MikroElektronika PIC Microcontrollers PIC18 Instrukcja Użytkownika Pobierz pdf (Strona 39)

// Program loop. Read the temperature from analog temperature

// sensor

for(;;) // Endless loop

{

// Wait until a request is received

dt = 0;

while(!dt) dt = CANRead(&id, data, &len, &read_flag);

if(id == 500 && data[0] == 'T')

{

// Now read the temperature

temp = Adc_Read(0); // Read temp

mV = (unsigned long)temp

∗

5000 / 1024; // in mV

temperature = mV/10; // in degrees C

// send the temperature to Node:Display

data[0] = temperature;

id = 3; // Identifier

CANWrite(id, data, 1, send_flag); // send temperature

}

Figure 9.18: (Cont’d)

Node: DISPLAY Node: COLLECTOR

Initialize CAN module Initialize CAN module

Set mode to CONFIG Set mode to CONFIG

Set Mask bits to 1’s Set Mask bits to 1’s

Set Filter value to 3 Set Filter value to 500

Set mode to NORMAL Set mode to NORMAL

DO FOREVER DO FOREVER

Send character “T” with identifier 500 Read a character

Read temperature with identifier 3 IF character is “T”

Convert temperature to string Read temperature

Display temperature on LCD Convert to digital

Wait 1 second Convert to ºC

ENDDO Send with identifier 3

ENDIF

ENDDO

Figure 9.19: Operation of both nodes

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MikroElektronika PIC Microcontrollers PIC18 Instrukcja Użytkownika Strona 39