init PE4302 attenuation cache as impossible value

si4432.c

@@ -125,7 +125,7 @@ static void shiftOutBuf(uint8_t *buf, uint16_t size) {
 }
 #endif
 
-const uint16_t SI_nSEL[MAX_SI4432] = { GPIO_RX_SEL, GPIO_LO_SEL, 0}; // #3 is dummy!!!!!!
+const uint16_t SI_nSEL[MAX_SI4432+1] = { GPIO_RX_SEL, GPIO_LO_SEL, 0}; // #3 is dummy!!!!!!
 
 volatile int SI4432_Sel = 0;         // currently selected SI4432
 // volatile int SI4432_guard = 0;
@@ -659,11 +659,11 @@ void PE4302_shiftOut(uint8_t val)
 }
 #endif
 
-static unsigned char old_attenuation = 0;
+static unsigned char old_attenuation = 255;
 bool PE4302_Write_Byte(unsigned char DATA )
 {
-//  if (old_attenuation == DATA)
-//    return false;
+  if (old_attenuation == DATA)
+    return false;
 //  chThdSleepMicroseconds(PE4302_DELAY);
   SPI2_CLK_LOW;
 //  chThdSleepMicroseconds(PE4302_DELAY);