Mikroelektronika MIKROE-350 データシート

if (dat[4] <> 0) then

' if message received successfully

cnt = 0

dat[4] = 0                     ' clear message received flag

j = dat[3]
for i = 1 to dat[3]            ' show data on PORTB

PORTB = dat[i-1]

next i
dat[0] = dat[0]+1              ' increment received dat[0]
Delay_ms(1)                    ' send back to slave

RS485Master_Send(dat,1,160)

if (cnt > 100000) then

' if in 100000 poll-cycles the answer

Inc(PORTA)                '   was not detected, signal

cnt = 0                         '   failure of send-message

RS485Master_Send(dat,1,160)

if (PORTA > 10) then

' if sending failed 10 times

PORTA = 0

RS485Master_Send(dat,1,50)   '   send message on broadcast

address

RS485 Slave code:

program RS485_Slave_Example

dim dat  as byte[20]                 ' buffer for receving/sending
messages

i, j 

dim rs485_rxtx_pin as sbit at PORTD.B2         ' set transcieve pin

rs485_rxtx_pin_direction 

as sbit at DDRD.B2   ' set transcieve

pin direction

' Interrupt routine
sub procedure interrupt() org 0x16

RS485Slave_Receive(dat)

main:

PORTB = 0                         ' clear PORTB

PORTC = 0                         ' clear PORTC

DDRB = 0xFF                       ' set PORTB as output

DDRC = 0xFF                       ' set PORTB as output

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- SOFTWARE AND HARDWARE SOLUTIONS FOR EMBEDDED WORLD

CHAPTER 6