diff --git a/Src/dshot.c b/Src/dshot.c
index a55ffefe..e3e9dee9 100644
--- a/Src/dshot.c
+++ b/Src/dshot.c
@@ -12,43 +12,47 @@
 #include "sounds.h"
 #include "targets.h"
 
-int dpulse[16] = { 0 };
+static uint8_t dpulse[16];
 
-const char gcr_encode_table[16] = {
+static const uint8_t gcr_encode_table[16] = {
     0b11001, 0b11011, 0b10010, 0b10011, 0b11101, 0b10101, 0b10110, 0b10111,
     0b11010, 0b01001, 0b01010, 0b01011, 0b11110, 0b01101, 0b01110, 0b01111
 };
 
-char EDT_ARM_ENABLE = 0;
-char EDT_ARMED = 0;
-int shift_amount = 0;
-uint32_t gcrnumber;
+char EDT_ARM_ENABLE;
+char EDT_ARMED;
+static int shift_amount;
+static uint32_t gcrnumber;
 extern int zero_crosses;
 extern char send_telemetry;
 extern uint8_t max_duty_cycle_change;
-int dshot_full_number;
+static uint32_t dshot_full_number;
 extern char play_tone_flag;
-uint8_t command_count = 0;
-uint8_t last_command = 0;
-uint8_t high_pin_count = 0;
-uint32_t gcr[37] = { 0 };
-uint16_t dshot_frametime;
-uint16_t dshot_goodcounts;
-uint16_t dshot_badcounts;
-char dshot_extended_telemetry = 0;
-uint16_t send_extended_dshot = 0;
-uint16_t processtime = 0;
-uint16_t halfpulsetime = 0;
+static uint8_t command_count;
+static uint8_t last_command;
+static uint8_t high_pin_count;
+uint32_t gcr[37];
+static uint16_t dshot_frametime;
+static uint16_t dshot_goodcounts;
+static uint16_t dshot_badcounts;
+char dshot_extended_telemetry;
+uint16_t send_extended_dshot;
+static uint16_t halfpulsetime;
 
 void computeDshotDMA()
 {
-    int j = 0;
     dshot_frametime = dma_buffer[31] - dma_buffer[0];
     halfpulsetime = dshot_frametime >> 5;
     if ((dshot_frametime > dshot_frametime_low) && (dshot_frametime < dshot_frametime_high)) {
-			signaltimeout = 0;
+        signaltimeout = 0;
         for (int i = 0; i < 16; i++) {
-            dpulse[i] = ((dma_buffer[j + (i << 1) + 1] - dma_buffer[j + (i << 1)]) > (halfpulsetime));
+            const uint16_t pwidth = dma_buffer[(i << 1) + 1] - dma_buffer[(i << 1)];
+            if (pwidth < (halfpulsetime>>1) || pwidth > (halfpulsetime<<1)) {
+                // pulse width way off, bad frame
+                dshot_badcounts++;
+                return;
+            }
+            dpulse[i] = (pwidth > halfpulsetime);
         }
         uint8_t calcCRC = ((dpulse[0] ^ dpulse[4] ^ dpulse[8]) << 3 | (dpulse[1] ^ dpulse[5] ^ dpulse[9]) << 2 | (dpulse[2] ^ dpulse[6] ^ dpulse[10]) << 1 | (dpulse[3] ^ dpulse[7] ^ dpulse[11]));
         uint8_t checkCRC = (dpulse[12] << 3 | dpulse[13] << 2 | dpulse[14] << 1 | dpulse[15]);