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Cycle between power states continuously?

Other Parts Discussed in Thread: MSP430FR5720

Disclosure: not very experienced, so keep that in mind when reading/replying

I am currently using an MSP430FR5720 in my system.  What I would like to do is cycle between an ON state and LPM.  Say, 100ms ON, 400ms LPM; something similar to that.  While the MCU is awake, that is when I will be listening for a signal on a channel.  If what is received is what I want, the system will stay awake for a certain amount of time, continuing its normal routines.

Does the MSP430 have this type of "power cycling" functionality?  Is this achieved through interrupts?  Any information is appreciated.


  • That's certainly possible. One way would be to use the timer peripheral to schedule the transition between operating modes.

    Can you provide more information on the signal you want to wait for and the routines you want to run when in active mode? Also, is the timing you mentioned critical to the application or just being done to reduce power consumption? Depending on the answers to those questions there may be more efficient ways to handle this than with a timer.

  • The signal I would be looking for is simply an analog RSSI value from an RF receiver (which receives data from a transmitter).  I will compare this received value with a hardcoded adc value.  If I determine that there was a transmission from the Tx to the Rx (not just ambient noise), then the system will wake.  While the system is awake, it will interpret any subsequent commands.  A timer will start after a command.  If it runs out, the system will go back to cycling power states.  The timing I will use will need to be initially optimized to receive the signal, then I will focus on the power reduction.  I will need to find a desirable medium between the two.