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); } } }

--- a/main.cpp	Thu Jan 19 14:23:37 2017 -0600
+++ b/main.cpp	Wed Mar 15 01:54:31 2017 +0000
@@ -1,15 +1,35 @@
 #include "mbed.h"
-//K64F
-Serial pc(USBTX, USBRX); // tx, rx
-Serial device(MBED_CONF_APP_UART1_TX, MBED_CONF_APP_UART1_RX);  // tx, rx
+/*
+    Serial2RGB main by C. S. Tritt, Last revised 3/14/17 (v. 1.0)
+    Toggles RGB LED junctions in response to serial input. Uses "unbuffered" 
+    reads (Enter, CR/LF not required). 
+*/
+DigitalOut RedLED(D9); // Physically same as Arduino Digital pin 9.
+DigitalOut GrnLED(D10); // Physically same as Arduino Digital pin 10.
+DigitalOut BluLED(D11); // Physically same as Arduino Digital pin 11.
+
+Serial pc(USBTX, USBRX); // Default settings are 9600 Baud, 8-N-1.
 
 int main() {
+    
+    RedLED = 0;
+    GrnLED = 0;
+    BluLED = 0;
+    char letter;
+    
     while(1) {
-        if(pc.readable()) {
-            device.putc(pc.getc());
-        }
-        if(device.readable()) {
-            pc.putc(device.getc());
+        if (pc.readable()) {
+            letter = pc.getc();
+            pc.putc(letter);
+            if (letter == 'r') {
+                RedLED = !RedLED;
+            }
+            else if (letter == 'g') {
+                GrnLED = !GrnLED;
+            }       
+            else if (letter == 'b') {
+                BluLED = !BluLED;
+            }       
         }
     }
 }