diff --git a/src/main.cpp b/src/main.cpp
index 37298fa..c2c2ab7 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -21,12 +21,13 @@
 Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
 
 Servo servo;
-int servoPin = 13;
+int servoPin = 16;
 
 SoftwareSerial altserial(14, 12); // rx, tx
 Adafruit_GPS GPS(&altserial);
 
 uint32_t tstamp = millis();
+float az = 0.0;
 
 typedef struct {
   time_t epoch;
@@ -79,7 +80,7 @@ void init_servo() {
 // ///////////////////////////////////////////////////////////////////////////////////////
 void setup() {
   Serial.begin(115200);
-//  init_servo();
+  init_servo();
   init_display();
   init_gps();
   wmm_init();
@@ -165,19 +166,32 @@ void debug_solar() {
   // Serial.print("Antenna status: "); Serial.println((int)GPS.antenna);
 }
 
-// void servo_sweep() {
-//   int pos;
+// value 80 mirror is pointing up
+// 180 is pointing forward at 90 degrees
+void hg_set_zenith(float z) {
+  Serial.print("moving to zenith ->  ");
+  Serial.print( z );
+  Serial.println();
+  int a = (int)ceilf(180.0 - z);
+  servo.write( a );
+  delay(20);
+}
 
-// 	for (pos = 0; pos <= 180; pos += 1) { // goes from 0 degrees to 180 degrees
-// 		// in steps of 1 degree
-// 		servo.write(pos);    // tell servo to go to position in variable 'pos'
-// 		delay(15);             // waits 15ms for the servo to reach the position
-// 	}
-// 	for (pos = 180; pos >= 0; pos -= 1) { // goes from 180 degrees to 0 degrees
-// 		servo.write(pos);    // tell servo to go to position in variable 'pos'
-// 		delay(15);             // waits 15ms for the servo to reach the position
-// 	}
-// }
+/*
+void servo_sweep() {
+  int pos;
+
+	for (pos = 0; pos <= 180; pos += 1) { // goes from 0 degrees to 180 degrees
+		// in steps of 1 degree
+		servo.write(pos);    // tell servo to go to position in variable 'pos'
+		delay(10);             // waits 15ms for the servo to reach the position
+	}
+	for (pos = 180; pos >= 0; pos -= 1) { // goes from 180 degrees to 0 degrees
+		servo.write(pos);    // tell servo to go to position in variable 'pos'
+		delay(10);             // waits 15ms for the servo to reach the position
+	}
+}
+*/
 
 float compute_magnetic_declination() {
   float wmmtime = wmm_get_date(GPS.year, GPS.month, GPS.day);
@@ -226,7 +240,7 @@ void gps_pump() {
 
 void loop() {
   gps_pump();
-  
+
   // // approximately every 2 seconds or so, print out the current stats
   if (millis() - tstamp > 2000) {
     tstamp = millis(); // reset the timer
@@ -241,10 +255,17 @@ void loop() {
   //     // servo.write( ceil(sun.elevation) );
   //     // delay(20);
 
+      // move mirror to zenith position
+      //hg_set_zenith(sun.zenith);
+      hg_set_zenith(az);
+      az += 1.0;
+      if(az > 180) { az = .0; }
+
       // debug_solar();
       ui_sunpos();
     } else {
       ui_nogpsfix();
     }
   }
+
 } // loop()