diff --git a/src/cppmain.cc b/src/cppmain.cc
index 78e7e24..173e37f 100644
--- a/src/cppmain.cc
+++ b/src/cppmain.cc
@@ -10,14 +10,20 @@
 
 #define SAMPLE_FREQ 44200
 #define SAMPLE_MAX 4096
-#define DOUBLE_BUFFER_SIZE 16
-#define BUFFER_SIZE 8
+#define BUFFER_SIZE 16
+#define BLOCK_SIZE 8
 
 const double pi{ std::acos(-1) };
-static u32 double_buffer[DOUBLE_BUFFER_SIZE];
+
+// Buffer and block
+static u32 audio_buffer[BUFFER_SIZE];
+static u32* block = &audio_buffer[0];
+static volatile bool process_block{ false };
+
+// time
 static u64 time{ 0 };
-static volatile bool dma_to_dac_half_complete{ false };
-static volatile bool dma_to_dac_complete{ false };
+
+// misc
 static volatile int freq = 100;
 
 namespace Heck {
@@ -37,11 +43,6 @@ namespace Heck {
         CDC_Transmit_FS((uint8_t *)out.data(), out.size());
     }
 
-
-    // DAC
-    // ---
-
-
     // LED
     // ---
     void led_green_toggle()
@@ -59,7 +60,6 @@ namespace Heck {
         HAL_GPIO_WritePin(GPIOD, GPIO_PIN_12, GPIO_PIN_RESET);
     }
 
-
     // CALLBACKS
     void irq1_cb()
     {
@@ -93,46 +93,46 @@ namespace Heck {
         ret %= max;
         return ret;
     }
-    //
-    //    void buffer_init_noise()
-    //    {
-    //        log("buffer_init_noise()");
-    //        for (int i = 0; i < DOUBLE_BUFFER_SIZE; i++) {
-    //            u32 val = random(SAMPLE_MAX);
-    //            double_buffer[i] = val;
-    //            log(std::to_string(val));
-    //        }
-    //    }
-    //
-    //    void buffer_init_sin()
-    //    {
-    //        log("buffer_init_sin()");
-    //        for (int i = 0; i < DOUBLE_BUFFER_SIZE; i++) {
-    //            float p = float(i) / (float)DOUBLE_BUFFER_SIZE - 0.5;
-    //            u32 val = sin(p) * SAMPLE_MAX;
-    //            double_buffer[i] = val;
-    //            log(std::to_string(val));
-    //        }
-    //    }
-    //
-    //    void buffer_div(int div)
-    //    {
-    //        log("init_scale()");
-    //        for (int i = 0; i < DOUBLE_BUFFER_SIZE; i++) {
-    //            u32 val = double_buffer[i] / div;
-    //            double_buffer[i] = val;
-    //            log(std::to_string(val));
-    //        }
-    //    }
-    //
-    //    void buffer_randomize(int max)
-    //    {
-    //        log("buffer_randomize()");
-    //        u32 buf_index = random(DOUBLE_BUFFER_SIZE);
-    //        u32 buf_val = random(max);
-    //        double_buffer[buf_index] = buf_val;
-    //        log("i:" + std::to_string(buf_index) + " v:" + std::to_string(buf_val));
-    //    }
+
+    void buffer_init_noise()
+    {
+        log("buffer_init_noise()");
+        for (int i = 0; i < BUFFER_SIZE; i++) {
+            u32 val = random(SAMPLE_MAX);
+            audio_buffer[i] = val;
+            log(std::to_string(val));
+        }
+    }
+
+    void buffer_init_sin()
+    {
+        log("buffer_init_sin()");
+        for (int i = 0; i < BUFFER_SIZE; i++) {
+            float p = float(i) / (float)BUFFER_SIZE - 0.5;
+            u32 val = sin(p) * SAMPLE_MAX;
+            audio_buffer[i] = val;
+            log(std::to_string(val));
+        }
+    }
+
+    void buffer_div(int div)
+    {
+        log("init_scale()");
+        for (int i = 0; i < BUFFER_SIZE; i++) {
+            u32 val = audio_buffer[i] / div;
+            audio_buffer[i] = val;
+            log(std::to_string(val));
+        }
+    }
+
+    void buffer_randomize(int max)
+    {
+        log("buffer_randomize()");
+        u32 buf_index = random(BUFFER_SIZE);
+        u32 buf_val = random(max);
+        audio_buffer[buf_index] = buf_val;
+        log("i:" + std::to_string(buf_index) + " v:" + std::to_string(buf_val));
+    }
 
     std::string reg_to_string(uint32_t val)
     {
@@ -150,14 +150,14 @@ namespace Heck {
     }
 
 
-    void calculate_audio(u32 *buffer)
+    void calculate_audio()
     {
-        log("calculate_audio time: ");
+//        log("calculate_audio time: ");
         u64 t = time;
         u32 samps = hz_to_samps(freq);
 
-        for (int i = 0; i < BUFFER_SIZE; i++) {
-            buffer[i] = t % samps;
+        for (int i = 0; i < BLOCK_SIZE; i++) {
+            block[i] = t % samps;
             t++;
         }
     }
@@ -168,21 +168,15 @@ namespace Heck {
         log("Starting...");
 
         HAL_TIM_Base_Start_IT(&htim_blinky_led);
-        HAL_DAC_Start_DMA(&hdac1, DAC_CHANNEL_1, (u32 *)double_buffer, DOUBLE_BUFFER_SIZE, DAC_ALIGN_12B_R);
+        HAL_DAC_Start_DMA(&hdac1, DAC_CHANNEL_1, (u32 *)audio_buffer, BUFFER_SIZE, DAC_ALIGN_12B_R);
         HAL_TIM_Base_Start_IT(&htim_dac1);
 
         log("Entering MainLoop...");
         while (true) {
-            if (dma_to_dac_half_complete) {
-                calculate_audio(&double_buffer[0]);
-                time += BUFFER_SIZE;
-                dma_to_dac_half_complete = false;
-            }
-            if (dma_to_dac_complete) {
-
-                calculate_audio(&double_buffer[BUFFER_SIZE]);
-                time += BUFFER_SIZE;
-                dma_to_dac_complete = false;
+            if (process_block) {
+                calculate_audio();
+                time += BLOCK_SIZE;
+                process_block = false;
             }
         }
     }
@@ -232,13 +226,15 @@ extern "C" void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
 extern "C" void HAL_DAC_ConvHalfCpltCallbackCh1(DAC_HandleTypeDef *hdac)
 {
     Heck::log("HAL_DAC_ConvHalfCpltCallbackCh1");
-    dma_to_dac_half_complete = true;
+    block = &audio_buffer[0];
+    process_block = true;
 }
 
 extern "C" void HAL_DAC_ConvCpltCallbackCh1(DAC_HandleTypeDef *hdac)
 {
     Heck::log("HAL_DAC_ConvCpltCallbackCh1");
-    dma_to_dac_complete = true;
+    block = &audio_buffer[BUFFER_SIZE];
+    process_block = true;
 }