Sonoff Basic PWM example (#50)

.gitignore

@@ -1 +1,5 @@
 /wifi.h
+/examples/*/wifi.h
+/examples/*/build
+/examples/*/firmware
+.DS_Store

examples/sonoff_basic_pwm/Makefile

@@ -0,0 +1,21 @@
+PROGRAM = sonoff_basic_dimmer
+
+EXTRA_COMPONENTS = \
+	extras/http-parser \
+	extras/dhcpserver \
+	$(abspath ../../components/wifi_config) \
+	$(abspath ../../components/wolfssl) \
+	$(abspath ../../components/cJSON) \
+	$(abspath ../../components/homekit)
+
+FLASH_SIZE ?= 8
+FLASH_MODE ?= dout
+FLASH_SPEED ?= 40
+HOMEKIT_SPI_FLASH_BASE_ADDR ?= 0x7A000
+
+EXTRA_CFLAGS += -I../.. -DHOMEKIT_SHORT_APPLE_UUIDS
+
+include $(SDK_PATH)/common.mk
+
+monitor:
+	$(FILTEROUTPUT) --port $(ESPPORT) --baud 115200 --elf $(PROGRAM_OUT)

examples/sonoff_basic_pwm/button.c

@@ -0,0 +1,109 @@
+#include <string.h>
+#include <esplibs/libmain.h>
+#include "button.h"
+
+typedef struct _button {
+    uint8_t gpio_num;
+    button_callback_fn callback;
+
+    uint16_t debounce_time;
+    uint16_t long_press_time;
+
+    bool pressed_value;
+
+    uint32_t last_press_time;
+    uint32_t last_event_time;
+
+    struct _button *next;
+} button_t;
+
+
+button_t *buttons = NULL;
+
+
+static button_t *button_find_by_gpio(const uint8_t gpio_num) {
+    button_t *button = buttons;
+    while (button && button->gpio_num != gpio_num)
+        button = button->next;
+
+    return button;
+}
+
+
+void button_intr_callback(uint8_t gpio) {
+    button_t *button = button_find_by_gpio(gpio);
+    if (!button)
+        return;
+
+    uint32_t now = xTaskGetTickCountFromISR();
+    if ((now - button->last_event_time)*portTICK_PERIOD_MS < button->debounce_time) {
+        // debounce time, ignore events
+        return;
+    }
+    button->last_event_time = now;
+    if (gpio_read(button->gpio_num) == button->pressed_value) {
+        // Record when the button is pressed down.
+        button->last_press_time = now;
+    } else {
+        // The button is released. Handle the use cases.
+        if ((now - button->last_press_time) * portTICK_PERIOD_MS > button->long_press_time) {
+            button->callback(button->gpio_num, button_event_long_press);
+        } else {
+            button->callback(button->gpio_num, button_event_single_press);
+        }
+    }
+}
+
+int button_create(const uint8_t gpio_num, bool pressed_value, uint16_t long_press_time, button_callback_fn callback) {
+    button_t *button = button_find_by_gpio(gpio_num);
+    if (button)
+        return -1;
+
+    button = malloc(sizeof(button_t));
+    memset(button, 0, sizeof(*button));
+    button->gpio_num = gpio_num;
+    button->callback = callback;
+    button->pressed_value = pressed_value;
+
+    // times in milliseconds
+    button->debounce_time = 50;
+    button->long_press_time = long_press_time;
+
+    uint32_t now = xTaskGetTickCountFromISR();
+    button->last_event_time = now;
+    button->last_press_time = now;
+
+    button->next = buttons;
+    buttons = button;
+
+    gpio_set_pullup(button->gpio_num, true, true);
+    gpio_set_interrupt(button->gpio_num, GPIO_INTTYPE_EDGE_ANY, button_intr_callback);
+
+    return 0;
+}
+
+
+void button_delete(const uint8_t gpio_num) {
+    if (!buttons)
+        return;
+
+    button_t *button = NULL;
+    if (buttons->gpio_num == gpio_num) {
+        button = buttons;
+        buttons = buttons->next;
+    } else {
+        button_t *b = buttons;
+        while (b->next) {
+            if (b->next->gpio_num == gpio_num) {
+                button = b->next;
+                b->next = b->next->next;
+                break;
+            }
+        }
+    }
+
+    if (button) {
+        gpio_set_interrupt(gpio_num, GPIO_INTTYPE_EDGE_ANY, NULL);
+    }
+}
+

examples/sonoff_basic_pwm/button.h

@@ -0,0 +1,26 @@
+#pragma once
+
+typedef enum {
+    button_event_single_press,
+    button_event_long_press,
+} button_event_t;
+
+typedef void (*button_callback_fn)(uint8_t gpio_num, button_event_t event);
+
+/** 
+    Starts monitoring the given GPIO pin for the pressed value. Events are recieved through the callback.
+
+    @param gpio_num The GPIO pin that should be monitored
+    @param pressed_value The expected value when the button is pressed. For buttons connected to ground this is 0/false, for other buttons this might be 1/true.
+    @param long_press_time The duration that should be recognized as a long press, in miliseconds.
+    @param callback The callback that is called when an "button" event occurs.
+    @return A negative integer if this method fails.
+*/
+int button_create(uint8_t gpio_num, bool pressed_value, uint16_t long_press_time, button_callback_fn callback);
+
+/** 
+    Removes the given GPIO pin from monitoring.
+
+    @param gpio_num The GPIO pin that should be removed from monitoring
+*/
+void button_delete(uint8_t gpio_num);

examples/sonoff_basic_pwm/info.txt

@@ -0,0 +1,7 @@
+Modification of sonoff_basic_toggle example with PWM dimming as implemented in eps-open-rtos/examples/pwm_test.c
+
+IMPORTANT: This is a proof of concept demonstration and should NOT be modified to attempt to control AC directly via PWM to the relay or by swapping out the relay for TRIAC!
+
+Indirect approach needed to dim AC i.e. via separate daughter board with a TRIAC and zero-crossing detection circuit. Zero crossing detection facilitates synchronise of the PWM with the AC to stop flickering. Google "ac dimming" for more information.
+
+