Add backup checksum

main.c

@@ -172,9 +172,17 @@ static THD_FUNCTION(Thread1, arg)
         b.RBW = SI4432_rbw_selected+1;
 #endif
       b.mode = setting.mode;
+      b.checksum = 0;
+      uint8_t *c = (uint8_t *)&b;
+      int ci = USED_BACKUP_SIZE*4;
+      uint8_t checksum = 0x55;
+      while (ci--) {
+        checksum ^= *c++;
+      }
+      b.checksum = checksum;
       uint32_t *f = (uint32_t *)&b;
       uint32_t *t = &backup;
-      int i = USED_BACKUP_SIZE;
+      int i = USED_BACKUP_SIZE+1;
       while (i--)
         *t++ = *f++;
 
@@ -2928,9 +2936,16 @@ int main(void)
     backup_t b;
     uint32_t *f = &backup;
     uint32_t *t = (uint32_t *)&b;
-    int i = USED_BACKUP_SIZE;
+    int i = USED_BACKUP_SIZE+1;
     while (i--)
       *t++ = *f++;
+    uint8_t *c = (uint8_t *)&b;
+    int ci = USED_BACKUP_SIZE*3;
+    uint8_t checksum = 0x55;
+    while (ci--) {
+      checksum ^= *c++;
+    }
+    if (b.checksum == checksum) {
 #ifdef TINYSA4       // Set mode not working reliably
       set_mode(b.mode);
       switch (b.mode) {
@@ -2974,14 +2989,15 @@ int main(void)
         }
       }
     }
+  }
   set_refer_output(-1);
-//  ui_mode_menu();       // Show menu when autostarting mode
+  //  ui_mode_menu();       // Show menu when autostarting mode
 
   /*
    * Set LCD display brightness (use DAC2 for control)
    * Starting DAC1 driver, setting up the output pin as analog as suggested by the Reference Manual.
    */
-   #ifdef  __LCD_BRIGHTNESS__
+#ifdef  __LCD_BRIGHTNESS__
     lcd_setBrightness(config._brightness);
   #else
     DAC->DHR12R2 = config.dac_value; // Setup DAC: CH2 value

nanovna.h

@@ -1709,6 +1709,7 @@ typedef struct {
   uint8_t reflevel;
   uint8_t RBW;
   uint8_t mode;
+  uint8_t checksum;
 } backup_t;
 #pragma pack(pop)