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RobMaker

Sleep frequency - 999ms vs. 1000ms

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Hi,

running this blinking led code on Launchpad MSP430FR2433

// Ultra Low Power Blink Example

#define LED RED_LED
  
void setup() {                
  for (int i = 2; i < 20; i++) {
      if (!(i == 11 || i == 12)){
        pinMode(i, OUTPUT);
        digitalWrite(i, LOW);
      }
  }
}

void loop() {
  sleep(2000);
  digitalWrite(LED, HIGH);   // turn the LED on (HIGH is the voltage level)
  sleep(3);
  digitalWrite(LED, LOW);    // turn the LED off by making the voltage LOW
}

resulting in this current profile:

image.thumb.png.82cd80df1fac91119a48a968eda0d3bf.png

The power consumption looks nice (with LED current limited via 3.3 kOhm) but the blinking frequency is rather 10 seconds instead of 2 seconds.

The launchpad is configured to run with external crystal.

Changing sleep(2000) to sleep(999) I got the following profile:

image.thumb.png.3cd17ac931453f13523d7f508883de21.png

The frequency is now OK but I am not sure if the same LPM mode is achieved during sleep phase.

Please, could someone give an insight about the difference? Can I run 2s blink frequency with ~1µA consumption during sleep phase?

Thanks in advance,

Robert

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Which version of the msp430 package are you running?

I don't have access to a MSP430FR2433 LaunchPad right now so ma not able to reproduce. Could you try replacing the setup loop with jus a pinMode(LED, OUPUT) to test if it you do see a 2 second blink?

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