diff --git a/firmware/application/apps/ui_dfu_menu.cpp b/firmware/application/apps/ui_dfu_menu.cpp
index 24ee12593..e7fa7bb1c 100644
--- a/firmware/application/apps/ui_dfu_menu.cpp
+++ b/firmware/application/apps/ui_dfu_menu.cpp
@@ -59,7 +59,7 @@ void DfuMenu::paint(Painter& painter) {
     text_info_line_7.set(to_string_dec_uint(shared_memory.m4_stack_usage, 6));
     text_info_line_8.set(to_string_dec_uint(shared_memory.m4_performance_counter, 6));
     text_info_line_9.set(to_string_dec_uint(shared_memory.m4_buffer_missed, 6));
-    text_info_line_10.set(to_string_dec_uint(chTimeNow() / 1000, 6));
+    text_info_line_10.set(to_string_dec_uint(chTimeNow() / CH_FREQUENCY, 6));
 
     constexpr auto margin = 5;
 
diff --git a/firmware/application/apps/ui_settings.cpp b/firmware/application/apps/ui_settings.cpp
index 9bc19fcf1..795dd4b0e 100644
--- a/firmware/application/apps/ui_settings.cpp
+++ b/firmware/application/apps/ui_settings.cpp
@@ -1012,10 +1012,17 @@ void SetTouchscreenThresholdView::focus() {
 
 void SetTouchscreenThresholdView::on_frame_sync() {
     if (!in_auto_detect) return;
+
     uint32_t time_now = chTimeNow();
     int32_t time_diff = time_now - time_start_auto_detect;
-    text_wait_timer.set("ETA " + to_string_dec_uint((10 - time_diff / 1000) <= 0 ? 0 : 10 - time_diff / 1000) + "s");
-    if (time_diff >= 10001 && !auto_detect_succeed_consumed) {  // 10s
+
+    // Calculate elapsed seconds using CH_FREQUENCY
+    uint32_t elapsed_seconds = time_diff / CH_FREQUENCY;
+    int32_t remaining_seconds = 10 - (int32_t)elapsed_seconds;
+    if (remaining_seconds < 0) remaining_seconds = 0;
+
+    text_wait_timer.set("ETA " + to_string_dec_uint(remaining_seconds) + "s");
+    if (elapsed_seconds >= 10 && !auto_detect_succeed_consumed) {  // 10s
         in_auto_detect = false;
         text_wait_timer.hidden(true);
         text_hint.set("OK, press save and reboot");
diff --git a/firmware/application/clock_manager.cpp b/firmware/application/clock_manager.cpp
index b93777b8c..7bf280bac 100644
--- a/firmware/application/clock_manager.cpp
+++ b/firmware/application/clock_manager.cpp
@@ -428,7 +428,7 @@ void ClockManager::portapack_tcxo_enable() {
 
     /* Delay >10ms at 96MHz clock speed for reference oscillator to start. */
     /* Delay an additional 1ms (arbitrary) for the clock generator to detect a signal. */
-    volatile uint32_t delay = 240000 + 24000;
+    volatile uint32_t delay = 2400000 + 24000;
     while (delay--);
 }
 
@@ -668,37 +668,37 @@ ClockManager::ReferenceSource ClockManager::detect_reference_source() {
 }
 
 ClockManager::Reference ClockManager::choose_reference() {
-#ifdef PRALINE
-    const auto detected_reference = detect_reference_source();
-
-    if ((detected_reference == ReferenceSource::External) ||
-        (detected_reference == ReferenceSource::PortaPack)) {
-        const auto frequency = measure_gp_clkin_frequency();
-        if ((frequency >= 9850000) && (frequency <= 10150000)) {
-            return {detected_reference, 10000000};
-        }
-    }
-#else
+#ifndef PRALINE
     if (hackrf_r9) {
         gpio_control::r9_clkin_en.setActive();
-        volatile uint32_t delay = 240000 + 24000;
+        // Allow extra time for slower TCXOs on clone boards to stabilize before measurement
+        volatile uint32_t delay = 240000 + 240000;
         while (delay--);
     }
+#endif
+
+    // Determine reference source (respects user config and Si5351 loss-of-signal)
     const auto detected_reference = detect_reference_source();
 
