| 0,0 → 1,106 |
|---|
| #include <xc.h> |
| #include "defines.h" |
| #include "UART.h" |
| |
| static UART_DATA *data_ptr; |
| |
| void UART_Init(UART_DATA *data) { |
| data_ptr = data; |
| |
| APFCON0bits.RXDTSEL = 1; // Change RX from RB5 to RC5 |
| APFCON0bits.TXCKSEL = 1; // Change TX from RB7 to RC4 |
| UART_RX_TRIS = 1; |
| UART_TX_TRIS = 0; |
| |
| SPBRG = 16; // Set baud rate to 115200 @ 32MHz |
| BAUDCONbits.BRG16 = 0; // 8-bit baud rate generator |
| TXSTAbits.BRGH = 1; // High baud rate select |
| |
| TXSTAbits.SYNC = 0; // Async operation |
| RCSTAbits.CREN = 1; // Enable reception module |
| TXSTAbits.TXEN = 1; // Enable transmission module |
| RCSTAbits.SPEN = 1; // Enable EUSART module |
| |
| PIE1bits.RCIE = 1; // UART RX interrupt starts enabled |
| PIE1bits.TXIE = 0; // UART TX interrupt starts disabled |
| |
| // Initialize local variables |
| data_ptr->buffer_in_read_ind = 0; |
| data_ptr->buffer_in_write_ind = 0; |
| data_ptr->buffer_in_len = 0; |
| data_ptr->buffer_out_ind = 0; |
| data_ptr->buffer_out_len = 0; |
| } |
| |
| void UART_TX_Interrupt_Handler(void) { |
| // Send more data when transmit buffer is empty |
| if (data_ptr->buffer_out_ind != data_ptr->buffer_out_len) { |
| TXREG = data_ptr->buffer_out[data_ptr->buffer_out_ind]; |
| data_ptr->buffer_out_ind++; |
| } else { |
| // Stop processing TX interrupts if there is no more data to send |
| while (!TXSTAbits.TRMT); |
| PIE1bits.TXIE = 0; |
| data_ptr->buffer_out_ind = 0; |
| data_ptr->buffer_out_len = 0; |
| } |
| } |
| |
| void UART_RX_Interrupt_Handler(void) { |
| char c = RCREG; |
| |
| // Read received data into buffer |
| data_ptr->buffer_in[data_ptr->buffer_in_write_ind] = c; |
| if (data_ptr->buffer_in_write_ind == UART_BUFFER_SIZE - 1) { |
| data_ptr->buffer_in_write_ind = 0; |
| } else { |
| data_ptr->buffer_in_write_ind++; |
| } |
| |
| // Increment read counter to keep only the latest data |
| if (data_ptr->buffer_in_len < UART_BUFFER_SIZE) { |
| data_ptr->buffer_in_len++; |
| } else { |
| if (data_ptr->buffer_in_read_ind == UART_BUFFER_SIZE - 1) { |
| data_ptr->buffer_in_read_ind = 0; |
| } else { |
| data_ptr->buffer_in_read_ind++; |
| } |
| } |
| |
| // Reset receiver module on overrun error |
| if (RCSTAbits.OERR == 1) { |
| RCSTAbits.CREN = 0; |
| RCSTAbits.CREN = 1; |
| } |
| } |
| |
| void UART_Write(char *data, char length) { |
| // Ensure that no transmission is currently running |
| while (PIE1bits.TXIE); |
| |
| data_ptr->buffer_out_len = length; |
| data_ptr->buffer_out_ind = 0; |
| for (char i = 0; i < length; i++) { |
| data_ptr->buffer_out[i] = data[i]; |
| } |
| |
| // Start transmission |
| PIE1bits.TXIE = 1; |
| } |
| |
| char UART_Read(char *buffer) { |
| PIE1bits.RCIE = 0; // Disable receiver interrupt |
| char length = data_ptr->buffer_in_len; |
| for (char i = 0; i < length; i++) { |
| buffer[i] = data_ptr->buffer_in[data_ptr->buffer_in_read_ind]; |
| if (data_ptr->buffer_in_read_ind == UART_BUFFER_SIZE - 1) { |
| data_ptr->buffer_in_read_ind = 0; |
| } else { |
| data_ptr->buffer_in_read_ind++; |
| } |
| } |
| data_ptr->buffer_in_len -= length; |
| PIE1bits.RCIE = 1; // Re-enable receiver interrupt |
| return length; |
| } |