Mikroelektronika MIKROE-350 Datenbogen

This example demonstrates simple data exchange via software UART. If MCU is
connected to the PC, you can test the example from the mikroBasic PRO for AVR
USART Terminal Tool.

program Soft_UART

' Soft UART connections
dim Soft_UART_Rx_Pin as sbit at PIND.B0

Soft_UART_Tx_Pin 

as sbit at PORTD.B1

Soft_UART_Rx_Pin_Direction 

as sbit at DDRD.B0

Soft_UART_Tx_Pin_Direction 

as sbit at DDRD.B1

' End Soft UART connections

dim error_, counter, byte_read as byte   ' Auxiliary variables

main:

DDRB = 0xFF       ' Set PORTB as output (error signalization)
PORTB = 0                              ' No error

error_ = Soft_UART_Init(9600, 0) ' Initialize Soft UART at 9600 bps

if (error_ > 0) then

PORTB = error_                       ' Signalize Init error

while TRUE

nop                              ' Stop program

end if
Delay_ms(100)

for counter = "z" to "A" step -1  ' Send bytes from 'z' downto 'A'

Soft_UART_Write(counter)
Delay_ms(100)

next counter

while TRUE                             ' Endless loop

byte_read = Soft_UART_Read(error_) ' Read byte, then test error flag

if (error_ <> 0) then

' If error was detected

PORTB = error_                     '   signal it on PORTB

Soft_UART_Write(byte_read)         ' If error was not detect-

ed, return byte read

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- SOFTWARE AND HARDWARE SOLUTIONS FOR EMBEDDED WORLD

CHAPTER 6