Add network:wifi_scan/0,1 to esp32 network driver

Signed-off-by: Winford <winford@object.stream>

Author: UncleGrumpy

CHANGELOG.md

@@ -87,6 +87,7 @@ encoding/decoding options, also Elixir `(url_)encode64`/`(url_)decode64` have be
 - Added `nanosecond` and `native` time unit support to `erlang:system_time/1`, `erlang:monotonic_time/1`, and `calendar:system_time_to_universal_time/2`
 - Added `erlang:system_time/0`, `erlang:monotonic_time/0`, and `os:system_time/0,1` NIFs
 - Added `filename:join/1` and `filename:split/1`
+- Added `network:wifi_scan/0,1` to ESP32 network driver to scan available APs when in sta or sta+ap mode.
 
 ### Changed
 

examples/erlang/esp32/CMakeLists.txt

@@ -38,3 +38,5 @@ pack_runnable(reformat_nvs reformat_nvs eavmlib avm_esp32)
 pack_runnable(uartecho uartecho eavmlib estdlib avm_esp32)
 pack_runnable(ledc_example ledc_example eavmlib estdlib avm_esp32)
 pack_runnable(epmd_disterl epmd_disterl eavmlib estdlib avm_network avm_esp32)
+pack_runnable(wifi_scan wifi_scan estdlib eavmlib avm_network avm_esp32)
+pack_runnable(wifi_scan_callback wifi_scan_callback estdlib eavmlib avm_network avm_esp32)

examples/erlang/esp32/wifi_scan.erl

@@ -0,0 +1,70 @@
+%% This file is part of AtomVM.
+%%
+%% Copyright (c) 2023 <winford@object.stream>
+%% All rights reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%%
+%% SPDX-License-Identifier: Apache-2.0 OR LGPL-2.1-or-later
+%%
+
+-module(wifi_scan).
+
+-export([start/0]).
+
+start() ->
+    {ok, _Pid} = network:start([{sta, [managed]}]),
+    scan_passive([show_hidden, {dwell, 1000}]),
+    scan_active([{dwell, 500}]).
+
+scan_active(Config) ->
+    io:format(
+        "~nStarting active scan with configuration ~p, this may take some time depending on dwell ms used.~n~n",
+        [Config]
+    ),
+    BeginTime = erlang:monotonic_time(millisecond),
+    {ok, {Num, Networks}} = network:wifi_scan(Config),
+    io:format("Active scan found ~p networks in ~pms.~n", [
+        Num, erlang:monotonic_time(millisecond) - BeginTime
+    ]),
+    format_networks(Networks).
+
+scan_passive(Config) ->
+    io:format(
+        "~nStarting passive scan with configuration: ~p, this may take some time depending on dwell ms used.~n~n",
+        [Config]
+    ),
+    Opts = [passive | Config],
+    BeginTime = erlang:monotonic_time(millisecond),
+    ScanResults = network:wifi_scan(Opts),
+    {ok, {Num, Networks}} = ScanResults,
+    io:format("Passive scan found ~p networks in ~pms.~n", [
+        Num, erlang:monotonic_time(millisecond) - BeginTime
+    ]),
+    format_networks(Networks).
+
+format_networks(Networks) ->
+    lists:foreach(
+        fun(
+            _Network = #{
+                ssid := SSID, rssi := DBm, authmode := Mode, bssid := BSSID, channel := Number
+            }
+        ) ->
+            io:format(
+                "Network: ~p, BSSID: ~p, signal ~p dBm, Security: ~p, channel ~p~n",
+                [SSID, binary:encode_hex(BSSID), DBm, Mode, Number]
+            )
+        end,
+        Networks
+    ).

examples/erlang/esp32/wifi_scan_callback.erl

@@ -0,0 +1,63 @@
+%% This file is part of AtomVM.
+%%
+%% Copyright (c) 2023 <winford@object.stream>
+%% All rights reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%%
+%% SPDX-License-Identifier: Apache-2.0 OR LGPL-2.1-or-later
+%%
+
+-module(wifi_scan_callback).
+
+-export([start/0]).
+
+start() ->
+    Config = [{sta, [managed, {scan_done, fun display_scan_results/1}]}],
+    {ok, _Pid} = network:start(Config),
+    io:format(
+        "~nStarting active scan with configuration ~p, this may take some time depending on dwell ms used.~n~n",
+        [Config]
+    ),
+    case network:wifi_scan() of
+        {error, Reason} ->
+            io:format("wifi_scan failed for reason ~p", [Reason]);
+        ok ->
+            timer:sleep(infinity)
+    end.
+
+display_scan_results(Results) ->
+    case Results of
+        {error, Reason} ->
+            io:format("wifi_scan failed for reason ~p.~n", [Reason]);
+        {Num, Networks} ->
+            io:format("wifi_scan callback got ~p results:~n", [Num]),
+            lists:foreach(
+                fun(
+                    _Network = #{
+                        ssid := SSID,
+                        rssi := DBm,
+                        authmode := Mode,
+                        bssid := BSSID,
+                        channel := Number
+                    }
+                ) ->
+                    io:format(
+                        "Network: ~s, BSSID: ~s, signal ~p dBm, Security: ~p, channel ~p~n",
+                        [SSID, binary:encode_hex(BSSID), DBm, Mode, Number]
+                    )
+                end,
+                Networks
+            )
+    end.