Make button.c and button.h

Makefile

@@ -1,8 +1,8 @@
 CC=clang
-CFLAGS=-std=c99
+CFLAGS=-std=c99 -Wall
 LD=clang
 LDFLAGS=-lgpio -lfigpar
-SRCS=src/main.c src/util.c src/lcd.c src/ths.c
+SRCS=src/main.c src/util.c src/lcd.c src/ths.c src/button.c
 PROG=rpi4b-temp-humidity
 
 .include "config.mk"
@@ -11,9 +11,10 @@ OBJS=${SRCS:C/^src/bin/:C/.c$/.o/}
 bin/${PROG}: ${OBJS}
 	${LD} ${LDFLAGS} -o ${@} ${OBJS}
 
-main.o util.o lcd.o ths.o: util.h
+main.o util.o lcd.o ths.o button.o: util.h
 main.o lcd.o: lcd.h
 main.o ths.o: ths.h
+main.o button.o: button.h
 
 ${OBJS}: ${.TARGET:C/^bin/src/:C/.o$/.c/}
 	@mkdir -p bin/
@@ -25,6 +26,7 @@ ${OBJS}: ${.TARGET:C/^bin/src/:C/.o$/.c/}
 -DDEFAULT_FAIL_KEY="\"${DEFAULT_FAIL_KEY}\""\
 -DDEFAULT_FAIL_LIMIT="${DEFAULT_FAIL_LIMIT}"\
 -DDEFAULT_LCD_VERSION="\"${DEFAULT_LCD_VERSION}\""\
+-DDEFAULT_REFRESH_TIME="${DEFAULT_REFRESH_TIME}"\
 -o ${@} ${.ALLSRC}
 
 clean:

config.mk

@@ -2,7 +2,7 @@ DEFAULT_CONFIG_PATH=config.conf
 DEFAULT_GPIO_DEVICE=/dev/gpioc0
 DEFAULT_TEMP_KEY=dev.gpioths.0.temperature
 DEFAULT_HUMID_KEY=dev.gpioths.0.humidity
-#DEFAULT_FAIL_KEY=dev.gpioths.0.fails
+DEFAULT_FAIL_KEY=dev.gpioths.0.fails
-DEFAULT_FAIL_KEY=
 DEFAULT_FAIL_LIMIT=5
 DEFAULT_LCD_VERSION=jp
+DEFAULT_REFRESH_TIME=5000

src/button.c

@@ -0,0 +1,59 @@
+/*
+ * button.c - Call functions if GPIO pins are high
+ * Copyright (C) 2024  Alexander Rosenberg
+ *
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later
+ * version. See the LICENSE file for more information.
+ */
+#include "button.h"
+#include "util.h"
+
+#include <sys/time.h>
+
+static const struct timespec DEBOUNCE_TIME = {
+    .tv_sec = 0,
+    .tv_nsec = 10 * 1000 * 1000, // 10ms
+};
+
+Button *button_new(gpio_handle_t handle, gpio_pin_t pin, ButtonAction action,
+                   void *user_data) {
+    Button *button = malloc_checked(sizeof(Button));
+    button->handle = handle;
+    button->pin = pin;
+    gpio_config_t cfg = {
+        .g_pin = pin,
+        .g_flags = GPIO_PIN_INPUT | GPIO_PIN_PULLUP,
+    };
+    gpio_pin_set_flags(handle, &cfg);
+    button->action = action;
+    button->user_data = user_data;
+    button->is_down = false;
+    timespecclear(&button->last_detect);
+    return button;
+}
+
+void button_delete(Button *button) {
+    free(button);
+}
+
+int button_dispatch(Button *button) {
+    struct timespec cur_time, diff_time;
+    clock_gettime(CLOCK_UPTIME, &cur_time);
+    timespecsub(&cur_time, &button->last_detect, &diff_time);
+    if (timespeccmp(&diff_time, &DEBOUNCE_TIME, >=)) {
+        gpio_value_t status = gpio_pin_get(button->handle, button->pin);
+        if (!button->is_down && status == GPIO_PIN_LOW) {
+            button->is_down = true;
+            button->last_detect= cur_time;
+            if (button->action) {
+                return button->action(button->user_data);
+            }
+        } else if (button->is_down && status == GPIO_PIN_HIGH) {
+            button->last_detect = cur_time;
+            button->is_down = false;
+        }
+    }
+    return 0;
+}

src/button.h

@@ -0,0 +1,51 @@
+/*
+ * button.h - Call functions if GPIO pins are high
+ * Copyright (C) 2024  Alexander Rosenberg
+ *
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later
+ * version. See the LICENSE file for more information.
+ */
+#ifndef INCLUDED_BUTTON_H
+#define INCLUDED_BUTTON_H
+
+#include <sys/types.h>
+#include <libgpio.h>
+#include <stdbool.h>
+
+typedef int(*ButtonAction)(void *);
+
+typedef struct {
+    gpio_handle_t handle;
+    gpio_pin_t pin;
+    ButtonAction action;
+    void *user_data;
+
+    struct timespec last_detect;
+    bool is_down;
+} Button;
+
+/*
+ * Create a Button object with the given HANDLE, PIN and ACTION. USER_DATA will
+ * be passed to ACTION every time it is run. It is up to the caller to free
+ * USER_DATA when the Button is freed.
+ * Return: the created Button.
+ */
+Button *button_new(gpio_handle_t uandle, gpio_pin_t pin, ButtonAction action,
+                   void *user_data);
+
+/*
+ * Delete BUTTON.
+ * NOTE: This does NOT free USER_DATA.
+ */
+void button_delete(Button *button);
+
+/*
+ * Check if the pin for this button is HIGH, if it is, call ACTION and prevent
+ * it from being called again until button becomes LOW.
+ * Return: 0 if nothing is done, otherwise, the return value of ACTION.
+ */
+int button_dispatch(Button *button);
+
+#endif

