Arduino: Ethernet TCP Read Data
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Sumber: http://forum.arduino.cc/index.php?topic=123756.0
Code
/*
Ethernet TCP client/server communications test/proof of concept
Programmed by Michael E. Landon on 09/20/2012
(With parts borrowed/stolen from Nick Gammon)
This is a primitive example of using the Arduino Uno w/Ethernet Shield
with outputs controlled and monitored through a TCP connection.
Reading an output's state:
Format: rx (where x= output to read. 0-7 valid in this test)
Writing to an output:
Format: wx:y (where x = output to write to. 0-7 valid in this test)
(y = boolian state to write. (0 or 1))
Output 0 = pin 2, Output 1 = pin 3, etc.
Only 8 contiguous outputs were available for this test, hence only 8 addressed.
Posted in the Arduino Forums to assist those who like me needed to see
how it was done!
*/
#include <SPI.h>
#include <Ethernet.h>
// Set values below to match your network needs:
byte mac[] = {0x54, 0x52, 0x49, 0x41, 0x44, 0x00}; // MAC Address
byte ip[] = {192, 168, 0, 4}; // Network Address
byte gateway[] = {192, 168, 0, 223}; // Gateway Address
byte subnet[] = {255, 255, 255, 0}; // Subnet Mask
EthernetServer server(23); // Set Server Port
EthernetClient client; // Define client
const int MAX_LEN = 10; // Maximum length of a command
void setup()
{
// Open serial communications and wait for port to open:
Serial.begin(9600);
while (!Serial) {
; // wait for serial port to connect. Needed for native USB port only
}
Ethernet.begin(mac, ip, gateway, subnet); // Start the Ethernet connection
server.begin(); // Begin acting like a server
for(int x = 2; x < 9; x++) // Set up pins 2-9
{ // (we will call them 0-7 in our commands)
pinMode(x, OUTPUT); // Make them all outputs
} // This is the maximum we can do with an UNO
} // A MEGA could easily handle more
void loop()
{
char command[MAX_LEN]; // Set up the command buffer
static int c = 0; // Set up a counter (static so it does not get overwritten outside of this loop
char inByte; // Set up a character buffer to grab the input
client = server.available(); // Check for server availability
if(client)
{
inByte = client.read(); // Read the character in the buffer
switch (inByte) // check for certain types
{
case 13: // carriage return: process the command
command[c] = 0; // make the current position a terminating null byte
DoCommand(command); // Process the command
c = 0; // reset counter for next time
break; // exit when done
case 10: // linefeed: Ignore it
break; // and skip to the end
default: // any character other than a CR or LF
if (c < (MAX_LEN - 1)) // put in the command string (until it's full)
{
command[c] = inByte; // command concactination
c++; // Increment our counter
}
} // end of switch
} // end of if statement
} // end of main loop
void DoCommand(char * cmd) // Command received: process it!
{
switch (cmd[0]) // Check first character of the command:
{
case 'r': // r = read pin's state
ReadPins(cmd); // Proceed to read the pin
break;
case 'w': // w = write a state to a pin
WritePins(cmd); // Proceed to write to the pin
break;
default:
client.println("ERROR_01"); // ERROR_01 = bad command - only 'r' and 'w' are acceptable
}
}
void ReadPins(char * cmd) // Read a pin state
{
//Serial.println("Reading"); //debug
byte x;
x = cmd[1] - 46; // We get an ASCII character of 0-7, which has a value in the range of 48-55
// by subtracting 46, we get a value of 2-9, which represent the pins used as outputs 0-7 for this test.
if((x > 9) || (x < 2)) // If the result is outside this range, we throw an error.
{
client.println("ERROR_02"); // ERROR_02 = invalid pin number
return; // and exit before we do any further harm.
}
client.print("Output "); // send out the TCP connection a message the output in question
client.print(x - 2);
if(digitalRead(x))
{
client.println(" is on."); // is currently on..
}
else
{
client.println(" is off."); // or off (as the case may be)
}
} // done with reading
void WritePins(char * cmd) // Write a pin state
{
byte x;
x = cmd[1] - 46; // We get an ASCII character of 0-7, which is a value in the range of 48-55
// by subtracting 46, we get a value of 2-9, which represent our 0-7 outputs for this test.
if((x > 9) || (x < 2)) // If the result is outside this range, we throw an error.
{
client.println("ERROR_02"); // ERROR_02 = invalid pin number
return; // and exit before we do any further harm.
}
if(cmd[2] != ':') // If the third character is not a colon, we throw an error.
{
client.println("ERROR_03"); // ERROR_03 = unknown separator
return; // and exit before we do any further harm.
}
switch (cmd[3]) // check the 4th character
{
case '0': // 0 = turn the output off
digitalWrite(x, LOW); // Write to the pin to turn it off
client.print("Output "); // Send out the TCP connection a message the output in question
client.print(x - 2);
client.println(" is off."); // is now turned off.
break;
case '1': // 1 = turn the output on
digitalWrite(x, HIGH); // Write to the pin to turn it on
client.print("Output "); // Send out the TCP connection a message the output in question
client.print(x - 2);
client.println(" is on."); // is now turned on.
break;
default:
client.println("ERROR_04"); // ERROR_04 = Only Boolean states allowed in this test.
}
}