How to use multiple IR signals for doing the same thing? - c++

Question

I want to use different signals from different IR remotes to control a wheeled robot.
The robot is the Smart robot car kit v1.0 from Elegoo.
I used the infrared_remote_control_car.ino file from the disc with it.
I just added the #define JVC and the operators at the end.
The code looks like this:
#include <IRremote.h>
int receiverpin = 12;
int in1=9;
int in2=8;
int in3=7;
int in4=6;
int ENA=10;
int ENB=5;
int ABS=130;
unsigned long RED;
#define A 16736925
#define B 16754775
#define X 16712445
#define C 16720605
#define D 16761405
#define JVCfront 49816
#define JVCback 49688
#define JVCright 49704
#define JVCleft 49832
#define JVCmenu 49900
#define JVC3ok 49724
#define JVCstop 49856
IRrecv irrecv(receiverpin);
decode_results results;
void _mForward()
{
digitalWrite(ENA,HIGH);
digitalWrite(ENB,HIGH);
digitalWrite(in1,LOW);
digitalWrite(in2,HIGH);
digitalWrite(in3,LOW);
digitalWrite(in4,HIGH);
Serial.println("go forward!");
}
void _mBack()
{
digitalWrite(ENA,HIGH);
digitalWrite(ENB,HIGH);
digitalWrite(in1,HIGH);
digitalWrite(in2,LOW);
digitalWrite(in3,HIGH);
digitalWrite(in4,LOW);
Serial.println("go back!");
}
void _mleft()
{
analogWrite(ENA,ABS);
analogWrite(ENB,ABS);
digitalWrite(in1,LOW);
digitalWrite(in2,HIGH);
digitalWrite(in3,HIGH);
digitalWrite(in4,LOW);
Serial.println("go left!");
}
void _mright()
{
analogWrite(ENA,ABS);
analogWrite(ENB,ABS);
digitalWrite(in1,HIGH);
digitalWrite(in2,LOW);
digitalWrite(in3,LOW);
digitalWrite(in4,HIGH);
Serial.println("go right!");
}
void _mStop()
{
digitalWrite(ENA,LOW);
digitalWrite(ENB,LOW);
Serial.println("STOP!");
}
void setup() {
pinMode(in1,OUTPUT);
pinMode(in2,OUTPUT);
pinMode(in3,OUTPUT);
pinMode(in4,OUTPUT);
pinMode(ENA,OUTPUT);
pinMode(ENB,OUTPUT);
pinMode(receiverpin,INPUT);
Serial.begin(9600);
_mStop();
irrecv.enableIRIn();
}
void loop() {
if (irrecv.decode(&results))
{
RED=results.value;
Serial.println(RED);
irrecv.resume();
delay(150);
if(RED==(A || JVCfront))
{
_mForward();
}
else if(RED==(B or JVCback))
{
_mBack();
}
else if(RED==(C or JVCleft))
{
_mleft();
}
else if(RED==(D or JVCright))
{
_mright();
}
else if(RED==(X or JVCstop or JVCmenu or JVC3ok))
{
_mStop();
}
}
}
I tried different ways I saw on the internet for the OR operator as you can see.
Actually, the robot is always going forward.

Answer 1

Does the Serial.println(RED) always print out the expected value?
Your if-elseblock itself does not seem to be problematic at first glance. It doesn't matter if you use || or or. They are equivalent.
The problem is the way you are checking the value:
Therefore that you have parenthesis around your OR statement, you create a bool-value. if(RED==(A || JVCfront) translates to:
is A set or is JVCfront set; meaning, are they != 0 (yes they both are, so this expression is true
is RED == true (no it is not, because true represents 1 in integer)
so the code in that block is not being executed
If you want to solve it with an if-else, you need to:
if(RED == A or RED == JVCfront)
{
_mForward();
}
Anyway, I would suggest a switch-case statement:
switch(RED):
{
case A:
{
//intentional fallthrough
}
case JVCfront:
{
_mForward();
break;
}
case B:
{
//intentional fallthrough
}
case JVCback:
{
_mBack();
break;
}
case C:
{
//intentional fallthrough
}
case JVCleft:
{
_mleft();
break;
}
case D:
{
//intentional fallthrough
}
case JVCright:
{
_mright();
break;
}
case X:
{
//intentional fallthrough
}
case JVCstop:
{
//intentional fallthrough
}
case JVCmenu:
{
//intentional fallthrough
}
case JVC3ok:
{
_mStop();
break;
}
default:
{
_mStop();
}
}
I personally find this kind of code much easier to read, and more understandable.
Please note: If you dont put a break into a case, it automatically executes the next case as well. This is why I wrote //intentional fallthrough in this part of the code. P.e. when case A is executed, nothing happens. It just falls through into case JVCFront and executes everything there.