src/main.c

@@ -10,18 +10,18 @@
 #include "lcd.h"
 #include "util.h"
 #include "ths.h"
+#include "button.h"
 
 #include <unistd.h>
 #include <err.h>
 #include <errno.h>
 #include <stdio.h>
-#include <sys/sysctl.h>
 #include <string.h>
+#include <ctype.h>
 #include <figpar.h>
 #include <inttypes.h>
-#include <ctype.h>
-#include <sys/sysctl.h>
 #include <time.h>
+#include <sys/time.h>
 #include <unistd.h>
 
 /*
@@ -40,6 +40,7 @@ void parse_config_file(const char *path);
 int main(int argc, char *const *argv) {
     parse_arguments(argc, argv);
     parse_config_file(GLOBAL_OPTS.config_path);
+
     gpio_handle_t handle = gpio_open_device(GLOBAL_OPTS.gpio_path);
     if (handle == GPIO_INVALID_HANDLE) {
         err(1, "could not open GPIO device \"%s\"", GLOBAL_OPTS.gpio_path);
@@ -57,7 +58,17 @@ int main(int argc, char *const *argv) {
     if (!GLOBAL_OPTS.fail_key) {
         warnx("it's probably a bad idea to not set fail_key");
     }
+    struct timespec last_update, cur_time, diff_time;
+    timespecclear(&last_update);
+    struct timespec refresh_time = {
+        .tv_sec = GLOBAL_OPTS.refresh_time / 1000,
+        .tv_nsec = (GLOBAL_OPTS.refresh_time % 1000) * 1000 * 1000,
+    };
+    Button *btn = button_new(handle, 23, (ButtonAction) printf, "Button Pressed!\n");
     while (true) {
+        clock_gettime(CLOCK_UPTIME, &cur_time);
+        timespecsub(&cur_time, &last_update, &diff_time);
+        if (timespeccmp(&diff_time, &refresh_time, >=)) {
             if (GLOBAL_OPTS.fail_key && ths_read_fails(ths) > GLOBAL_OPTS.fail_limit) {
                 errx(1, "THS fail limit reached");
             }
@@ -66,15 +77,21 @@ int main(int argc, char *const *argv) {
             char buff[17];
             int cur_len = snprintf(buff, sizeof(buff), "%4.1fF %3" PRIu32 "%% ",
                                    DK_TO_F(ths_read_temp(ths)), ths_read_humid(ths));
-        time_t it = time(NULL);
             struct tm lt;
-        localtime_r(&it, &lt);
+            localtime_r(&cur_time.tv_sec, &lt);
             strftime(buff + cur_len, sizeof(buff) - cur_len,
                     "%H:%M", &lt);
             lcd_move_to(lcd, 1, 0);
             lcd_write_string(lcd, buff);
-        usleep(1000 * 1000 * 5);
+            LOG_VERBOSE("Temp. and humid. display updated\n");
+            last_update = cur_time;
         }
+        button_dispatch(btn);
+        // 10ms is probably faster than anyone will press a button
+        usleep(10 * 1000);
+    }
+    button_delete(btn);
+    ths_close(ths);
     lcd_close(lcd);
     gpio_close(handle);
     cleanup_options(&GLOBAL_OPTS);
@@ -250,6 +267,8 @@ static void set_options_from_entries(struct figpar_config *entries,
     entries[9].type = FIGPAR_TYPE_NONE;
     GLOBAL_OPTS.lcd_version = entries[9].value.str;
     LOG_VERBOSE("Using lcd_version: \"%s\"\n", GLOBAL_OPTS.lcd_version);
+
+    GLOBAL_OPTS.refresh_time = entries[10].value.u_num;
 }
 
 void parse_config_file(const char *path) {
@@ -311,6 +330,12 @@ void parse_config_file(const char *path) {
             .action = parse_str_callback,
             .value = {.str = strdup_checked(DEFAULT_LCD_VERSION)},
         },
+        {
+            .directive = "refresh_time",
+            .type = FIGPAR_TYPE_UINT,
+            .action = parse_uint_callback,
+            .value = {.u_num = DEFAULT_REFRESH_TIME},
+        },
         { .directive = NULL },
     };
     size_t entry_count = sizeof(entries) / sizeof(struct figpar_config);

src/util.h

@@ -33,6 +33,7 @@ typedef struct {
     char *humid_key; // sysctl key for humidity
     char *fail_key; // sysctl key for number of fails
     uint32_t fail_limit; // limit for number of failures before exit
+    uint32_t refresh_time; // time between temp and humid refresh
 } Options;
 extern Options GLOBAL_OPTS;