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I build a pressure sensor breadboard according to the schematic. It works, but has quite low sensitivity - it shows some pressure only after big pressure is applied.

Is there a way to increase sensitivity by replacing some components with different values, without redesigning the PCB?

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  • \$\begingroup\$ " it shows some pressure" What is the result, how are you measuring it? Please specify some quantitative data like volts or milli-volts. \$\endgroup\$
    – Oldfart
    Commented Jul 17, 2019 at 12:13
  • \$\begingroup\$ There is 0.08V on output when no pressure is applied, so my arduino analog pin reads 0. When I apply much pressure, it reads 1 and there are over 0.1 v. I would like to see readings starting from little pressure apply \$\endgroup\$
    – Laurynas Valuzis
    Commented Jul 17, 2019 at 13:10
  • \$\begingroup\$ You'll need to provide the datasheet for the sensor - to check its output impedance relative to the circuit, and its common mode output voltage. \$\endgroup\$
    – scorpdaddy
    Commented Jul 17, 2019 at 13:28
  • \$\begingroup\$ The sensor is MPS20N0040D. Input impedance of 4 - 6 KΩ, The output impedance of 4 - 6 KΩ, Full-scale output voltage 50 - 100 mV, Bridge Resistance to 4 - 6 KΩ, \$\endgroup\$
    – Laurynas Valuzis
    Commented Jul 17, 2019 at 13:40

1 Answer 1

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Without bothering about any of the other questions, if the zero-pressure output of your sensor is zero, just increase R8 by whatever factor you want. If the zero-pressure output is not zero, if you make R8 too big you will saturate.

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