# 節點控制 RFID
``` arduino=
#include <SoftwareSerial.h>
#include <SPI.h>
#include <MFRC522.h>
#include "wheel.h"
#define L_ENA 9
#define L_ENB 3
#define L_IN1 7
#define L_IN2 6
#define L_IN3 5
#define L_IN4 4
SoftwareSerial BT(2, 8); // 接收腳, 傳送腳
#define RST_PIN 9
#define SS_PIN 10
MFRC522 *mfrc522;
double kP = 1.4;
double kI = 0.02;
double kD = 5;
int vB = 80;
int counter = 0;
String string = "";
char val;
char Forward = '1';
char Right = '3';
char Left = '4';
char GoBack = '2';
char Halt = '5';
void MotorWriting(wheel wheel_L, wheel wheel_R, int vL, int vR){
wheel_L.power(vL);
wheel_R.power(vR);
}
wheel wheel_L(L_ENA, L_IN1, L_IN2);
wheel wheel_R(L_ENB, L_IN3, L_IN4);
bool RFID(){
if(mfrc522->PICC_IsNewCardPresent() && mfrc522->PICC_ReadCardSerial()){
Serial.println(F("**Card Detected:**"));
mfrc522->PICC_DumpDetailsToSerial(&(mfrc522->uid));
mfrc522->PICC_HaltA();
mfrc522->PCD_StopCrypto1();
return true;
}
return false;
}
/*void translate(double target)
{
int output =target < 0 ? -1*target : target;
int output2 =target < 0 ? int(-100*target)%100 : int(100*target)%100;
Serial.println(target);
if(target < 0)
BT.write('-');
int temp[10] ={};
int i =0;
for(; output > 0; ++i)
{
temp[i] +=output%10;
output /=10;
}
for(;i >= 0; --i)
BT.write(temp[i]+48);
BT.write('.');
BT.write(output2/10+48);
BT.write(output2%10+48);
BT.write("\n");
}*/
double Tracking(){
int m= digitalRead(A2);
int l2= digitalRead(A1);
int l3= digitalRead(A0);
int r2= digitalRead(A3);
int r3= digitalRead(A4);
static double last =0;
static double sumError=0;
double dError=0;
double error=l3*-2 + l2*-1 + r2*1 + r3*2;
int sum=l3 + l2 + m + r2 + r3;
if(sum!=0){
error *= 100/(sum*2);
dError=(error-last);
sumError += error;
int vL=0,vR=0;
/*if(error<15 || error>-15){
vL = vB + 1*error ;//+ 3*dError;
vR = vB - 1*error ;//- 3*dError;
}
else{
vL = vB + kP*error + kD*dError + kI*sumError;
vR = vB - kP*error - kD*dError - kI*sumError;
}*/
vL = vB + kP*error + kD*dError + kI*sumError;
vR = vB - kP*error - kD*dError - kI*sumError;
if (BT.available()) {
val = BT.read();
string += val;
}
static int i=0;
if(sum == 5){
if(string[i] == Forward){
MotorWriting(wheel_L,wheel_R,80,80);
delay(800);
}
if(string[i] == Right){
MotorWriting(wheel_L,wheel_R,125,-75);
delay(800);
}
if(string[i] == Left){
MotorWriting(wheel_L,wheel_R,-75,125);
delay(800);
}
if(string[i] == GoBack){
while(!RFID()){
MotorWriting(wheel_L,wheel_R,50,50);
}
MotorWriting(wheel_L,wheel_R,125,-125);
delay(800);
}
i++;
}
if(error >= 150){
//sumError = 0;
counter = 0;
}
else{
counter += 1;
}
MotorWriting(wheel_L,wheel_R,vL,vR);
}
else
{
MotorWriting(wheel_L,wheel_R,-75,-75);
sumError = 0;
}
/*translate(error);
translate(dError);
translate(0.2*sumError);
BT.write("\n\n\n");*/
last =error;
return error;
}
void setup() {
Serial.begin(9600);
BT.begin(9600);
Serial.println("BT is ready!");
SPI.begin();
mfrc522 = new MFRC522(SS_PIN, RST_PIN);
mfrc522->PCD_Init();
Serial.println(F("Read UID on a MIFARE PICC:"));
}
double last;
void loop() {
double current =Tracking();
last =current;
}
```