User manual

382
mikoBasic PRO for PIC32
MikroElektronika
Library Example
The example demonstrates RS-485 communication. Master sends message to Slave with address 160 and waits for
a response. After the response is received, the rst byte of received data is incremented and sent back to the Slave.
The received data is displayed on PORTB while error on receiving (0xAA) and number of consecutive unsuccessful
retries are displayed on PORTD. Hardware congurations in this example are made for the LV-32MX v6 board and
PIC32MX460F512L.
Copy Code To Clipboard
program RS485_Master_Example
dim dat as byte[10] ‘ buffer for receving/sending messages
i, j as byte
cnt as longint
dim rs485_rxtx_pin as sbit at RF2_bit ‘ set transcieve pin
rs485_rxtx_pin_direction as sbit at TRISF2_bit ‘ set transcieve pin direction
‘ Interrupt routine
sub procedure interrupt() iv IVT_UART_2 ilevel 7 ics ICS_SRS
RS485Master_Receive(dat)
U2RXIF_bit = 0 ‘ ensure interrupt not pending
end sub
main:
cnt = 0
CHECON = 0x32
AD1PCFG = 0xFFFF
PORTB = 0
PORTD = 0
TRISB = 0
TRISD = 0
UART2_Init(19200) ‘ initialize UART2 module
Delay_ms(100)
RS485Master_Init() ‘ initialize MCU as Master
dat[0] = 0xAA
dat[1] = 0xF0
dat[2] = 0x0F
dat[4] = 0 ‘ ensure that message received ag is 0
dat[5] = 0 ‘ ensure that error ag is 0
dat[6] = 0
U2IP0_bit = 1 ‘ set interrupt
U2IP1_bit = 1 ‘ priority
U2IP2_bit = 1 ‘ to 7
URXISEL1_U2STA_bit = 0 ‘ 0x = Interrupt ag bit is set when a character is received
U2RXIF_bit = 0 ‘ ensure interrupt not pending