+    // If an external or PortaPack source is detected, verify its actual frequency
     if ((detected_reference == ReferenceSource::External) ||
         (detected_reference == ReferenceSource::PortaPack)) {
         const auto frequency = measure_gp_clkin_frequency();
+
+        // Check if the measured frequency is within the valid 10 MHz range
         if ((frequency >= 9850000) && (frequency <= 10150000)) {
             return {detected_reference, 10000000};
         }
     }
 
+#ifndef PRALINE
     if (hackrf_r9) {
+        // Disable r9 clock input if the 10 MHz validation failed
         gpio_control::r9_clkin_en.setInactive();
     }
 #endif
 
+    // Fallback: Disable PortaPack TCXO and default to the HackRF 25 MHz crystal
     portapack_tcxo_disable();
     return {ReferenceSource::Xtal, 25000000};
 }
diff --git a/firmware/application/ui_navigation.cpp b/firmware/application/ui_navigation.cpp
index a259f3315..e9bb43786 100644
--- a/firmware/application/ui_navigation.cpp
+++ b/firmware/application/ui_navigation.cpp
@@ -1130,13 +1130,18 @@ void SystemView::toggle_overlay() {
 }
 
 void SystemView::paint_overlay() {
-    static bool last_paint_state = false;
+    // Static variable to store the timestamp of the last update
+    static systime_t last_update_time = 0;
+
     if (overlay_active) {
-        // paint background only every other second
-        if ((((chTimeNow() >> 10) & 0x01) == 0x01) == last_paint_state)
+        // Update exactly once per second (CH_FREQUENCY equals 1 second of ticks)
+        // This replaces the old hardcoded bit-shift logic for better portability
+        if ((chTimeNow() - last_update_time) < CH_FREQUENCY)
             return;
 
-        last_paint_state = !last_paint_state;
+        // One second has passed, save the new timestamp
+        last_update_time = chTimeNow();
+
         if (overlay_active == 1 && overlay)
             overlay->set_dirty();
         else if (overlay_active == 2 && overlay2)
diff --git a/firmware/application/usb_serial_shell.cpp b/firmware/application/usb_serial_shell.cpp
index 9e226d973..21f5e8476 100644
--- a/firmware/application/usb_serial_shell.cpp
+++ b/firmware/application/usb_serial_shell.cpp
@@ -1180,7 +1180,7 @@ static void cmd_sysinfo(BaseSequentialStream* chp, int argc, char* argv[]) {
         "M4 stack: " + to_string_dec_uint(shared_memory.m4_stack_usage) + "\r\n" +
         "M0 cpu%: " + to_string_dec_uint(shared_memory.m4_performance_counter) + "\r\n" +
         "M4 miss: " + to_string_dec_uint(shared_memory.m4_buffer_missed) + "\r\n" +
-        "uptime: " + to_string_dec_uint(chTimeNow() / 1000) + "\r\n";
+        "uptime: " + to_string_dec_uint(chTimeNow() / CH_FREQUENCY) + "\r\n";
 
     fillOBuffer(&((SerialUSBDriver*)chp)->oqueue, (const uint8_t*)info.c_str(), info.length());
     return;
diff --git a/firmware/baseband/debug.cpp b/firmware/baseband/debug.cpp
index 156a5de46..8e834d53c 100644
--- a/firmware/baseband/debug.cpp
+++ b/firmware/baseband/debug.cpp
@@ -125,15 +125,18 @@ void update_performance_counters() {
     if (performance_counter_active == 0x00)
         return;
 
-    static bool last_paint_state = false;
-    if ((((chTimeNow() >> 10) & 0x01) == 0x01) == last_paint_state)
+    static systime_t last_update_time = 0;
+
+    // The MS2ST(1000) guarantees that this is exactly 1 second, regardless of the system clock setting.
+    if ((chTimeNow() - last_update_time) < MS2ST(1000))
         return;
 
     // Idle thread state is sometimes unuseable
     if (chThdGetTicks(chSysGetIdleThread()) > 0x10000000)
         return;
 
