• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 78 subscribers
  • Views 1648 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

CCS/MSP430FR5969: Measuring super capacitor capacity with MSP430FR5969 board

Mirae Kim
Intellectual 450 points
Part Number: MSP430FR5969

Tool/software: Code Composer Studio

Hello, 

I am using MSP430FR5969 device. 

I have a question with measuring super capacitor capacity in this board. 

I set my device like the picture below which is getting source from external power supply(J10), using super cap(J2), charging super cap(J11) .

If I am measuring the GND and VCC in J8, Is it right that I am measuring the voltage from the super capacitor? or Am I getting the voltage straight from external source? 

Best regards, 

Mirae

  • 0
    TI__Mastermind 49692 points

    Hello Mirae,

    Thank you for your post and also for sharing a picture of your LaunchPad. You can find detailed information in Section 2.4.5 in the MSP430FR5969 LaunchPad™ Development Kit (MSP‑EXP430FR5969) User's Guide about how to properly charge the super cap, use the super cap, and configure the jumpers on the LaunchPad during charging and standalone running.

    More specifically, Section 2.4.5.2 will be very helpful to you. It talks about how to charge up the super cap using the voltage supplied by the USB cable from a PC. It mentions that you need to wait for 2 to 3 minutes to allow the super cap to charge up completely. I'd wait 5 minutes to be sure it's charged. In Steps 4 and 7, "V+" is mentioned. If you want to use an external power supply to charge up the super cap, I'd strongly recommend removing all the jumpers from the isolation header (J13). The Power Select jumper is already set to "External", so you can supply 3.3V and GND to the "Ext Power" pins (J12).

    After the super cap is charged up, you can disconnect the external power supply. The MSP430FR5969 will now start using the super cap as the power supply.

    Please let me know if this reference doesn't answer all your questions.

    Regards,

    James

    MSP Customer Applications

  • 0 in reply to James Evans
    Intellectual 450 points
    I really appreciate for detailed information.

    I have one more question which I am still not sure about.

    If I measure voltage at J9 after removing all the external voltage, then the voltage I get is a capacity of super capacitor?


    Best regards,
    Mirae
  • 0 in reply to Mirae Kim
    TI__Mastermind 49692 points

    Hello Mirae,

    Basically, yes. The voltage of the super capacitor will reflect it's available capacity. Obviously, after this voltage falls below the minimum supply voltage level required by the MSP430FR5969, it won't run. Thus, your capacity range won't be from V_fully_charged to V_zero_volts, but it will be from V_fully_charged to V_minimum_supply_voltage_required_by_MSP430.

    In case you have questions about how the voltage discharges from a capacitor, take a look at the following resource. Obviously, more current supplied by the super capacitor will cause the voltage to discharge more quickly.

    Regards,

    James

    MSP Customer Applications

**Attention** This is a public forum