Recently, I was constantly struggling with the fact that microchip was removing more and more support libraries, so it was not wise to rely on them in all projects. Anytime I return again to my old functions – if it used the support libs, there is a pretty good chance it is screwed.
So this code works with XC8 version 2.36 and doesn’t require the involvement of extra support lib.
Functions are already described a couple of times:
So, I am not going to stop by and describe it all again, just give the code which I tested on the PIC18F1230.
The uart file:
#include <xc.h>
void InitUart() //Initialization of UART
{
//PIC18F1230
SPEN = 1; //Serial Port enabled
TRISA3 = 1;
TRISA2 = 1;
/*------BRG to 8 bit async -----------*/
SYNC = 0;
BRG16 = 0;
BRGH = 0;
/*------end of BRG -------------------*/
/*-------BAUD rate coefficients-------
BRG 0 0 0
4M
2.4K - 25
9.6K - 6
19.2 - 2
57.6 - 0
8M
2.4K - 51
9.6K - 12
10M
2.4K - 64
9.6K - 15
19.2K - 7
--------------------------------------*/
SPBRG = 12; //9615 baudrate with 8MHz
TX9 = 0; //no need to use 9th bit
TXEN = 1;
//Reciever part
RCIE = 1; //RX interrupts enable
RX9 = 0;
CREN = 1;
}//InitUart
char BusyUSART(void)
{
if(!TXSTAbits.TRMT) // Is the transmit shift register empty
return 1; // No, return FALSE
return 0; // Return TRUE
}
void writeByteUart(char tx_data) //Writing of a single byte
{
TXREG = tx_data; // Write the data byte to the USART
}//writeByteUart
void writeDataUart( char *data)
{
do
{ // Transmit a byte
while(BusyUSART());
writeByteUart(*data);
} while( *data++ );
}
void NumToUart(unsigned int Num) //Number to uart procedure, max 5 digits
{
unsigned int bignum = 10000;
unsigned char numtemp = 5;
if (!Num)
{
writeByteUart('0'); //If num is equal to 0, no need to do anything
while(BusyUSART()); //wait till the buffer will be free
}
else
{
while(numtemp>0) //determine how many digits in the number
{
if (Num/bignum)
break;
numtemp--;
bignum = bignum / 10;
}
for (unsigned char i = numtemp; i>0; i--)
{
writeByteUart( (Num - (Num/(bignum*10))*bignum*10 )/bignum + '0'); //pushing digits one by one from left to right
while(BusyUSART()); //wait till buffer will be free
bignum = bignum/10;
}
}
}
char ReadUart()
{
char data; // Holds received data
data = RCREG; // Read data
return (data); // Return the received data
}Then a simple main file to test the stuff:
void main(void) {
//INTOSC TO 8MHz
IRCF2 = 1;
IRCF1 = 1;
IRCF0 = 1;
SCS1 = 1;
//INTOSC setup
InitUart(); //Initialization of USART
writeDataUart((char *) "diymicro.org\r\n");
writeDataUart((char *) "Testing one byte tx, wait for it it is - ");
writeByteUart('X');
writeDataUart((char *) "\r\nNow the number 25660 is about to roll - ");
NumToUart(25660);
//global interrupts, priority is disabled
IPEN = 0;
GIE = 1;
PEIE = 1;
while(1)
{
if (rx_data_recieved) //some data recieved
{
writeByteUart(rx_data_recieved);
while(BusyUSART());
rx_data_recieved = 0;
}
}//while(1)
}//main
void __interrupt(high_priority) HighISR(void)
{
if (RCIF)
{
rx_data_recieved = ReadUart();
}
}//high priority interruptsStill haven’t find the perfect solution for a terminal under Linux, somehow minicom stopped working properly and putty is not that convenient, so far using cutecom to check UART:
All worked fine, with no issues. The source code is available here.
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