Charles Tritt / Mbed OS 21_Speaker_v5

First version. Demo of PWM setup and speaker operation. Fine grain control of the PWM parameters is an advantage Mbed has over the Arduino environment.

main.cpp@107:61b9c99a4e27, 2021-09-20 (annotated)

Committer:
CSTritt
Date:
Mon Sep 20 03:01:02 2021 +0000
Revision:
107:61b9c99a4e27
Parent:
105:ed03c03b353e
Child:
108:eee3167b25b4
First 2021 v5 version.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
CSTritt 107:61b9c99a4e27 1 /*
CSTritt 107:61b9c99a4e27 2 21_myBlink_v5 - Turns on an LED on and off for, repeatedly.
CSTritt 107:61b9c99a4e27 3 Last Revised: 9/19/21 (v. 1.0)
CSTritt 107:61b9c99a4e27 4 Based on mbed example. Modified by Dr. C. S. Tritt. This example code is in
CSTritt 107:61b9c99a4e27 5 the public domain.
CSTritt 107:61b9c99a4e27 6 */
CSTritt 107:61b9c99a4e27 7 // #include is a directive that "pastes" a file into your code.
CSTritt 107:61b9c99a4e27 8 // Use this specific #include at the beginning of each mbed program.
CSTritt 107:61b9c99a4e27 9 // mbed.h contains/points to the full definitions of our simple statements.
Jonathan Austin 0:2757d7abb7d9 10 #include "mbed.h"
CSTritt 107:61b9c99a4e27 11 // Define the object board_LED to be a digital output connected to LED1,
CSTritt 107:61b9c99a4e27 12 // which is the little green LED built into the Nucleo board.
CSTritt 107:61b9c99a4e27 13 DigitalOut board_LED(LED1);
CSTritt 107:61b9c99a4e27 14 const int WAIT_ON = 1400; // On time in seconds.
CSTritt 107:61b9c99a4e27 15 const int WAIT_OFF = 600; // Off time in seconds.
CSTritt 107:61b9c99a4e27 16 /*
CSTritt 107:61b9c99a4e27 17 The "main" function defines your main program -- it executes as soon as
CSTritt 107:61b9c99a4e27 18 you program the board. Functions can return (compute and give back) a
CSTritt 107:61b9c99a4e27 19 value. The main function could return an integer error code, so it begins
CSTritt 107:61b9c99a4e27 20 with int. Functions can also accept inputs. The main function cannot
CSTritt 107:61b9c99a4e27 21 however, so its round parentheses are empty.
CSTritt 107:61b9c99a4e27 22 */
CSTritt 107:61b9c99a4e27 23 int main() { // This curly brace marks the beginning of the main function.
CSTritt 107:61b9c99a4e27 24 // while() will repeat a set of actions as long as the statement inside
CSTritt 107:61b9c99a4e27 25 // its round parentheses is true. 1 is the definition of true, so
CSTritt 107:61b9c99a4e27 26 // while(1) and while(true) repeat forever.
CSTritt 107:61b9c99a4e27 27 while(true) { // This curly brace marks the start of the repeated actions.
CSTritt 107:61b9c99a4e27 28 board_LED = 1; // Turn on LED by storing a 1 in board_LED.
CSTritt 107:61b9c99a4e27 29 ThisThread::sleep_for(WAIT_ON); // Int value in mS.
CSTritt 107:61b9c99a4e27 30 board_LED = 0; // Turn off LED by storing a 0 in board_LED.
CSTritt 107:61b9c99a4e27 31 ThisThread::sleep_for(WAIT_OFF); // Int value in mS.
CSTritt 107:61b9c99a4e27 32 } // end of repeated actions
CSTritt 107:61b9c99a4e27 33 } // end of main function