Pull-up resistors on digital input

On the module RobDuino we can find two “on-board push button switches”. Wiring of this switches is presented in [@fig:RobDuino_OnBoardPwshButtonSwitch_s1], where can we noticed that both switches are connected to ground voltage potential.

Wiring of on-board switches.{#fig:RobDuino_OnBoardPwshButtonSwitch_s1}

To properly use this on-board push-button switches we must enable the pull-up resistors of A4 and A5 input of microcontroller.

Tasks:

  1. Configure pins A4 and A5 as inputs with pull-up resistor.
  2. At the end of the setup() function add the while-loop which will delay the execution of the program until we press the A4 key - acting as a “START BUTTON”.
  3. Use the A5 key to stop the robot and terminate the execution of the program.
#include <RobotMovingFunctions.h>
const int KEY_A4 = A4;
const int KEY_A5 = A5;

void setup()
{
  setIOpins();
  pinMode(KEY_A4, INPUT_PULLUP);
  // KEY_A5 setup here...
}

void loop()
{
  moveForward();
  //to-do: the key reading
  bool stopTheRobotKey = 0;
  if (stopTheRobotKey == 1)
  {
    stopTheRobot();
    exit(0);        //terminate the program
  }
}

: Pull Up Resistors on Digital Input. {#lst:290_Pull_Up_Resistors_on_Digital_Input}

Questions:

  1. What is the programming instruction of reading the value form digital input?
  2. Which values can be assigned to bool type variable?
  3. Explain the programming instruction exit(0).

Summary:

<++>

<++>

Issues:

<++>

<++>