Arduino Controlled RC Car

Using Arduino Project Guidance
1

I am planning for a project that uses Serial communications through an HC12 wireless serial module and an Arduino Uno on a RC car and controller. I have written some code and I would like some more eyes to look it over and point out any problems. I am gonna use the following code for the Arduino on the Car(receiver)

#include <SoftwareSerial.h>
#include <Servo.h>
#define relay 8
#define ESC 9
Servo steering;
SoftwareSerial HC12(2,3);
void setup() {
    HC12.begin(9600);
    Serial.begin(9600);
    steering.attach(10);
    steering.write(90);
    delay(100);
}

void loop() {
   if(HC12.available()>0){
     char val=HC12.read();
     switch (val){
       case 'a':
       {
         analogWrite(ESC,250);
         digitalWrite(relay, HIGH);
         break;
       }
       case 'b':
       {
         analogWrite(ESC, 204);
         digitalWrite(relay, HIGH);
         break;
       }
       case 'c':
       {
         analogWrite(ESC,153);
         digitalWrite(relay,HIGH);
         break;
       }
       case 'd':
       {
         analogWrite(ESC,102);
         digitalWrite(relay,HIGH);
         break;
       }
       case 'e':
       {
         analogWrite(ESC,51);
         digitalWrite(relay,HIGH);
         break;
       }
       case 'f':
       {
         analogWrite(ESC,0);
         digitalWrite(relay,LOW);
         break;
       }
       case 'g':
       {
         analogWrite(ESC,51);
         digitalWrite(relay,LOW);
         break;
       }
       case 'h':
       {
         analogWrite(ESC,102);
         digitalWrite(relay,LOW);
         break;
       }
       case 'i':
       {
         analogWrite(ESC,153);
         digitalWrite(relay,LOW);
         break;
       }
       case 'j':
       {
         analogWrite(ESC,204);
         digitalWrite(relay,LOW);
         break;
       }
       case 'k':
       {
         analogWrite(ESC,255);
         digitalWrite(relay,LOW);
         break;
       }
       case 'l':
       {
         steering.write(0);
         break;
       }
       case 'm':
       {
         steering.write(25);
         break;
       }
       case 'n':
       {
         steering.write(50);
         break;
       }
       case 'o':
       {
         steering.write(75);
         break;
       }
       case 'p':
       {
         steering.write(100);
         break;
       }
       case 'q':
       {
         steering.write(125);
         break;
       }
       case 'r':
       {
         steering.write(150);
         break;
       }
     }
   }
}

And the following code for the controller(sender)

#include <SoftwareSerial.h>
SoftwareSerial HC12(2,3);
#define xpin 4
#define ypin 5
void setup() {
    HC12.begin(9600);
    Serial.begin(9600);
}

void loop() {
    int val1=analogRead(xpin);
    int val2=analogRead(ypin);
    int xval=map(val1,0,1023,-3,3);
    int yval=map(val2,0,1023,-5,5);
    switch(xval){
      case -3:
      {
        HC12.write('l');
        break;
      }
      case -2:
      {
        HC12.write('m');
        break;
      }
      case -1:
      {
        HC12.write('n');
        break;
      }
      case 0:
      {
        HC12.write('o');
        break;
      }
      case 1:
      {
        HC12.write('p');
        break;
      }
      case 2:
      {
        HC12.write('q');
        break;
      }
      case 3:
      {
        HC12.write('r');
        break;
      }
    }
    
    
    switch(yval){
      case -5:
      {
        HC12.write('a');
        break;
      }
      case -4:
      {
        HC12.write('b');
        break;
      }
      case -3:
      {
        HC12.write('c');
        break;
      }
      case -2:
      {
        HC12.write('d');
        break;
      }
      case -1:
      {
        HC12.write('e');
        break;
      }
      case 0:
      {
        HC12.write('f');
        break;
      }
      case 1:
      {
        HC12.write('g');
        break;
      }
      case 2:
      {
      HC12.write('h');
      break;
      }
      case 3:
      {
        HC12.write('i');
        break;
      }
      case 4:
      {
        HC12.write('j');
        break;
      }
      case 5:
      {
        HC12.write('k');
        break;
      }
    }
    delay(100);
    Serial.println(millis());
}

The RC car already has a steering servo and a motor that I am planning on driving with a homemade h bridge motor driver(that is why there is a analog.Write to the the electronics speed controller or ESC, that will be my motor driver). Let me know what you think. Thanks!

2

Rather than us wander though your code, tell us what doesn't work.

Paul

3