This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

MSP430G2253: Capacitance measurement

Part Number: MSP430G2253
Other Parts Discussed in Thread: MSP430FR2522, MSP430FR2633, FDC2214, MSP430G2553

Hello,

I want to measure a cap in the range of 10 to 600 pF. Is there any sample code where I can measure the capacitance value for MSP 430G2553 ?

Thanks,

Sagar 

  • Hello Sagar,

    I highly recommend moving to and using one of our MSP430 CapTIvate Capacitive Sensing MCUs. The MSP430FR2633 and the MSP430FR2522 are both great capacitive sensing MCUs that can fit your needs. Our CapTIvate devices are also supported by the CapTIvate Design Center (www.ti.com/.../mspcaptdsnctr ) which can help get your capacitive sensing design off the ground faster!
  • Hello I just want to read baseline capacitance of a sensor. So for this application will this MSP work? As they have mentioned all MSP can read base capacitor value? If this can work can i get a sample code? I do not want to switch to different msp for now.
  • Hello Sagar,

    Its dependent on what you want to do with that baseline capacitance. what is your end goal or application here? If you need the measure an absolute number for capacitance and then make a decision, neither are good for this. I would check out TI's FDC Sensing solutions such as the FDC2214. these parts claim to read absolute capacitance values.

    If the base capacitance doesn't really matter much and you want to measure if a change of capacitance has happened, the MSP430FR2633 and its family of devices are your answer.

    We did have an old solution of capacitive sensing for our MSP430G2553 devices, it is even more limited than the newer CapTIvate parts and no longer supported. It was unable to do absolute capacitance measurements as well.

    Alternatively, you could setup some measuring circuit with the ADC and possibly a comparator. We have no examples of this though.
  • Two basic approaches: charge or discharge time or charge transfer. No special ardware needed and particularly effective via small capacitance.

    As shown here:

    In this particular case it is using capacitance to measure small current but the inverse is true as well: using a small current to measure capacitance.