Implement handling of button presses

I did changes to apps/main_clock as this app is also used for testing new
features.

6 files changed, 102 insertions, 5 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0b849c3..e9e2c8b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -31,7 +31,10 @@ add_executable(pico-watch
 	pico-watch.c
         init.c
         init.h
+        buttons.c
+        buttons.h
         apps/main_clock.c
+        apps/main_clock.h
 	)
 
 pico_set_program_name(pico-watch "pico-watch")
diff --git a/apps/main_clock.c b/apps/main_clock.c
index ec95585..496c696 100644
--- a/apps/main_clock.c
+++ b/apps/main_clock.c
@@ -5,6 +5,7 @@
 #include "../oled/ss_oled.h"
 
 #include "main_clock.h"
+#include "../buttons.h"
 
 // Time as string
 // Adapted from pico-sdk/scr/common/pico_util/datetime.c
@@ -51,15 +52,33 @@ void show_datetime(SSOLED *oled) {
 }
 
 int main_clock_render(SSOLED *oled, char *data, uint data_size) {
+    oledWriteString(oled, 0,15,0, (char *)"Test clock", FONT_8x8, 0, 1);
     show_datetime(oled);
-//    data[1] += 1; // testing
-//    oledWriteString(oled, 0,0,2, &data[0], FONT_6x8, 0, 1);
+    oledWriteString(oled, 0,0,0, &data[0], FONT_6x8, 0, 1);
+    return 0;
+}
+
+// Example of how button inputs could be interpreted.
+// Drawing on screen should be done in the render function.
+int main_clock_btnpressed(SSOLED *oled, char *data, uint data_size, uint gpio) {
+    switch (gpio) {
+        case BUTTON_HOME: // Apps will generally not receive the Home button press
+            data[0] = 'H'; break;
+        case BUTTON_SELECT:
+            data[0] = 'S'; break;
+        case BUTTON_MODE:
+            data[0] = 'M'; break;
+        case BUTTON_DOWN:
+            data[0] = 'D'; break;
+        case BUTTON_UP:
+            data[0] = 'U'; break;
+        default:
+            data[0] = '?';
+    }
     return 0;
 }
 
 int main_clock_init(SSOLED *oled, char *data, uint data_size) {
-//    data[0] = 'a'; // testing, to showcase the use of data
-//    data[1] = 'b';
     return 1; // return 1 when function not implemented
 }
 
diff --git a/apps/main_clock.h b/apps/main_clock.h
index d47e837..a7acdfe 100644
--- a/apps/main_clock.h
+++ b/apps/main_clock.h
@@ -10,6 +10,7 @@ void show_datetime(SSOLED *oled);
 
 int main_clock_init(SSOLED *oled, char *data, uint data_size);
 int main_clock_render(SSOLED *oled, char *data, uint data_size);
+int main_clock_btnpressed(SSOLED *oled, char *data, uint data_size, uint gpio);
 int main_clock_bgrefresh(SSOLED *oled, char *data, uint data_size);
 int main_clock_destroy(SSOLED *oled, char *data, uint data_size);
 
