Trying to read dip switches with microchip pic, can not compile firmware. Mplab X on Linux.

Hi, there's several things here.

Firstly, you mention trying to use scanf to read the switch, i.e. scanf (%d, switch1). You're assuming that your code will transparently do with a switch on a microcontroller what would occur with a keyboard on a PC, and that's not the case. C doesn't know what a keyboard is. There is an input/output library on PCs that knows what to do on a PC. Microcontrollers do not know what to do with a button.

Secondly, printf and scanf are part of a library, and at a minimum require

#include <stdio.h>

to use the library (and the minimum might not be enough to enable it). However as mentioned in the first point, having access to printf and scanf do not mean they will do anything, they may be stubbed out until the programmer (you) do something about that with custom code that either uses buttons or a serial port, and so on.

Thirdly, you should closely look over this code, which reads a dip switch:

// ********** global variables **********
// DIP switch input pins are GPIO 10, 11, 12
const uint8_t dipswitch[]={10, 11, 12};
// output pins:
const uint8_t led = 13;
// LED state
uint8_t ledState = 0;

// the special function named "setup" is automatically run once at startup
void setup() {
  int i;
  Serial.begin(9600); // initialize the serial port
  Serial.print("hello");
  // set up inputs
  for (i=0; i<3; i++) {
    pinMode(dipswitch[i], INPUT_PULLUP);
  }
  // set up outputs
    pinMode(led, OUTPUT);
}

// the special function named "loop"is run repeatedly, forever
void loop() {
  int i;
  // check if any dipswitch is enabled:
  for (i=0; i<3; i++) {
    if (digitalRead(dipswitch[i]) == LOW) {
      Serial.print("dipswitch #");
      Serial.print(i);
      Serial.print(" is pressed.\n");
    }
  }
  // toggle LED if the user presses the space bar
  if (Serial.available() > 0) { // one or more bytes are available to read
    if (Serial.read() == ' ') { // space bar was pressed
      ledState = ledState ^ 1; // toggle the variable
      digitalWrite(led, ledState);
    }
  }

  delay(100); // pause 100 msec before looping
}

That code is from a beginner-friendly environment (Arduino), and as you can see, it is very  easy-to-follow. If you're a beginner, I wouldn't recommend PIC as a starting point nowadays. You'll find thousands of examples and tutorials for more modern beginner-friendly microcontroller boards than PIC (it's not really the board, more the development environment support, libraries with functions specifically designed for beginners, and tutorials and examples). I understand you may already have a PIC board, but is it worth your time to struggle as a beginner when you could (for a few tens of $) work with a board and an environment designed for learning, where you can study and experiment at a very decent pace without needing a lot of help.

Hi, there's several things here.

Firstly, you mention trying to use scanf to read the switch, i.e. scanf (%d, switch1). You're assuming that your code will transparently do with a switch on a microcontroller what would occur with a keyboard on a PC, and that's not the case. C doesn't know what a keyboard is. There is an input/output library on PCs that knows what to do on a PC. Microcontrollers do not know what to do with a button.

Secondly, printf and scanf are part of a library, and at a minimum require

#include <stdio.h>

to use the library (and the minimum might not be enough to enable it). However as mentioned in the first point, having access to printf and scanf do not mean they will do anything, they may be stubbed out until the programmer (you) do something about that with custom code that either uses buttons or a serial port, and so on.

Thirdly, you should closely look over this code, which reads a dip switch:

// ********** global variables **********
// DIP switch input pins are GPIO 10, 11, 12
const uint8_t dipswitch[]={10, 11, 12};
// output pins:
const uint8_t led = 13;
// LED state
uint8_t ledState = 0;

// the special function named "setup" is automatically run once at startup
void setup() {
  int i;
  Serial.begin(9600); // initialize the serial port
  Serial.print("hello");
  // set up inputs
  for (i=0; i<3; i++) {
    pinMode(dipswitch[i], INPUT_PULLUP);
  }
  // set up outputs
    pinMode(led, OUTPUT);
}

// the special function named "loop"is run repeatedly, forever
void loop() {
  int i;
  // check if any dipswitch is enabled:
  for (i=0; i<3; i++) {
    if (digitalRead(dipswitch[i]) == LOW) {
      Serial.print("dipswitch #");
      Serial.print(i);
      Serial.print(" is pressed.\n");
    }
  }
  // toggle LED if the user presses the space bar
  if (Serial.available() > 0) { // one or more bytes are available to read
    if (Serial.read() == ' ') { // space bar was pressed
      ledState = ledState ^ 1; // toggle the variable
      digitalWrite(led, ledState);
    }
  }

  delay(100); // pause 100 msec before looping
}

That code is from a beginner-friendly environment (Arduino), and as you can see, it is very  easy-to-follow. If you're a beginner, I wouldn't recommend PIC as a starting point nowadays. You'll find thousands of examples and tutorials for more modern beginner-friendly microcontroller boards than PIC (it's not really the board, more the development environment support, libraries with functions specifically designed for beginners, and tutorials and examples). I understand you may already have a PIC board, but is it worth your time to struggle as a beginner when you could (for a few tens of $) work with a board and an environment designed for learning, where you can study and experiment at a very decent pace without needing a lot of help.