to figure the scaling factor to apply against the reading.
Thanks
11/09/2018
Posted by:
andrew
Location:
United Kingdom
Without a datasheet for the sensor, it is difficult to be certain but assuming the output is linear and the pressure doesn't go below 0 PSI then it looks like there is a 0.5V offset for the output voltage so taking away that 0.5V you have 4V for 2500 PSI. Divide 2500 by 4 and it should be 625 PSI per volt.
So you should be able to use the formula:
Pressure = (Voltage - 0.5) * 625
So you should be able to use the formula:
Pressure = (Voltage - 0.5) * 625
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