121 lines
3.2 KiB
C
121 lines
3.2 KiB
C
#include "header.h"
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// MACROS
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// USART
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#define USART_BAUDRATE 115200
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#define INPUT_SIZE 7
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// GLOBAL VARIABLES
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volatile char color_input[INPUT_SIZE + 1] = {0};
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volatile int input_index = 0;
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//
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// FUNCTIONS
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//
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void uart_init() {
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UBRR0H = (unsigned char) (BAUD_PRESCALER(USART_BAUDRATE) >> 8); // 20.11.5 : UBRRnL and UBRRnH – USART Baud Rate Registers
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UBRR0L = (unsigned char) BAUD_PRESCALER(USART_BAUDRATE);
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UCSR0C |= ASYNCHRONOUS | PARITY_DISABLED | STOP_ONE_BIT | DATA_EIGHT_BIT; // 20.11.4 : set Frame Format
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UCSR0B |= RECEIVER_ENABLED | TRANSMITTER_ENABLED | INTERRUPT_RECEIVER_ENABLED; // 20.11.3 : enable Receiver and Transmitter, and interrupt on receiver
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SREG |= ENABLE_GLOBAL_INTERRUPT; // 7.3.1 : Status Register, bit 7 : I – Global Interrupt Enable
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}
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char uart_rx(void) {
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while (TEST(UCSR0A, RXC0) == 0); // 20.11.2 : do nothing until there are unread data in the receive buffer (UDRn), (RXCn flag in UCSRnA register set to 1 when buffer has data)
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return UDR0; // 20.11.1 : get data in buffer, UDRn – USART I/O Data Register (read and write)
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}
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void uart_tx(char c) {
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while (TEST(UCSR0A, UDRE0) == 0); // 20.11.2 : do nothing until UDRn buffer is empty, (UDREn flag in UCSRnA register set to 1 when buffer empty)
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UDR0 = (unsigned char) c; // 20.11.1 : Put data into buffer, UDRn – USART I/O Data Register (read and write)
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}
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// void uart_printstr(const char* str) {
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// while (*str) {
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// uart_tx(*str);
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// str++;
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// }
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// }
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ISR(USART_RX_vect) { // Table 12-7 : we select the code for USART Receive
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char received_char = UDR0; // read received character
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if (received_char == '\b' || received_char == 127) { // if backspace is received
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if (input_index <= 0) {
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return;
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}
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if (input_index >= INPUT_SIZE) {
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return;
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}
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remove_last_character();
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input_index--;
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uart_tx('\b'); // Move cursor back
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uart_tx(' '); // Erase the character on screen
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uart_tx('\b'); // Move cursor back again
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} else if (received_char == '\n' || received_char == '\r') { // if enter is received
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if (input_index != INPUT_SIZE) {
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return;
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}
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set_color((char *)color_input);
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reset_input();
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} else { // any other character
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if (input_index >= INPUT_SIZE) {
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return;
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}
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if (!is_valid_color_input(received_char)) {
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return;
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}
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fill_str(received_char);
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uart_tx(received_char);
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input_index++;
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}
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}
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int is_valid_color_input(char c) {
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if (input_index == 0) {
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if (c == '#') {
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return TRUE;
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} else {
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return FALSE;
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}
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}
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if (input_index >= INPUT_SIZE) {
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return FALSE;
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}
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if (c >= '0' && c <= '9') {
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return TRUE;
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} else if (c >= 'A' && c <= 'F') {
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return TRUE;
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} else if (c >= 'a' && c <= 'f') {
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return TRUE;
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}
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return FALSE;
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}
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void fill_str(char input) {
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if (input_index >= INPUT_SIZE) {
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return;
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}
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color_input[input_index] = input;
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}
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void remove_last_character() {
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color_input[input_index] = 0;
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}
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int strlength(volatile char *str) {
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int length = 0;
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while (*str) {
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length++;
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str++;
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}
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return length;
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}
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void reset_input() {
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for(int i = 0; i < INPUT_SIZE; i++) {
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color_input[i] = 0;
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}
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uart_tx('\r');
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uart_tx('\n');
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input_index = 0;
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} |