Not reaching all branches of a case statement - arduino

Question

My project is a dead bolt that uses RF key fob. It checks for unlock or lock button press and also checks if the lock is locked or not. I use a case statement for the various choices. I think for some reason the lock state isn't changing because I am only getting cases 2 and 4.
I watered down the output actions to light blinks for each case (case 1 blinks once case 2 twice etc..)
After each case executes it changes the Boolean lock state (locked = true)
Code
/*
This code will open a deadbolt
with RF remote or buttons and
knows the position of the lock
based on last action
12 RF/Button lock
13 RF/Button unlock
10 button lock
11 button unlock
8 Buzzer
9 Servo
A0 Servo location
4 LED lock
5 LED unlock
*/
const int lockrf = 12; //input to lock rf
const int ulockrf = 13; //input to unlock rf
const int butlock = 10; // button lock
const int butulock = 11; // button unlock
const int ulockled = 4; //led in lock button
const int lockled = 2; //led in ulock button
#include <Servo.h>
boolean lockstate = true;
void setup()
{
Servo deadbolt;
deadbolt.attach(9);
pinMode(butlock,INPUT);
pinMode(butulock,INPUT);
pinMode(ulockrf,INPUT);
pinMode(lockrf,INPUT);
pinMode(ulockled,OUTPUT);
pinMode(lockled,OUTPUT);
}
void loop()
{
//variables for code
int lockdeg = 0;
int ulockdeg = 90;
int lock_case = 0;
digitalWrite(ulockled,LOW);
digitalWrite(lockled,LOW);
if (digitalRead(lockrf)==HIGH || digitalRead(butlock)==HIGH && lockstate == true ) // locked press lock
{
lock_case=1;
}
if (digitalRead(lockrf)==HIGH || digitalRead(butlock)==HIGH && lockstate == false) // ulocked press lock
{
lock_case=2;
}
if (digitalRead(ulockrf)==HIGH || digitalRead(butulock)==HIGH && lockstate == true) // locked press ulock
{
lock_case=3;
}
if (digitalRead(ulockrf)==HIGH || digitalRead(butulock)==HIGH && lockstate == false) // ulocked press ulock
{
lock_case=4;
}
switch(lock_case)
{
case 1:
{
digitalWrite(lockled,HIGH);
delay(500);
digitalWrite(lockled,LOW);
delay(10);
lockstate=true;
break;
}
case 2:
{
digitalWrite(lockled,HIGH);
delay(500);
digitalWrite(lockled,LOW);
delay(500);
digitalWrite(lockled,HIGH);
delay(500);
digitalWrite(lockled,LOW);
lockstate=true;
break;
}
case 3:
{
digitalWrite(lockled,HIGH);
delay(500);
digitalWrite(lockled,LOW);
delay(500);
digitalWrite(lockled,HIGH);
delay(500);
digitalWrite(lockled,LOW);
delay(500);
digitalWrite(lockled,HIGH);
delay(500);
digitalWrite(lockled,LOW);
lockstate=false;
break;
}
case 4:
{
digitalWrite(lockled,HIGH);
delay(500);
digitalWrite(lockled,LOW);
delay(500);
digitalWrite(lockled,HIGH);
delay(500);
digitalWrite(lockled,LOW);
delay(500);
digitalWrite(lockled,HIGH);
delay(500);
digitalWrite(lockled,LOW);
delay(500);
digitalWrite(lockled,HIGH);
delay(500);
digitalWrite(ulockled,LOW);
delay(10);
lockstate=false;
break;
}
}
}

Answer 1

Your problem is operator precedence. Arduino follows C-language precedence, in which && is evaluated before ||. For example, this means that your first if statement is evaluated as if you had parentheses like so:
digitalRead(lockrf)==HIGH ||
(digitalRead(butlock)==HIGH && lockstate == true)
What happens here is that if lockrf is high, both of the first two if statements are true, so you first set lock_case to 1, then to 2. You get a similar effect when ulockrf is high. This is why you get only cases 2 and 4.
To fix this, add parentheses to disambiguate:
if ((digitalRead(lockrf)==HIGH || digitalRead(butlock)==HIGH)
&& lockstate == true )
Good programming practice suggests using parentheses if there's any doubt.