-    last_paint_state = !last_paint_state;
+    // Update the last update time
+    last_update_time = chTimeNow();
 
     if (performance_counter_active == 0x01) {
         auto utilisation = get_cpu_utilisation_in_percent();
diff --git a/firmware/common/i2cdevmanager.cpp b/firmware/common/i2cdevmanager.cpp
index 9e39a0aa1..5111ae87b 100644
--- a/firmware/common/i2cdevmanager.cpp
+++ b/firmware/common/i2cdevmanager.cpp
@@ -318,29 +318,33 @@ void I2CDevManager::create_thread() {
 msg_t I2CDevManager::timer_fn(void* arg) {
     (void)arg;
     uint16_t curr_timer = 0;  // seconds since thread start
+
     while (1) {
         systime_t start_time = chTimeNow();
         bool changed = false;
-        // check if i2c scan needed
+
+        // Check if i2c scan is needed
         if (force_scan || (scan_interval != 0 && curr_timer % scan_interval == 0)) {
             changed = changed | scan();
             force_scan = false;
         }
+
+        // Update connected devices based on their own intervals
         for (size_t i = 0; i < devlist.size(); i++) {
             if (devlist[i].addr != 0 && devlist[i].dev && devlist[i].dev->query_interval != 0) {
-                if ((curr_timer % devlist[i].dev->query_interval) == 0) {  // only if it is device's interval
-                    devlist[i].dev->update();                              // updates it's data, and broadcasts it. if there is any error it will handle in it, and later we can remove it
+                if ((curr_timer % devlist[i].dev->query_interval) == 0) {
+                    devlist[i].dev->update();
                 }
             }
         }
 
-        // remove all unneeded items
+        // Remove all unneeded items (dead devices or devices throwing too many errors)
         chMtxLock(&mutex_list);
         size_t cnt = devlist.size();
         devlist.erase(std::remove_if(devlist.begin(), devlist.end(), [](const I2DevListElement& x) {
                           if (x.addr == 0) return true;
-                          if (x.dev && x.dev->need_del == true) return true;  // self destruct on too many errors
-                          return false;                                       // won't remove the unidentified ones, so we can list them, and not trying all the time with them
+                          if (x.dev && x.dev->need_del == true) return true;
+                          return false;
                       }),
                       devlist.end());
         chMtxUnlock();
@@ -350,11 +354,24 @@ msg_t I2CDevManager::timer_fn(void* arg) {
             I2CDevListChangedMessage msg{};
             EventDispatcher::send_message(msg);
         }
-        systime_t end_time = chTimeNow();
-        systime_t delta = (end_time > start_time) ? end_time - start_time : 100;  // wont calculate overflow, just guess.
-        if (delta > 950) delta = 950;                                             // ensure minimum 50 milli sleep
 
-        chThdSleepMilliseconds(1000 - delta);  // 1sec timer
+        systime_t end_time = chTimeNow();
+
+        // 1. Calculate elapsed ticks safely handling overflow
+        uint32_t delta_ticks = end_time - start_time;
+
+        // 2. Keep EVERYTHING in ticks (No MS conversion!) to prevent truncation drift
+        if (delta_ticks < CH_FREQUENCY) {
+            // Calculate exactly how many ticks are missing to complete 1 full second
+            uint32_t sleep_ticks = CH_FREQUENCY - delta_ticks;
+
+            // Sleep using native ticks instead of milliseconds
+            chThdSleep(sleep_ticks);
+        } else {
+            // Safety fallback: if processing took longer than 1 second, sleep 50ms to yield CPU
+            chThdSleepMilliseconds(50);
+        }
+
         ++curr_timer;
     }
     return 0;
diff --git a/firmware/common/jtag.hpp b/firmware/common/jtag.hpp
index 3ef42627c..4a2a554a0 100644
--- a/firmware/common/jtag.hpp
+++ b/firmware/common/jtag.hpp
@@ -59,8 +59,10 @@ class JTAG {
 
     void runtest_ms(const size_t count) {
         auto starttime = chTimeNow();
+        // We convert the count in milliseconds to system ticks:
+        auto duration_ticks = MS2ST(count) + 1;
 
-        while ((chTimeNow() - starttime) < (count + 1))
+        while ((chTimeNow() - starttime) < duration_ticks)
             target.clock(0, 0);
     }