SCProtocol (Simple Command Protocol)

This is a simple protocol helper to send commands to the arduino. It is much less complex and has much less code than other communication protocols for the arduino. It has this limitations:

• The command is allways the first byte (max. 255 commands possible)
• The length of the command must be known in advance
• The command data are always passed as a char array (since the length is known before it is not passed to the method again)

Installation

Extract a ZIP of the library in the arduinos library folder.

Example

#include <SCProtocol.h>

SCProtocol scProtocol = SCProtocol();

void checkCallback(char* data) {
  Serial.println("OK AwesomeApp Version: 0.0.1");
}

void addTwo(char* data) {
  short a = data[0] - '0';
  short b = data[1] - '0'; 
  Serial.print("OK ");
  Serial.println(a + b);
}

void setup() {
  Serial.begin(9600);
  scProtocol.attach('C', checkCallback, 0);
  scProtocol.attach('+', addTwo, 2);
}

void loop() {
  while(Serial.available()) scProtocol.process(Serial.read());
}

Adding a method

The following method should be called by the library.

void checkCallback(char* data) {
  Serial.println("OK AwesomeApp Version: 0.0.1");
}

To attach it, we specify a command name (first byte) the callback function we defined above and the number of bytes we expect. If there are no bytes (0). The passed data array will be NULL if the command has 0 bytes data length.

scProtocol.attach('C', checkCallback, 0);

Result in a SerialPort session:

If the code is uploaded to the arduino, one can use the serial console to test the interface.

(Take care, there are now new lines at the end of the command)

-> "C"
<- "OK AwesomeApp Version: 0.0.1\n"
-> "+12"
<- "OK 3\n"
-> "+99"
<- "OK 18\n"
-> "X"
<- "BAD command unknown\n"