Arduino control with serial input more then 1 character - arduino

Question

I have the script below and it works.
But I want to control it with a word like on or off instead of one character.
I tried and searched a lot but without success.
/*
Simple LED sketch
*/
int led = 13; // Pin 13
void setup()
{
pinMode(led, OUTPUT); // Set pin 13 as digital out
// Start up serial connection
Serial.begin(115200); // baud rate
}
void loop()
{
if (Serial.available()) {
int ser = Serial.read(); //read serial as ascii integer
if (ser == 'a') { //is this serial byte the ASCII equivalent of 0 through 9?
digitalWrite(led, HIGH); // on
Serial.println("aan");
}
else if (ser == 'u') {
digitalWrite(led, LOW); // off
Serial.println("uit");
}
}
}

Answer 1

Use Serial.readStringUntil(terminator) to read a string from the serial.
The sent string needs to be terminated with a newline character.
Chose Newline in the Arduino IDE's Serial Monitor.
String cmd = "";
void loop()
{
if (Serial.available()) {
cmd = Serial.readStringUntil('\n');
if (cmd == "on") {
digitalWrite(led, HIGH); // on
Serial.println("aan");
}
else if (cmd == "off") {
digitalWrite(led, LOW); // off
Serial.println("uit");
}
}
}

Answer 2

Your problem is that you are using a char you need to declare a string so you can compare that string to the input, the guy above gave a ok/very slacky/too complex for you answer (sorry no offense I am just trying to show contrast between a complex and a easy answer not trying to offend you) and partially is because he did not explain what he is doing and because he is doing unnecessary/useless work. There is a function in c++ called Serial.readString(), much easier then the stuff up there. Assuming your level of programming (no offense) from your question here is a quick review on data types:
String = ""
int = integer number {1,2,3,4,5,6,...}
char = '' <- Notice the difference from String = ""
float = floating point number {1.2,4.5,...}
(These are not all of them, there is more like byte and so on but just make sure you know how to use the above first)
/*
Simple LED sketch
*/
int led = 7; // Pin 13
String ser; //Declare the string that is going to store what your are going to
//write in the serial
void setup(){
// Start up serial connection
//It's good convention to start the serial before pinMode or any other thing
//in setup
Serial.begin(9600); //I don't know why you need such an high baud rate in
//your thing, 9600 for what you have to do is more than fine, this is just at
//what speed the serial is read (in a very general explanation)
pinMode(led, OUTPUT); // Set pin 13 as digital out
//make sure you put in here wheter you want to start the led "on" or "off"
//Eg you want it to start on, then digitalWrite(led, HIGH);
}
void loop(){
ser = Serial.readString();
if(Serial.available() == 0) { //You can also use a while loop if you want to
//This is telling the arduino: if there is something in the serial, then do...
if(ser == "on"){
Serial.println("on");
digitalWrite(led, HIGH);
}else if(ser == "off"){
Serial.println("off");
digitalWrite(led, LOW);
}
}
}
Hope it helped!
Also notice how the above code with
if(Serial.available())
This is a quite WEIRD and SHADY statement and might not work. That's because you are not really telling the int value into the function Serial.available
As the arduino guidelines specify:
int incomingByte = 0; // for incoming serial data
void setup() {
Serial.begin(9600); // opens serial port, sets data rate to 9600 bps
}
void loop() {
// send data only when you receive data:
if (Serial.available() > 0) {
// read the incoming byte:
incomingByte = Serial.read();
// say what you got:
Serial.print("I received: ");
Serial.println(incomingByte, DEC);
}
}
viewable here