diff --git a/ports/gprs_a9/modgps.c b/ports/gprs_a9/modgps.c
index bca68a3598875..c1c3862efffcd 100644
--- a/ports/gprs_a9/modgps.c
+++ b/ports/gprs_a9/modgps.c
@@ -47,9 +47,11 @@
 #include "py/mperrno.h"
 
 STATIC mp_obj_t modgps_off(void);
+mp_obj_t gps_callback = mp_const_none;
 
 void modgps_init0(void) {
     modgps_off();
+    gps_callback = mp_const_none;
 }
 
 // ------
@@ -60,37 +62,74 @@ GPS_Info_t* gpsInfo = NULL;
 
 void modgps_notify_gps_update(API_Event_t* event) {
     GPS_Update(event->pParam1,event->param1);
+
+    if (gps_callback && gps_callback != mp_const_none) {
+        mp_sched_schedule(gps_callback, MP_OBJ_NEW_SMALL_INT(0));
+    }
+}
+
+STATIC mp_obj_t modgps_on_update(mp_obj_t callable) {
+    // ========================================
+    // Sets a callback on GPS update.
+    // Args:
+    //     callback (Callable): a callback to
+    //     execute on GPS data received from UART.
+    // ========================================
+    gps_callback = callable;
+    return mp_const_none;
 }
 
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(modgps_on_update_obj, modgps_on_update);
+
 // -------
 // Methods
 // -------
 
+#define USE_GPS 1
+#define USE_GLONASS 2
+#define USE_BEIDOU 4
+#define USE_GALILEO 8
+
 STATIC mp_obj_t modgps_on(size_t n_args, const mp_obj_t *arg) {
     // ========================================
     // Turns GPS on.
     // Args:
     //     timeout (int): timeout in seconds;
+    //     mode(int): navigation systems to use, GPS, GLONASS, BEIDOU, GALILEO as bitmask
     // Raises:
     //     ValueError if failed to turn GPS on.
     // ========================================
     uint32_t timeout = 0;
+    uint8_t search_mode = USE_GPS;
+
     if (n_args == 0) {
         timeout = DEFAULT_GPS_TIMEOUT;
-    } else {
+    }
+    else  {
         timeout = mp_obj_get_int(arg[0]);
+
+        if (n_args == 2) {
+            search_mode = mp_obj_get_int(arg[1]);
+        }
+
     }
+
     timeout *= 1000 * CLOCKS_PER_MSEC;
     gpsInfo = Gps_GetInfo();
     gpsInfo->rmc.latitude.value = 0;
     gpsInfo->rmc.longitude.value = 0;
     GPS_Init();
     GPS_Open(NULL);
+
+    GPS_SetSearchMode(!!(search_mode & USE_GPS), !!(search_mode & USE_GLONASS),
+                     !!(search_mode & USE_BEIDOU), !!(search_mode & USE_GALILEO));
+
     WAIT_UNTIL(gpsInfo->rmc.latitude.value, timeout, 100, mp_raise_OSError(MP_ETIMEDOUT));
+
     return mp_const_none;
 }
 
-STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(modgps_on_obj, 0, 1, modgps_on);
+STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(modgps_on_obj, 0, 2, modgps_on);
 
 STATIC mp_obj_t modgps_off(void) {
     // ========================================
@@ -357,6 +396,12 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_0(modgps_nmea_data_obj, modgps_nmea_data);
 STATIC const mp_map_elem_t mp_module_gps_globals_table[] = {
     { MP_OBJ_NEW_QSTR(MP_QSTR___name__), MP_OBJ_NEW_QSTR(MP_QSTR_gps) },
 
+    // GNSS
+    { MP_ROM_QSTR(MP_QSTR_GLONASS),          MP_ROM_INT(USE_GLONASS) },
+    { MP_ROM_QSTR(MP_QSTR_GPS),              MP_ROM_INT(USE_GPS) },
+    { MP_ROM_QSTR(MP_QSTR_GALILEO),          MP_ROM_INT(USE_GALILEO) },
+    { MP_ROM_QSTR(MP_QSTR_BEIDOU),           MP_ROM_INT(USE_BEIDOU) },
+
     { MP_OBJ_NEW_QSTR(MP_QSTR_on), (mp_obj_t)&modgps_on_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_off), (mp_obj_t)&modgps_off_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_get_firmware_version), (mp_obj_t)&modgps_get_firmware_version_obj },
@@ -365,6 +410,7 @@ STATIC const mp_map_elem_t mp_module_gps_globals_table[] = {
     { MP_OBJ_NEW_QSTR(MP_QSTR_get_satellites), (mp_obj_t)&modgps_get_satellites_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_time), (mp_obj_t)&modgps_time_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_nmea_data), (mp_obj_t)&modgps_nmea_data_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_on_update), (mp_obj_t)&modgps_on_update},
 };
 
 STATIC MP_DEFINE_CONST_DICT(mp_module_gps_globals, mp_module_gps_globals_table);