PIC Vietnam - xin các bác giải thích giùm em đoạn code này ạ

#define nut_1 pin_b0
#define led_1 pin_c0
#define led_2 pin_c1
#define tang pin_c2
#define giam pin_c3
#define set pin_c4
#define output_led_1(x) output_bit(led_1, x) // Lenh dieu khien chan led_1
#define output_led_2(x) output_bit(led_2, x) // Lenh dieu khien chan led_2
// Chuong trinh chinh.
void main (void)
{
//khai bao bien
int8 value; //bien chua gia tri cua bo ADC 8 bit
int8 error;
int8 count;
int8 tam; //bien xac dinh nhiet do C va do F
int8 tam1;
float t_max_f; //bien chua gia tri set nhiet do max
int8 t_max_c; //bien chua gia tri set nhiet do max
float do_f;
int8 do_c;

AD_Init();
error=3; //nhiet do sai so
lcd_init(); // Khoi dong C.LCD 2x16.
tam=0;
count=0;
lcd_gotoxy(1,1);
lcd_putc("THAM KHAO");
while(1)
{
// output_led_1(1);
// output_led_2(0);
//kiem tra xem co chuyen tu do C sang do F
if(!input(nut_1))
{
delay_ms(100);
tam1=input(nut_1);
}
else
tam1=1;
if(tam1==0&&tam==0)
tam=1;
else if(tam1==0&&tam==1)
tam=0;

value=read_adc();
do_c = value*2+error;
do_f = do_c*1.8+32;
lcd_gotoxy(1,1);
if(tam==1)
printf(lcd_putc,"Nhiet do:%5.0fF",do_f);
else
printf(lcd_putc,"Nhiet do:%5dC",do_c);
delay_us(20);

if (!input(set)) //kiem tra nut nhan set nhiet do max
{
delay_ms(100);
do
{
if (!input(tang))
{
count++; //tang nhiet do max 1 do
delay_ms(100);
}
else
{
if (!input(giam))
count--; //giam nhiet do max 1 do
delay_ms(100);
}
lcd_gotoxy(1,1);
if (tam==1)
{
t_max_f=count;
printf(lcd_putc,"Nhiet do:%5.0fF",t_max_f);
delay_us(20);
}
else
{
t_max_c=count;
printf(lcd_putc,"Nhiet do:%5dC",t_max_c);
delay_us(20);
}

}
while (input(nut_1));
delay_us(20);
}
// kiem tra va set trang thai led 1 va led 2
if (do_c<=t_max_c)
{
output_led_1(0);
output_led_2(0);
}
else
{
output_led_2(0);
output_led_1(1);
}
}
}
//ham adc
void AD_Init(void) //initialize A/D converter
{
setup_adc_ports(sAN0); //set analog input ports: A0,A1,A3
setup_adc(ADC_CLOCK_INTERNAL); //using internal clock
set_adc_channel(0); //input Analog at pin A0
delay_us(20); //sample hold time
}