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	Wed Mar 15 01:54:31 2017 +0000
+++ b/main.cpp	Wed Mar 15 02:24:10 2017 +0000
@@ -1,8 +1,23 @@
 #include "mbed.h"
 /*
     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). 
+    
+    Toggles RGB LED junctions in response to serial input.
+    
+    Suggested wiring...
+    
+    Common Anode LED (active low)
+    
+                           /-- 1 kΩ -- D9 (red)
+    + 3.3 to 5.0 V ----LED<--- 680 Ω -- D10 (green)
+                           \-- 680 Ω -- D11 (blue)
+    
+    Common Cathode LED (active high)
+    
+                /-- 1 kΩ -- D9 (red)
+    GND ----LED<--- 680 Ω -- D10 (green)
+                \-- 680 Ω -- D11 (blue)
+   
 */
 DigitalOut RedLED(D9); // Physically same as Arduino Digital pin 9.
 DigitalOut GrnLED(D10); // Physically same as Arduino Digital pin 10.