Charles Tritt / Mbed OS Serial2RGB_N

This program demonstrates serial communications and digital output. I have a similar program for the Arduino Uno. The purpose of this program is to compare mbed and Arduino code.

Fork of Serial_ex_2 by mbed_example

This is the corresponding Arduino/Wiring .ino program:

/* Serial2RGB_A

Toggles RGB LED junctions based on characters received via serial connection. Echos characters sent.

Hardware Required:

Arduino (or similar board as written)

Created by Dr. C. S. Tritt

Revision History

16-07-07 v. 1.0 Initial development (on TI MSP432). 17-03-13 v. 1.1 Ported to Arduino boards. 17-03-14 v. 1.2 Added echo of read characters.

  • /

Use defines for pin IDs and other constants

  1. define RED_PIN 9 RED_LED
  2. define GRN_PIN 10 GREEN_LED
  3. define BLU_PIN 11 BLUE_LED
  4. define BAUD 9600 Other settings default to 8-N-1.

char inChar; boolean redState = LOW; boolean grnState = LOW; boolean bluState = LOW;

void setup() { Initialize the pins as an output. Assumes adjacent pins. for (int led = RED_PIN; led <= BLU_PIN; led++) { pinMode(led, OUTPUT); } Initialize serial communication. Serial.begin(BAUD); Set baud rate. }

void loop() { Read serial if available. if (Serial.available() > 0) { get incoming byte: inChar = (char) Serial.read(); Read and convert a value. Serial.print(inChar); Echo what was read. Use it to toggle outputs (LED states) if (inChar == 'r') { redState = !redState; digitalWrite(RED_PIN, redState); } else if (inChar == 'g') { grnState = !grnState; digitalWrite(GRN_PIN, grnState); } else if (inChar == 'b') { bluState = !bluState; digitalWrite(BLU_PIN, bluState); } } }

main.cpp@3:cbacf69dbed5, 2017-03-18 (annotated)

Committer:
CSTritt
Date:
Sat Mar 18 10:02:26 2017 +0000
Revision:
3:cbacf69dbed5
Parent:
2:f91fc3b8d8f7 
Cleaned up comments. Switched from 1 to true constant in while loop.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mab5449 0:8d318218bac1 1 #include "mbed.h"
CSTritt 1:fdb8ecdf954f 2 /*
CSTritt 3:cbacf69dbed5 3 Serial2RGB main by C. S. Tritt, Last revised 3/18/17 (v. 1.1)
CSTritt 2:f91fc3b8d8f7 4
CSTritt 3:cbacf69dbed5 5 Toggles RGB LED junctions in response to serial input. Echos input.
CSTritt 2:f91fc3b8d8f7 6
CSTritt 2:f91fc3b8d8f7 7 Suggested wiring...
CSTritt 2:f91fc3b8d8f7 8
CSTritt 2:f91fc3b8d8f7 9 Common Anode LED (active low)
CSTritt 2:f91fc3b8d8f7 10
CSTritt 2:f91fc3b8d8f7 11 /-- 1 kΩ -- D9 (red)
CSTritt 2:f91fc3b8d8f7 12 + 3.3 to 5.0 V ----LED<--- 680 Ω -- D10 (green)
CSTritt 2:f91fc3b8d8f7 13 \-- 680 Ω -- D11 (blue)
CSTritt 2:f91fc3b8d8f7 14
CSTritt 2:f91fc3b8d8f7 15 Common Cathode LED (active high)
CSTritt 2:f91fc3b8d8f7 16
CSTritt 2:f91fc3b8d8f7 17 /-- 1 kΩ -- D9 (red)
CSTritt 2:f91fc3b8d8f7 18 GND ----LED<--- 680 Ω -- D10 (green)
CSTritt 2:f91fc3b8d8f7 19 \-- 680 Ω -- D11 (blue)
CSTritt 2:f91fc3b8d8f7 20
CSTritt 1:fdb8ecdf954f 21 */
CSTritt 3:cbacf69dbed5 22 DigitalOut RedLED(D9); // Physically same as Arduino Digital pin 9 on Nucleos.
CSTritt 1:fdb8ecdf954f 23 DigitalOut GrnLED(D10); // Physically same as Arduino Digital pin 10.
CSTritt 1:fdb8ecdf954f 24 DigitalOut BluLED(D11); // Physically same as Arduino Digital pin 11.
CSTritt 1:fdb8ecdf954f 25
CSTritt 1:fdb8ecdf954f 26 Serial pc(USBTX, USBRX); // Default settings are 9600 Baud, 8-N-1.
mab5449 0:8d318218bac1 27
mab5449 0:8d318218bac1 28 int main() {
CSTritt 1:fdb8ecdf954f 29
CSTritt 1:fdb8ecdf954f 30 RedLED = 0;
CSTritt 1:fdb8ecdf954f 31 GrnLED = 0;
CSTritt 1:fdb8ecdf954f 32 BluLED = 0;
CSTritt 1:fdb8ecdf954f 33 char letter;
CSTritt 1:fdb8ecdf954f 34
CSTritt 3:cbacf69dbed5 35 while(true) {
CSTritt 1:fdb8ecdf954f 36 if (pc.readable()) {
CSTritt 1:fdb8ecdf954f 37 letter = pc.getc();
CSTritt 1:fdb8ecdf954f 38 pc.putc(letter);
CSTritt 1:fdb8ecdf954f 39 if (letter == 'r') {
CSTritt 1:fdb8ecdf954f 40 RedLED = !RedLED;
CSTritt 1:fdb8ecdf954f 41 }
CSTritt 1:fdb8ecdf954f 42 else if (letter == 'g') {
CSTritt 1:fdb8ecdf954f 43 GrnLED = !GrnLED;
CSTritt 1:fdb8ecdf954f 44 }
CSTritt 1:fdb8ecdf954f 45 else if (letter == 'b') {
CSTritt 1:fdb8ecdf954f 46 BluLED = !BluLED;
CSTritt 1:fdb8ecdf954f 47 }
mab5449 0:8d318218bac1 48 }
mab5449 0:8d318218bac1 49 }
CSTritt 3:cbacf69dbed5 50 }