• State TI Thinks Resolved
  • Locked Locked
  • Replies 6 replies
  • Answers 2 answers
  • Subscribers 79 subscribers
  • Views 2211 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.

MSP430FR5869: MSP430FR5x comparator checking for wake up CPU

Kz777
Expert 7895 points
Part Number: MSP430FR5869

Hi Champs,

Is this able to read input value on MSP430 comparaterE module as LPM3 ?

So, we would like to monitor senor output voltage value at MSP430 comparater as LPM3. If this threashhold value is target value, MSP430 become active.

Is it possible ?

I

Regards,

Kaz

  • 0
    Guru 303640 points
    In LPM3, all clocks except ACLK are disabled. However, the COMP_E module does not use a clock, so it can still work. (See table 6-2 of the datasheet.)
  • 0 in reply to Clemens Ladisch
    TI__Guru 74066 points
    Hi Kaz,

    Clemens is correct - COMP_E should be available in LPM3 because it is not clocked.

    Regards,
    Katie
  • 0 in reply to Katie Pier
    TI__Expert 7895 points

    Hi Katie, All,

    Thanks for your input.

    I understand this is able to comp_E on LPM3.

    However, we would like to monitor some input voltage monitor on comparator at LPM3.

    If the some sensor input value go over threshhold voltage, MSP430 status change to "Active mode" and turn on ADC , is this correct ?

    If this is possible, we don't need set Timer interrupt.  i.e)Timer interrupt wake up each of 1ms and turn on active mode.

    So, in this case, we can reduce more power consumption in this use case.

    Regards,

    Kz777

  • 0 in reply to Kz777
    Guru 303640 points
    There is no direct connection between the comparator and the ADC.

    You could enable the comparator interrupt and start the ADC from the interrupt handler.
    Alternatively, replace COMP_E with the ADC's window comparator.
  • 0 in reply to Clemens Ladisch
    TI__Expert 7895 points
    Thanks. I understand these are independent. I think comp_E module has interrupt Flag when input voltage over thresh hold , is this flag able to wake up msp430 active mode from LPM3 ?
    If this is possible, could you introduce some sample code ?
  • 0 in reply to Kz777
    TI__Guru 74066 points

    Hi Kz777,

    When an interrupt is enabled with the interrupt enable bit, and the global interrupt enable (GIE) bit is also enabled, it will wake the part from LPM to service the interrupt even when in LPM3. There is a driverlib-based example found here: dev.ti.com/.../ Or you can also check the functionality in the device user's guide www.ti.com/.../slau367 COMP_E chapter section 29.2.8 Comparator_E Interrupts.

    For more general information on how interrupts work on MSP430 - you may want to check out this training video: https://training.ti.com/msp430-workshop-series-5-12-interrupts 


    I hope that this helps to clear things up.
    Regards,
    Katie

**Attention** This is a public forum