diff --git a/buttons.c b/buttons.c
new file mode 100644
index 0000000..2e9996b
--- /dev/null
+++ b/buttons.c
@@ -0,0 +1,49 @@
+#include <stdio.h>
+#include "pico/stdlib.h"
+
+#include "buttons.h"
+extern int app_btnpressed(int app_id, uint gpio);
+extern int current_app;
+
+// Debounce control
+// See https://www.raspberrypi.org/forums/viewtopic.php?f=145&t=301522#p1812063
+// time is currently shared between all buttons.
+unsigned long button_time;
+const int button_delayTime = 50; // 50ms worked fine for me .... change it to your needs/specs.
+
+//const uint BUTTON_PINS[] = {BUTTON_HOME, BUTTON_SELECT, BUTTON_MODE, BUTTON_UP, BUTTON_DOWN};
+
+void gpio_interrupt_cb(uint gpio, uint32_t events) {
+    if ((to_ms_since_boot(get_absolute_time())-button_time)>button_delayTime) {
+        app_btnpressed(current_app, gpio);
+        button_time = to_ms_since_boot(get_absolute_time());
+    }
+}
+
+void init_buttons() {
+    gpio_init(BUTTON_HOME);
+    gpio_pull_up(BUTTON_HOME);
+    gpio_set_irq_enabled_with_callback(BUTTON_HOME, GPIO_IRQ_EDGE_FALL , true, &gpio_interrupt_cb);
+    gpio_init(BUTTON_SELECT);
+    gpio_pull_up(BUTTON_SELECT);
+    gpio_set_irq_enabled_with_callback(BUTTON_SELECT, GPIO_IRQ_EDGE_FALL , true, &gpio_interrupt_cb);
+    gpio_init(BUTTON_MODE);
+    gpio_pull_up(BUTTON_MODE);
+    gpio_set_irq_enabled_with_callback(BUTTON_MODE, GPIO_IRQ_EDGE_FALL , true, &gpio_interrupt_cb);
+    gpio_init(BUTTON_DOWN);
+    gpio_pull_up(BUTTON_DOWN);
+    gpio_set_irq_enabled_with_callback(BUTTON_DOWN, GPIO_IRQ_EDGE_FALL , true, &gpio_interrupt_cb);
+    gpio_init(BUTTON_UP);
+    gpio_pull_up(BUTTON_UP);
+    gpio_set_irq_enabled_with_callback(BUTTON_UP, GPIO_IRQ_EDGE_FALL , true, &gpio_interrupt_cb);
+
+    /* For some reason for loop does not work… TODO
+    for (int i=0; i == NUMBER_OF_BUTTONS; i++) {
+        uint button = BUTTON_PINS[i];
+        gpio_init(button);
+        gpio_pull_up(button);
+        gpio_set_irq_enabled_with_callback(button, GPIO_IRQ_EDGE_FALL , true, &gpio_interrupt_cb);
+    }
+    */
+    button_time = to_ms_since_boot(get_absolute_time());
+}
diff --git a/buttons.h b/buttons.h
new file mode 100644
index 0000000..756c849
--- /dev/null
+++ b/buttons.h
@@ -0,0 +1,19 @@
+#ifndef __BUTTONS_H__
+#define __BUTTONS_H__
+#include <stdio.h>
+
+// Init buttons used in conjuction with interrupts
+// All buttons are connected to ground.
+#define NUMBER_OF_BUTTONS 5
+#define BUTTON_HOME 22
+#define BUTTON_SELECT 18
+#define BUTTON_MODE 19
+#define BUTTON_DOWN 20
+#define BUTTON_UP 21
+unsigned long button_time;
+const int button_delayTime;
+
+void init_buttons();
+void gpio_interrupt_cb(uint gpio, uint32_t events);
+
+#endif
\ No newline at end of file
diff --git a/pico-watch.c b/pico-watch.c
index a7c3886..eb5f7cc 100644
--- a/pico-watch.c
+++ b/pico-watch.c
@@ -6,6 +6,7 @@
 #include "oled/ss_oled.h"
 
 #include "init.h"
+#include "buttons.h"
 #include "apps/main_clock.h"
 
 int current_app = 0;
@@ -14,6 +15,7 @@ int current_app = 0;
 #define APP_DATA_BUFFER_LEN 256
 int (*APPS_FUNC_INIT[NUMBER_OF_APPS])(SSOLED *oled, char *data, uint data_size) = {main_clock_init};
 int (*APPS_FUNC_RENDER[NUMBER_OF_APPS])(SSOLED *oled, char *data, uint data_size) = {main_clock_render};
+int (*APPS_FUNC_BTNPRESS[NUMBER_OF_APPS])(SSOLED *oled, char *data, uint data_size, uint gpio) = {main_clock_btnpressed};
 int (*APPS_FUNC_BGREFRESH[NUMBER_OF_APPS])(SSOLED *oled, char *data, uint data_size) = {main_clock_bgrefresh};
 int (*APPS_FUNC_DESTROY[NUMBER_OF_APPS])(SSOLED *oled, char *data, uint data_size) = {main_clock_destroy};
 char APPS_DATA[NUMBER_OF_APPS][APP_DATA_BUFFER_LEN];
@@ -29,6 +31,10 @@ int app_render(int app_id) {
     return (*APPS_FUNC_RENDER[app_id])(&oled, &APPS_DATA[app_id][0], sizeof(APPS_DATA[app_id]));
 }
 
+int app_btnpressed(int app_id, uint gpio) {
+    return (*APPS_FUNC_BTNPRESS[app_id])(&oled, &APPS_DATA[app_id][0], sizeof(APPS_DATA[app_id]), gpio);
+}
+
 int app_destroy(int app_id) {
     if (APPS_IS_INIT[app_id])
         return (*APPS_FUNC_INIT[app_id])(&oled, &APPS_DATA[app_id][0], sizeof(APPS_DATA[app_id]));
@@ -36,10 +42,10 @@ int app_destroy(int app_id) {
 
 int main() {
     init_all();
+    init_buttons();
 
     app_init(current_app);
 
-    oledWriteString(&oled, 0,15,0, (char *)"Test clock", FONT_8x8, 0, 1);
     while (1) {
         app_render(current_app);
         sleep_ms(500);