How to make Botton increase number

//กำหนดตัวแปรตัวนับ digit

#define a 2

#define b 3

#define c 4

#define d 5

#define e 6

#define f 7

#define g 8

#define push_plus 9

#define push_minus 10

int digit_sum = 0;

int bottonstate1=0;

int bottonstate0=0;

int lastbottonstate1=0;

int lastbottonstate0=0;

void setup() //โปรดกดติดตาม กดแจ้งเตือน Facebook @เรียนคอมบาทเดียว , Youtube Chanel corecomcenter th

{

pinMode(a, OUTPUT);

pinMode(b, OUTPUT);

pinMode(c, OUTPUT);

pinMode(d, OUTPUT);

pinMode(e, OUTPUT);

pinMode(f, OUTPUT);

pinMode(g, OUTPUT);

pinMode(push_plus, INPUT_PULLUP);

pinMode(push_minus, INPUT_PULLUP);

Serial.begin(9600);

digit_count(digit_sum);

Serial.println(digit_sum);

}

//coding by corecomcenter th

void loop()

{

bottonstate1=digitalRead(push_plus);

bottonstate0=digitalRead(push_minus);

if(bottonstate1 != lastbottonstate1)

{

if(bottonstate1==HIGH)

{

if(digit_sum !=9)

{

digit_sum++;

digit_count(digit_sum);

Serial.println(digit_sum);

}else

{

digit_sum=digit_sum;

}

}else

{

digit_sum=digit_sum;

}

delay(200);

}

lastbottonstate1=bottonstate1;

if(bottonstate0 != lastbottonstate0)

{

if(bottonstate0 ==HIGH)

{

if(digit_sum !=0)

{

digit_sum--;

digit_count(digit_sum);

Serial.println(digit_sum);

}else

{

digit_sum=digit_sum;

}

}else//coding by corecomcenter th

{

digit_sum=digit_sum;

}

delay(200);

}

lastbottonstate0=bottonstate0;

}

void digit_count(int digit_led)

{

if(digit_led >=0 && digit_led <=9)

{

switch(digit_led)

{

case 9:

digitalWrite(a, HIGH);

digitalWrite(b, HIGH);

digitalWrite(c, HIGH);

digitalWrite(d, HIGH);

digitalWrite(e, LOW);

digitalWrite(f, HIGH);

digitalWrite(g, HIGH);

break;//coding by corecomcenter th

case 8:

digitalWrite(a, HIGH);

digitalWrite(b, HIGH);

digitalWrite(c, HIGH);

digitalWrite(d, HIGH);

digitalWrite(e, HIGH);

digitalWrite(f, HIGH);

digitalWrite(g, HIGH);

break;

case 7://coding by corecomcenter th

digitalWrite(a, HIGH);

digitalWrite(b, HIGH);

digitalWrite(c, HIGH);

digitalWrite(d, LOW);

digitalWrite(e, LOW);

digitalWrite(f, LOW);//coding by corecomcenter th

digitalWrite(g, LOW);

break;

case 6:

digitalWrite(a, HIGH);

digitalWrite(b, LOW);

digitalWrite(c, HIGH);

digitalWrite(d, HIGH);

digitalWrite(e, HIGH);

digitalWrite(f, HIGH);

digitalWrite(g, HIGH);

break;

case 5:

digitalWrite(a, HIGH);

digitalWrite(b, LOW);

digitalWrite(c, HIGH);

digitalWrite(d, HIGH);

digitalWrite(e, LOW);

digitalWrite(f, HIGH);

digitalWrite(g, HIGH);

break;

case 4:

digitalWrite(a, LOW);

digitalWrite(b, HIGH);

digitalWrite(c, HIGH);

digitalWrite(d, LOW);

digitalWrite(e, LOW);

digitalWrite(f, HIGH);

digitalWrite(g, HIGH);

break;

case 3:

digitalWrite(a, HIGH);

digitalWrite(b, HIGH);

digitalWrite(c, HIGH);

digitalWrite(d, HIGH);

digitalWrite(e, LOW);

digitalWrite(f, LOW);

digitalWrite(g, HIGH);

break;//coding by corecomcenter th

case 2:

digitalWrite(a, HIGH);

digitalWrite(b, HIGH);

digitalWrite(c, LOW);

digitalWrite(d, HIGH);

digitalWrite(e, HIGH);

digitalWrite(f, LOW);

digitalWrite(g, HIGH);

break;

case 1:

digitalWrite(a, LOW);

digitalWrite(b, HIGH);

digitalWrite(c, HIGH);

digitalWrite(d, LOW);

digitalWrite(e, LOW);

digitalWrite(f, LOW);

digitalWrite(g, LOW);

break;

case 0:

digitalWrite(a, HIGH);

digitalWrite(b, HIGH);

digitalWrite(c, HIGH);

digitalWrite(d, HIGH);

digitalWrite(e, HIGH);

digitalWrite(f, HIGH);

digitalWrite(g, LOW);

break;

}

}

else

{

digitalWrite(a, LOW);

digitalWrite(b, LOW);

digitalWrite(c, LOW);

digitalWrite(d, LOW);

digitalWrite(e, LOW);

digitalWrite(f, LOW);

digitalWrite(g, HIGH);

}

}//coding by corecomcenter th