set address by GPIOs 11, 12, 13

rotator/rotator.ino

@@ -1,10 +1,10 @@
 #include <Wire.h>
 
-#define PIN_HEADING_WHITE PD3
-#define PIN_HEADING_RED PD6
+#define PIN_HEADING_WHITE 3
+#define PIN_HEADING_RED 5
 
-#define PIN_ALTITUDE_WHITE PD2
-#define PIN_ALTITUDE_RED PD5
+#define PIN_ALTITUDE_WHITE 2
+#define PIN_ALTITUDE_RED 4
 
 #define VALUE_BUFFER 30
 
@@ -16,6 +16,9 @@
 #define HEADING_HIGH_BIT 2
 #define ALTITUDE_TRIGGER_BIT 4
 #define ALTITUDE_HIGH_BIT 8
+#define PIN_ADDRESS_1 11
+#define PIN_ADDRESS_2 12
+#define PIN_ADDRESS_3 13
 
 int lastClk = HIGH;
 
@@ -92,18 +95,30 @@ void i2cRequest() {
   }
 }
 
+uint8_t address = 0;
 void setup() {
   Serial.begin(115200);
 
+  // setup rotator GPIOs
   pinMode(PIN_HEADING_WHITE, INPUT_PULLUP);
   pinMode(PIN_HEADING_RED, INPUT_PULLUP);
   pinMode(PIN_ALTITUDE_WHITE, INPUT_PULLUP);
   pinMode(PIN_ALTITUDE_RED, INPUT_PULLUP);
 
+  // setup address selector GPIOs
+  pinMode(PIN_ADDRESS_1, INPUT_PULLUP);
+  pinMode(PIN_ADDRESS_2, INPUT_PULLUP);
+  pinMode(PIN_ADDRESS_3, INPUT_PULLUP);
+
+  // calculate address by LOW GPIOs
+  address = digitalRead(PIN_ADDRESS_1) == LOW;
+  address |= (digitalRead(PIN_ADDRESS_2) == LOW) << 1;
+  address |= (digitalRead(PIN_ADDRESS_3) == LOW) << 2;
+
   attachInterrupt(digitalPinToInterrupt(PIN_ALTITUDE_WHITE), altitudeFalling, FALLING);
   attachInterrupt(digitalPinToInterrupt(PIN_HEADING_WHITE), headingFalling, FALLING);
 
-  Wire.begin(0x01);
+  Wire.begin(address);
   Wire.onRequest(i2cRequest);
 }