From 28541d3222f672a6fab7d332bffae09d5f8d5f35 Mon Sep 17 00:00:00 2001
From: fastium <fastium.pro@proton.me>
Date: Sat, 6 Jun 2026 11:18:58 +0200
Subject: [PATCH] feat(MP/daemon): display on oled

---
 src/06-mini-project/daemon/oled/oled.c | 92 +++++++++++++++++++++-----
 src/06-mini-project/daemon/oled/oled.h | 22 ++++--
 2 files changed, 91 insertions(+), 23 deletions(-)

diff --git a/src/06-mini-project/daemon/oled/oled.c b/src/06-mini-project/daemon/oled/oled.c
index e3f4d7a..f4be528 100644
--- a/src/06-mini-project/daemon/oled/oled.c
+++ b/src/06-mini-project/daemon/oled/oled.c
@@ -1,28 +1,84 @@
-//
-// Created by fastium on 6/5/26.
-//
-
 #include "oled.h"
 
 #include "ssd1306.h"
 
-int display()
-{
-    ssd1306_init();
+#include "oled.h"
+#include "ssd1306.h"
+#include <pthread.h>
+#include <stdio.h>
+#include <unistd.h>
 
-    ssd1306_set_position (0,0);
+/* Internal reference to the registered callbacks */
+static struct oled_callbacks_t* oled_cbs = NULL;
+
+/* Thread handle for the background update loop */
+static pthread_t oled_thread;
+
+/**
+ * display() - Formats and sends dynamic data to the OLED screen.
+ *
+ * This function uses snprintf to convert numerical values into strings
+ * before sending them to the SSD1306 controller.
+ */
+static void display(int mode, float temp, uint32_t period_ms) {
+    char buffer[20];
+
+    /* Static header rows */
+    ssd1306_set_position(0, 0);
     ssd1306_puts("CSEL1a - SP.07");
-    ssd1306_set_position (0,1);
-    ssd1306_puts("  Demo - SW");
-    ssd1306_set_position (0,2);
+    ssd1306_set_position(0, 1);
+    ssd1306_puts("  WATCHDOG CPU ");
+    ssd1306_set_position(0, 2);
     ssd1306_puts("--------------");
 
-    ssd1306_set_position (0,3);
-    ssd1306_puts("Temp: 35'C");
-    ssd1306_set_position (0,4);
-    ssd1306_puts("Freq: 1Hz");
-    ssd1306_set_position (0,5);
-    ssd1306_puts("Duty: 50%");
+    /* Mode display: switches between AUTO and MANU strings */
+    ssd1306_set_position(0, 3);
+    snprintf(buffer, sizeof(buffer), "Mode: %s", mode ? "AUTO" : "MANU");
+    ssd1306_puts(buffer);
 
-    return 0;
+    /* Temperature display: formatted with one decimal precision */
+    ssd1306_set_position(0, 4);
+    snprintf(buffer, sizeof(buffer), "Temp: %.1f'C", temp);
+    ssd1306_puts(buffer);
+
+    /* Period/Frequency display: shows the value in milliseconds */
+    ssd1306_set_position(0, 5);
+    float freq = 1.0f / (period_ms / 1000.0f);
+    snprintf(buffer, sizeof(buffer), "Freq: %.1fHz", freq);
+    ssd1306_puts(buffer);
+}
+
+/**
+ * update_oled_thread() - Continuous loop for screen refreshing.
+ *
+ * Runs at a 250ms interval to provide a responsive display without
+ * overloading the I2C bus.
+ */
+static void *update_oled_thread(void* arg) {
+    while (1) {
+        if (oled_cbs != NULL) {
+            /* Fetch fresh data using callbacks and update screen */
+            display(
+                oled_cbs->get_mode(),
+                oled_cbs->get_temperature(),
+                oled_cbs->get_period()
+            );
+        }
+        /* Sleep to control refresh rate and save CPU cycles */
+        usleep(250000);
+    }
+    return NULL;
+}
+
+void init_oled(struct oled_callbacks_t* cbs) {
+    if (cbs != NULL) {
+        oled_cbs = cbs;
+    }
+
+    /* Initialize the hardware driver */
+    ssd1306_init();
+
+    /* Start the background thread for automatic updates */
+    pthread_create(&oled_thread, NULL, update_oled_thread, NULL);
+    pthread_detach(oled_thread);
 }
diff --git a/src/06-mini-project/daemon/oled/oled.h b/src/06-mini-project/daemon/oled/oled.h
index 238fb81..dc1962b 100644
--- a/src/06-mini-project/daemon/oled/oled.h
+++ b/src/06-mini-project/daemon/oled/oled.h
@@ -1,8 +1,20 @@
-//
-// Created by fastium on 6/5/26.
-//
-
 #ifndef MSE_MA_CSEL_OLED_H
 #define MSE_MA_CSEL_OLED_H
 
-#endif //MSE_MA_CSEL_OLED_H
\ No newline at end of file
+
+#include <stdint.h>
+
+/* Callback structure to decouple the OLED module from the application logic */
+struct oled_callbacks_t {
+    float (*get_temperature)(void);
+    int (*get_mode)(void);
+    uint32_t (*get_period)(void);
+};
+
+/*
+ * Initialize the SSD1306 display and start the background refresh thread.
+ * The cbs parameter provides the functions needed to fetch real-time data.
+ */
+void init_oled(struct oled_callbacks_t* cbs);
+
+#endif //MSE_MA_CSEL_OLED_H