#include <VirtualWire.h>
#define IN1 3
#define IN2 5
#define IN3 6
#define IN4 11
unsigned long lastmsg = 0;
int lspd = 0, rspd = 0;
void setup() {
    Serial.begin(9600);
    pinMode(IN1, OUTPUT);
    pinMode(IN2, OUTPUT);
    pinMode(IN3, OUTPUT);
    pinMode(IN4, OUTPUT);
}
void loop() {
    if (Serial.available() > 0) {
        int a = Serial.parseInt();
        int b = Serial.parseInt();
        if (Serial.read() == '\n') {
            lspd = a;
            rspd = b;
            lastmsg = millis();
        }
    } else {
        unsigned int fade = (millis() - lastmsg) / 1000;
        //lspd /= fade;
        //rspd /= fade;
    }
    if (lspd > 0) {
        analogWrite(IN3, map(lspd, 0, 127, 0, 255));
        digitalWrite(IN4, LOW);
    } else {
        digitalWrite(IN3, LOW);
        analogWrite(IN4, map(lspd, 0, -128, 0, 255));
    }
    if (rspd > 0) {
        analogWrite(IN1, map(rspd, 0, 127, 0, 255));
        digitalWrite(IN2, LOW);
    } else {
        digitalWrite(IN1, LOW);
        analogWrite(IN2, map(rspd, 0, -128, 0, 255));
    }
}