Charles Tritt / Mbed OS 21_SerialPass_v5

New example. Initial version.

main.cpp@117:e072f162cbce, 2021-10-17 (annotated)

Committer:
CSTritt
Date:
Sun Oct 17 13:54:15 2021 +0000
Revision:
117:e072f162cbce
Parent:
116:8990686eedf5 
Cleaned up comments.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
CSTritt 107:61b9c99a4e27 1 /*
CSTritt 116:8990686eedf5 2 Project: 21_SerialPass_v5
CSTritt 109:b061f9830736 3 File: main.cpp
CSTritt 111:956b1c606b66 4
CSTritt 117:e072f162cbce 5 This project demonstrates how to pass a Serial object to functions by reference.
CSTritt 117:e072f162cbce 6 It also introduces multi-file projects and C strings. It uses VT-100 escape
CSTritt 117:e072f162cbce 7 sequences to prevent scrolling and change text color.
CSTritt 117:e072f162cbce 8
CSTritt 117:e072f162cbce 9 The function approach to sending terminal control commands is awkward. It was
CSTritt 117:e072f162cbce 10 used to demonstrate the use of multiple functions each in their own file and
CSTritt 117:e072f162cbce 11 custom header files. The string constant approach used after the button is
CSTritt 117:e072f162cbce 12 better. It involves defining char array constants containing the escape codes.
CSTritt 117:e072f162cbce 13 The \x1B inserts the 1B_16 (escape) characters into the char vectors (really
CSTritt 117:e072f162cbce 14 "C strings" because they are "null terminated" (since they were created using
CSTritt 117:e072f162cbce 15 double quotes). Use the strings in printf statements to send the control text
CSTritt 117:e072f162cbce 16 to the terminal. There are probably even betters ways to do this, but this is
CSTritt 117:e072f162cbce 17 good enough for now.
CSTritt 117:e072f162cbce 18
CSTritt 116:8990686eedf5 19 See...
CSTritt 114:1cfad1babb55 20
CSTritt 116:8990686eedf5 21 * C Strings: https://www.tutorialspoint.com/cprogramming/c_strings.htm.
CSTritt 116:8990686eedf5 22 * String literal escape sequences (this is a different meaning than the VT-100
CSTritt 116:8990686eedf5 23 terminal escape sequences): https://en.cppreference.com/w/cpp/language/escape.
CSTritt 116:8990686eedf5 24 * VT-100 Escape sequences: http://www.csie.ntu.edu.tw/~r92094/c++/VT100.html
CSTritt 116:8990686eedf5 25 * ANSI Escape Sequences:
CSTritt 116:8990686eedf5 26 https://gist.github.com/fnky/458719343aabd01cfb17a3a4f7296797.
CSTritt 116:8990686eedf5 27 * ANSI Color Codes, etc.
CSTritt 116:8990686eedf5 28 https://www.lihaoyi.com/post/BuildyourownCommandLinewithANSIescapecodes.html.
CSTritt 114:1cfad1babb55 29
CSTritt 116:8990686eedf5 30 Calls
CSTritt 116:8990686eedf5 31
CSTritt 117:e072f162cbce 32 clrTerm - Clears terminal and places cursor at home position.
CSTritt 117:e072f162cbce 33 whiteText - Makes text white. Ackward to use. Done for demo.
CSTritt 117:e072f162cbce 34 blueText - Makes text blue. Awkward to use. Done for demo.
CSTritt 116:8990686eedf5 35
CSTritt 117:e072f162cbce 36 Written by: Dr. C. S. Tritt; Last revised 10/17/21 (v. 1.0)
CSTritt 107:61b9c99a4e27 37 */
Jonathan Austin 0:2757d7abb7d9 38 #include "mbed.h"
CSTritt 115:6ba84689e2c9 39 #include "myFuncs.h"
CSTritt 117:e072f162cbce 40
CSTritt 115:6ba84689e2c9 41 // Construct a USER_BUTTON digital input.
CSTritt 115:6ba84689e2c9 42 DigitalIn myButton(USER_BUTTON);
CSTritt 117:e072f162cbce 43 // Construct a Serial object for output only.
CSTritt 115:6ba84689e2c9 44 Serial pc(USBTX, NC, 9600);
CSTritt 108:eee3167b25b4 45
CSTritt 114:1cfad1babb55 46 int main()
CSTritt 114:1cfad1babb55 47 {
CSTritt 116:8990686eedf5 48 clrTerm(pc); // Clear the terminal at startup.
CSTritt 117:e072f162cbce 49 whiteText(pc); // Change text to white (likely the default).
CSTritt 116:8990686eedf5 50 pc.printf("Welcome to SerialPass.\n");
CSTritt 117:e072f162cbce 51 // This is awkward but demonstrates the use of multiple function files.
CSTritt 116:8990686eedf5 52 pc.printf("Press the ");
CSTritt 116:8990686eedf5 53 blueText(pc); // Change text to blue. There are better approaches to this.
CSTritt 116:8990686eedf5 54 pc.printf("blue User Button");
CSTritt 116:8990686eedf5 55 whiteText(pc); // Change text to white.
CSTritt 116:8990686eedf5 56 pc.printf(" to clear this and continue...\n");
CSTritt 117:e072f162cbce 57
CSTritt 116:8990686eedf5 58 // Wait here for button to be pressed (making it low, false).
CSTritt 116:8990686eedf5 59 while (myButton) {
CSTritt 117:e072f162cbce 60 ThisThread::sleep_for(10); // Yield some time to other threads.
CSTritt 116:8990686eedf5 61 }
CSTritt 117:e072f162cbce 62 // Display the most button text.
CSTritt 116:8990686eedf5 63 clrTerm(pc); // Clear the terminal.
CSTritt 116:8990686eedf5 64 const char red[] = "\x1B[31m";
CSTritt 116:8990686eedf5 65 const char white[] = "\x1B[37m";
CSTritt 116:8990686eedf5 66 const char blue[] = "\x1B[34m";
CSTritt 116:8990686eedf5 67 pc.printf("The screen should clear and this text appear in...\n");
CSTritt 117:e072f162cbce 68 // Note finish with white to leave terminal in the expected state.
CSTritt 116:8990686eedf5 69 pc.printf("%sred, %swhite, and %sblue%s.\n", red, white, blue, white);
CSTritt 114:1cfad1babb55 70 while(true) { // Main forever loop.
CSTritt 115:6ba84689e2c9 71 ThisThread::sleep_for(300000); // Sleep for 5 minutes, repeatedly.
CSTritt 108:eee3167b25b4 72 }
CSTritt 113:cc5beacdad5a 73 }