Arduino Coding Serial Error

[surbyte]

@SkyCrafter, please post your full code.
It's impossible to help you if you don't help us!!

[TolpuddleSartre]

If you take the code posted above, and compile it for a Mega, you should see this:

Code: [Select]

Arduino: 1.6.12 (Linux), Board: "Arduino/Genuino Mega or Mega 2560, ATmega2560 (Mega 2560)"

/tmp/ccNfzOpl.ltrans0.ltrans.o: In function `main':
ccNfzOpl.ltrans0.o:(.text.startup+0x202): undefined reference to `loop'
collect2: error: ld returned 1 exit status
exit status 1
Error compiling for board Arduino/Genuino Mega or Mega 2560.

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.


If you put in a dummy loop

Code: [Select]

void setup() {
 Serial.begin(115200);
 passcodeCheck();
 
}
const int passcode = 1324;
int access = 0;
int incomingByte = Serial.read();

void passcodeCheck() {
  Serial.print("Enter Passcode: ");
  Serial.print(incomingByte);
 }


void loop (){} // <<< I ADDED THIS and compiled it, again, for a Mega, you should see this message

Code: [Select]

Sketch uses 2,090 bytes (0%) of program storage space. Maximum is 253,952 bytes.
Global variables use 204 bytes (2%) of dynamic memory, leaving 7,988 bytes for local variables. Maximum is 8,192 bytes.
.

The only way I can see that you could get a error for Serial not being defined, would be if you compiled the code for a processor that doesn't have a UART.

[SkyCrafter]

OOF.

[sterretje]

OOF.

Out of focus ?

[TolpuddleSartre]

OOF.

Did you have something to add, or are you just channeling a Gaston Lagaffe comic?

[surbyte]

This code compiles but you can´t control access with that, because you are reading only one char in passcodeCheck().

I just reorder your lines.

Code: [Select]

const int passcode = 1324;
int access = 0;
   

void setup() {
 Serial.begin(115200);
 passcodeCheck();
}

void loop() {
}

void passcodeCheck() {

  int incomingByte = Serial.read();
  Serial.print("Enter Passcode: ");
  Serial.print(incomingByte);
}

AVR Memory Usage
----------------
Device: atmega328p

Program:    1766 bytes (5.4% Full)
(.text + .data + .bootloader)

Data:        202 bytes (9.9% Full)
(.data + .bss + .noinit)


 [SUCCESS] Took 49.31 seconds

[03/29/18 11:29:19]

[SkyCrafter]

I need to collect at least 4 characters, as it will be a 4 digit passcode to unlock the system

[TolpuddleSartre]

Robin2 has a serial basics topic that covers all sorts of common serial issues.

[Robin2]

Robin2 has a serial basics topic that covers all sorts of common serial issues.

But that was way-back-when in Reply #8 and I assume the OP studied it carefully and decided s/he did not like it.

...R