diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index cc5ad4f7bc874..0dbccdf4dde11 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -467,7 +467,7 @@ jobs:
       id: idf-cache
       with:
         path: ${{ github.workspace }}/.idf_tools
-        key: ${{ runner.os }}-idf-tools-${{ hashFiles('.git/modules/ports/esp32s2/esp-idf/HEAD') }}-20210121
+        key: ${{ runner.os }}-idf-tools-${{ hashFiles('.git/modules/ports/esp32s2/esp-idf/HEAD') }}-20210122
     - name: Clone IDF submodules
       run: |
         (cd $IDF_PATH && git submodule update --init)
diff --git a/locale/circuitpython.pot b/locale/circuitpython.pot
index 259cd34d4512d..3ffc31cc6cae0 100644
--- a/locale/circuitpython.pot
+++ b/locale/circuitpython.pot
@@ -3930,6 +3930,10 @@ msgstr ""
 msgid "width must be greater than zero"
 msgstr ""
 
+#: ports/esp32s2/common-hal/wifi/Radio.c
+msgid "wifi is not enabled"
+msgstr ""
+
 #: shared-bindings/_bleio/Adapter.c
 msgid "window must be <= interval"
 msgstr ""
diff --git a/ports/esp32s2/common-hal/wifi/Radio.c b/ports/esp32s2/common-hal/wifi/Radio.c
index 9302300889722..574bab0a1912f 100644
--- a/ports/esp32s2/common-hal/wifi/Radio.c
+++ b/ports/esp32s2/common-hal/wifi/Radio.c
@@ -72,7 +72,7 @@ void common_hal_wifi_radio_set_enabled(wifi_radio_obj_t *self, bool enabled) {
     }
     if (!self->started && enabled) {
 	// esp_wifi_start() would default to soft-AP, thus setting it to station
-        ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
+        start_station(self);
         ESP_ERROR_CHECK(esp_wifi_start());
         self->started = true;
         return;
@@ -89,7 +89,9 @@ mp_obj_t common_hal_wifi_radio_start_scanning_networks(wifi_radio_obj_t *self) {
     if (self->current_scan != NULL) {
         mp_raise_RuntimeError(translate("Already scanning for wifi networks"));
     }
-    // check enabled
+    if (!common_hal_wifi_radio_get_enabled(self)) {
+        mp_raise_RuntimeError(translate("wifi is not enabled"));
+    }
     start_station(self);
 
     wifi_scannednetworks_obj_t *scan = m_new_obj(wifi_scannednetworks_obj_t);
@@ -126,7 +128,25 @@ void common_hal_wifi_radio_set_hostname(wifi_radio_obj_t *self, const char *host
 }
 
 wifi_radio_error_t common_hal_wifi_radio_connect(wifi_radio_obj_t *self, uint8_t* ssid, size_t ssid_len, uint8_t* password, size_t password_len, uint8_t channel, mp_float_t timeout, uint8_t* bssid, size_t bssid_len) {
-    // check enabled
+    if (!common_hal_wifi_radio_get_enabled(self)) {
+        mp_raise_RuntimeError(translate("wifi is not enabled"));
+    }
+
+    EventBits_t bits;
+    // can't block since both bits are false after wifi_init
+    // both bits are true after an existing connection stops
+    bits = xEventGroupWaitBits(self->event_group_handle,
+        WIFI_CONNECTED_BIT | WIFI_DISCONNECTED_BIT,
+        pdTRUE,
+        pdTRUE,
+        0);
+    if (((bits & WIFI_CONNECTED_BIT) != 0) &&
+        !((bits & WIFI_DISCONNECTED_BIT) != 0)) {
+        return WIFI_RADIO_ERROR_NONE;
+    }
+    // explicitly clear bits since xEventGroupWaitBits may have timed out
+    xEventGroupClearBits(self->event_group_handle, WIFI_CONNECTED_BIT);
+    xEventGroupClearBits(self->event_group_handle, WIFI_DISCONNECTED_BIT);
     start_station(self);
 
     wifi_config_t* config = &self->sta_config;
@@ -157,7 +177,6 @@ wifi_radio_error_t common_hal_wifi_radio_connect(wifi_radio_obj_t *self, uint8_t
     self->retries_left = 5;
     esp_wifi_connect();
 
-    EventBits_t bits;
     do {
         RUN_BACKGROUND_TASKS;
         bits = xEventGroupWaitBits(self->event_group_handle,