256 lines
6.4 KiB
C
256 lines
6.4 KiB
C
/* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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*/
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#include <stdint.h> // Standard Integer Types
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#include <stdio.h> // Standard IO facilities
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#include <stdlib.h> // General utilities
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#include <stdbool.h> // Boolean
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#include <string.h> // Strings
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#include <avr/io.h> // AVR device-specific IO definitions
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#include <util/delay.h> // Convenience functions for busy-wait delay loops
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#include <avr/interrupt.h> // Interrupts
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#include <avr/wdt.h> // Watchdog timer handling
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#include <avr/pgmspace.h> // Program Space Utilities
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#include <avr/sleep.h> // Power Management and Sleep Modes
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#include "uart.h" // basic UART functions
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#include "main.h" // main definitions
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/* help strings */
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const char help_00[] PROGMEM = "commands:\n";
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const char help_01[] PROGMEM = "\thelp display this help\n";
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const char help_02[] PROGMEM = "\tled on|off|toggle change LED state\n";
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const char help_03[] PROGMEM = "\tread [B-D][0-7] read value from pin\n";
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const char help_04[] PROGMEM = "\twrite [B-D][0-7] 0|1 write value on pin\n";
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PGM_P const help_table[] PROGMEM = {
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help_00,
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help_01,
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help_02,
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help_03,
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help_04
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};
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/* global variables */
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char uart_in[32] = {0}; // user input from USART
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volatile uint8_t uart_in_i = 0; // how many UART characters have been input
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/* flags, set in the interrupts and handled in the main program */
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volatile bool uart_flag = false; // UART input data is available
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/* switch off LED */
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void led_off(void)
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{
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LED_PORT &= ~(1<<LED_IO); // remove power to LED
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}
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/* switch on LED */
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void led_on(void)
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{
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LED_PORT |= (1<<LED_IO); // provide power to LED
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}
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/* toggle LED */
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void led_toggle(void)
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{
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LED_PIN |= (1<<LED_IO);
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}
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void help(void)
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{
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char* str;
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for (uint8_t i=0; i<sizeof(help_table)/sizeof(PGM_P); i++) { /* display all help lines */
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str = malloc(strlen_PF((uint_farptr_t)pgm_read_word(&(help_table[i]))));
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strcpy_PF(str, (uint_farptr_t)pgm_read_word(&(help_table[i])));
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printf(str);
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free(str);
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}
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}
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/* save the UART input into a string */
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ISR(USART_RX_vect) { /* UART receive interrupt */
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uart_in[uart_in_i] = getchar(); // save input
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if (uart_in_i<sizeof(uart_in)-1) { // go to next if there is space left (else overwrite last)
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uart_in_i++; // prepare for next character
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uart_in[uart_in_i] = 0; // always end the string
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}
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uart_flag = true; // notify new character is there
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}
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/* disable watchdog when booting */
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void wdt_init(void) __attribute__((naked)) __attribute__((section(".init3")));
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void wdt_init(void)
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{
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MCUSR = 0;
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wdt_disable();
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return;
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}
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/* initialize GPIO */
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void io_init(void)
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{
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/* use UART as terminal */
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uart_init();
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stdout = &uart_output;
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stdin = &uart_input;
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/* gpio */
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/* LED */
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LED_DDR |= (1<<LED_IO); // LED is driven by pin (set as output)
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led_off();
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sei(); /* enable interrupts */
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}
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/* process command */
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void command_action()
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{
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/* split command */
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const char* delimiter = " ";
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char* word = strtok(uart_in,delimiter);
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if (!word) {
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goto error;
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}
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/* parse command */
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if (0==strcmp(word,"help")) {
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help();
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} else if (0==strcmp(word,"led")) {
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/* expecting state */
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word = strtok(NULL,delimiter);
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if (!word) {
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goto error;
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}
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if (0==strcmp(word,"on")) {
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led_on();
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} else if (0==strcmp(word,"off")) {
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led_off();
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} else if (0==strcmp(word,"toggle")) {
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led_toggle();
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} else {
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goto error;
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}
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} else if (0==strcmp(word,"read")) {
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/* expecting pin */
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word = strtok(NULL,delimiter);
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if (!word) {
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goto error;
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}
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if (2==strlen(word) && word[0]>='B' && word[0]<='D' && word[1]>='0' && word[1]<='7') {
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volatile uint8_t * pin = NULL;
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volatile uint8_t * ddr = NULL;
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switch (word[0]) {
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case 'B':
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pin = &PINB;
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ddr = &DDRB;
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break;
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case 'C':
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pin = &PINC;
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ddr = &DDRC;
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break;
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case 'D':
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pin = &PIND;
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ddr = &DDRD;
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break;
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}
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*ddr &= ~(1<<(word[1]-'0')); // set as input
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printf("%s: %u\n", word, (*pin>>(word[1]-'0'))&0x1); // print value
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} else {
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goto error;
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}
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} else if (0==strcmp(word,"write")) {
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/* expecting pin */
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word = strtok(NULL,delimiter);
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if (!word) {
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goto error;
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}
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if (2==strlen(word) && word[0]>='B' && word[0]<='D' && word[1]>='0' && word[1]<='7') {
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uint8_t pin = word[1]-'0';
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volatile uint8_t * port = NULL;
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volatile uint8_t * ddr = NULL;
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switch (word[0]) {
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case 'B':
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port = &PORTB;
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ddr = &DDRB;
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break;
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case 'C':
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port = &PORTC;
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ddr = &DDRC;
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break;
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case 'D':
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port = &PORTD;
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ddr = &DDRD;
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break;
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}
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*ddr |= (1<<pin); // set as output
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/* expecting value */
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word = strtok(NULL,delimiter);
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if (!word || strlen(word)!=1) {
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goto error;
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}
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/* write value */
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if ('0'==word[0]) {
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*port &= ~(1<<pin);
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} else if ('1'==word[0]) {
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*port |= (1<<pin);
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} else {
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goto error;
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}
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} else {
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goto error;
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}
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} else {
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goto error;
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}
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return;
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error:
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printf(PSTR("command not recognized\n"));
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return;
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}
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int main(void)
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{
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uint8_t uart_out_i = 0; // how many UART input characters have been processed
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io_init(); // initialize IOs
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printf(PSTR("welcome to the demo code\n"));
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while (true) { // endless loop for micro-controller
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while (uart_flag) { // new UART input
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uart_flag = false;
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while (uart_out_i<uart_in_i) {
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putchar(uart_in[uart_out_i++]); // print current character
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}
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if ('\n'==uart_in[uart_in_i-1] || '\r'==uart_in[uart_in_i-1]) { // end of line detected
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if ('\r'==uart_in[uart_in_i-1]) { // be sure to print a newline (for windows and mac EOL)
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putchar('\n');
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}
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uart_in[uart_in_i-1] = 0; // remove end of line
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if (uart_in_i>1) { // ignore empty lines
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command_action(); // process command
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}
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uart_out_i = 0; // reset output
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uart_in_i = 0; // reset input
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}
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}
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/* go to sleep and wait for next interrupt */
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set_sleep_mode(SLEEP_MODE_IDLE);
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sleep_mode();
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}
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return 0;
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}
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