diff --git a/src/gps.c b/src/gps.c
--- a/src/gps.c
+++ b/src/gps.c
@@ -3,6 +3,7 @@
 #include "stm32f0xx_hal.h"
 
 #include "config.h"
+#include "gpio.h"
 #include "usart.h"
 #include "gps.h"
 
@@ -25,13 +26,19 @@ char tramsmissionType[7];
 void gps_poweron(void)
 {
     // NOTE: pchannel
-    //gpio_clear(GPS_ONOFF);
+    HAL_GPIO_WritePin(GPS_NOTEN, 0);
+    uart_init();
+
+    // Begin DMA reception
+    HAL_UART_Receive_DMA(uart_gethandle(), nmeaBuffer, NMEABUFFER_SIZE);
+
 }
 
 void gps_poweroff(void)
 {
     // NOTE: pchannel
-    //gpio_set(GPS_ONOFF);
+    uart_deinit();
+    HAL_GPIO_WritePin(GPS_NOTEN, 1);
 }
 
 char timestamp[12];	//hhmmss.ss
@@ -86,6 +93,18 @@ char* get_hdop()
 	return hdop;
 }
 
+uint16_t get_hdop_int_tenths(void)
+{
+    // If only one digit before decimal
+    if(hdop[1] == '.')
+    {
+        return (hdop[0]-0x30)*10 + (hdop[2]-0x30);
+    }
+
+    // Return normal hdop
+    return (hdop[0]-0x30)*100 + (hdop[1]-0x30)*10 + (hdop[2]-0x30);
+}
+
 char altitude[10];	//xxxxxx.x
 char* get_gpsaltitude()
 {
@@ -170,10 +189,8 @@ enum decodeState {
 void gps_init() 
 {
     // Initialize serial port
-    uart_init();
+   // done in poweron uart_init();
 
-    // Begin DMA reception
-    HAL_UART_Receive_DMA(uart_gethandle(), nmeaBuffer, NMEABUFFER_SIZE);
 
     timestamp[0] = 0x00;
     latitude[0] = 0x00;
@@ -184,9 +201,6 @@ void gps_init()
     course[0] = 0x00;
     dayofmonth[0] = 0x00;
 
-    gps_poweron();
-    HAL_Delay(100); // Make sure GPS is awake and alive
-
 //    // Disable GLONASS mode
 //    uint8_t disable_glonass[20] = {0xB5, 0x62, 0x06, 0x3E, 0x0C, 0x00, 0x00, 0x00, 0x20, 0x01, 0x06, 0x08, 0x0E, 0x00, 0x00, 0x00, 0x01, 0x01, 0x8F, 0xB2};
 //
@@ -228,8 +242,69 @@ static void setParserState(uint8_t state
 }
 
 
+static uint8_t gps_acquiring = 0;
+static uint32_t gps_lastfix_time = 0;
 
-//// MKa GPS transmission parser START
+
+
+void gps_process(void)
+{
+    // If we're trying to acquire a GPS fix
+    if(gps_acquiring)
+    {
+        // Process incoming bytes
+        parse_gps_transmission();
+
+        // If fix acquired
+        uint16_t hdop_int = get_hdop_int_tenths();
+        if(hdop_int < 50 && hdop_int > 0)
+        {
+            // Set RTC to GPS time
+
+            // Record time of fix (TODO: don't use ticks if sleeping... use RTC time)
+            gps_lastfix_time = HAL_GetTick();
+
+            // Turn off GPS module
+            gps_poweroff();
+
+            // Invalidate HDOP
+            hdop[0] = '9';
+
+            // Go to idle state
+            gps_acquiring = 0;
+        }
+        else
+        {
+            // if too much time has elapsed, set an error flag and go idle
+            //gps_acquiring = 0;
+        }
+    }
+}
+
+void gps_acquirefix(void)
+{
+    gps_poweron();
+
+    // Wait for fix
+    gps_acquiring = 1;
+}
+
+
+
+uint8_t gps_getstate(void)
+{
+    if(gps_acquiring)
+        return GPS_STATE_ACQUIRING;
+    else if(gps_lastfix_time == 0)
+        return GPS_STATE_NOFIX;
+    else if(HAL_GetTick() - gps_lastfix_time < GPS_STALEFIX_MS)
+        return GPS_STATE_FRESHFIX;
+    else
+        return GPS_STATE_STALEFIX;
+
+}
+
+// MKa GPS transmission parser START
 void parse_gps_transmission(void)
 {
     uint16_t nmeaBufferDataPosition = NMEABUFFER_SIZE - uart_get_rxdma_handle()->Instance->CNDTR;