diff --git a/main.cpp b/main.cpp
index c9a372e..05ae250 100644
--- a/main.cpp
+++ b/main.cpp
@@ -24,14 +24,17 @@ namespace net = std::experimental::net;
 void fft_mag(std::complex<float>* in, float* out, size_t len);
 
 
+static const size_t block_len = 16384;
+static const int wf_width = 1000;
+static const int wf_height = 2000;
+
+
 static std::atomic<bool> terminate_dsp;
 
-struct bladerf* bladerf_dev;
+static struct bladerf* bladerf_dev;
 
-static std::mutex waterfall_data_mutex;
-static int waterfall_width = 1000;
-static int waterfall_height = 2000;
-static unsigned int waterfall_data[1000*2000];
+static std::mutex wf_data_mutex;
+static unsigned int wf_data[wf_width*wf_height];
 
 static std::atomic<float> freq_setpoint;
 static std::atomic<float> freq_peak;
@@ -41,35 +44,35 @@ static std::atomic<float> tec_current;
 
 static std::atomic<int> fps;
 
-static void dsp_thread() {
+static void dsp_thread()
+{
     using namespace std::literals::chrono_literals;
 
     net::io_context io_context;
     net::ip::tcp::socket tec_socket(io_context);
     tec_socket.connect(net::ip::tcp::endpoint(net::ip::make_address("192.168.1.27"), 23));
 
-    size_t len = 16384;
-    std::vector<std::complex<int16_t>> frames(len);
-    std::vector<std::complex<float>> frames_f(len);
-    std::vector<float> frames_mag(len);
+    std::vector<std::complex<int16_t>> frames(block_len);
+    std::vector<std::complex<float>> frames_f(block_len);
+    std::vector<float> frames_mag(block_len);
 
     int iterations = 0;
     auto last_second = std::chrono::steady_clock::now();
     auto last_tec = std::chrono::steady_clock::now();
     while(!terminate_dsp) {
         int status;
-        if((status = bladerf_sync_rx(bladerf_dev, frames.data(), len, NULL, 0)) != 0) {
+        if((status = bladerf_sync_rx(bladerf_dev, frames.data(), block_len, NULL, 0)) != 0) {
             std::cerr << "failed to receive samples from bladeRF: " << bladerf_strerror(status) << std::endl;
             break;
         }
 
-        fft_mag(frames_f.data(), frames_mag.data(), len);
+        fft_mag(frames_f.data(), frames_mag.data(), block_len);
 
         // stabilize laser
         bool tick = false;
         if((std::chrono::steady_clock::now() - last_tec) >= 100ms) {
             float freq_peak_local;
-            freq_peak_local = 40.0f*float(distance(frames_mag.begin(), max_element(frames_mag.begin(), frames_mag.end())))/float(len);
+            freq_peak_local = 40.0f*float(distance(frames_mag.begin(), max_element(frames_mag.begin(), frames_mag.end())))/float(block_len);
             freq_peak = freq_peak_local;
             float freq_error = freq_peak_local - freq_setpoint;
             float tec_current_local = std::max(tec_bias+tec_p*freq_error, 0.0f);
@@ -91,16 +94,16 @@ static void dsp_thread() {
 
         // update waterfall
         {
-            std::lock_guard<std::mutex> guard(waterfall_data_mutex);
-            std::memmove(&waterfall_data[waterfall_width], &waterfall_data[0], sizeof(int)*waterfall_width*(waterfall_height - 1));
-            for(int i=0;i<waterfall_width;i++) {
-                int j = i*len/waterfall_width;
-                waterfall_data[i] = 0xff000000 | 0x010101*std::min(int(frames_mag[j]/900.0f), 255);
+            std::lock_guard<std::mutex> guard(wf_data_mutex);
+            std::memmove(&wf_data[wf_width], &wf_data[0], sizeof(int)*wf_width*(wf_height - 1));
+            for(int i=0;i<wf_width;i++) {
+                int j = i*block_len/wf_width;
+                wf_data[i] = 0xff000000 | 0x010101*std::min(int(frames_mag[j]/900.0f), 255);
             }
-            waterfall_data[int(freq_setpoint*waterfall_width)/40] = 0xff0000ff;
+            wf_data[int(freq_setpoint*wf_width)/40] = 0xff0000ff;
             if(tick)
                 for(int i=0;i<100;i++)
-                    waterfall_data[i] = 0xffff0000;
+                    wf_data[i] = 0xffff0000;
         }
 
         // FPS counter
@@ -223,8 +226,8 @@ int main(int argc, char* argv[])
         glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
         #endif
         if(update) {
-            std::lock_guard<std::mutex> guard(waterfall_data_mutex);
-            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, waterfall_width, waterfall_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, waterfall_data);
+            std::lock_guard<std::mutex> guard(wf_data_mutex);
+            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, wf_width, wf_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, wf_data);
         }
 
         ImGui_ImplOpenGL3_NewFrame();
@@ -253,7 +256,7 @@ int main(int argc, char* argv[])
             exit = true;
         ImGui::Text("FPS: %d", (int)fps);
         ImGui::TableNextColumn();
-        ImGui::Image((void*)(intptr_t)waterfall, ImVec2(waterfall_width, waterfall_height));
+        ImGui::Image((void*)(intptr_t)waterfall, ImVec2(wf_width, wf_height));
         ImGui::EndTable();
 
         ImGui::End();