EdgeTriggeredInt

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This is a C language project that demonstrates edge triggered interrupts. An interrupt is invoked on falling edge of S3 (PB21). When S3 is touched (falling edge) the red LED (PB26) is toggled. The green LED (PB27) is toggled in the main program. The DOUTTGL31_0 register is used so the code is thread-safe. Build, debug, run the project.
 
In the following figure, the falling edge of PB21 triggers the interrupt. Notice the toggling on PB27 stops while the interrupt is serviced. The toggle on PB26 occurs within the ISR. The entire ISR requires about 2us to run.

Derived from Texas Instrument code

  • gpio_input_capture_LP_MSPM0G3507_nortos_ticlang
  • gpio_toggle_output_LP_MSPM0G3507_nortos_ticlang

Hardware Required

  • MSPM0G3507 LaunchPad™ Development Kit (LP-MSPM0G3507)
Pin assignments
  • Output: PB22 is blue LED2, index 49 in IOMUX PINCM table
  • Output: PB26 is red LED2, index 56 in IOMUX PINCM table
  • Output: PB27 is green LED2, index 57 in IOMUX PINCM table
  • Input: PA18 is S2 positive logic switch, index 39 in IOMUX PINCM table
  • Input: PB21 is S3 negative logic switch, index 48 in IOMUX PINCM table
LaunchPad Jumpers
  • Remove J16 J17 J18: Disconnects light sensor from the microcontroller PA22 PA27 PA26
  • J5: Connects PB22 to blue LED2
  • J6: Connects PB26 to red LED2
  • J7: Connects PB27 to green LED2

Simplified BSD License (FreeBSD License) Copyright © 2025, Jonathan Valvano, All rights reserved.
 
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