Merge pull request #1138 from UncleGrumpy/rssi

Add new function to obtain connection RSSI info

These changes add support for both ESP32 and Pico-W to obtain the current signal
strength (in decibels) of the connection to the associated access point using
`network:sta_rssi/0`.

These changes are made under both the "Apache 2.0" and the "GNU Lesser General
Public License 2.1 or later" license terms (dual license).

SPDX-License-Identifier: Apache-2.0 OR LGPL-2.1-or-later

CHANGELOG.md

@@ -12,6 +12,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Added guards `is_even` and `is_odd` to the `Integer` module
 - Add a number of functions to proplists module, such as `delete/2`, `from/to_map/1`, etc...
 - Add `esp:deep_sleep_enable_gpio_wakeup/2` to allow wakeup from deep sleep for ESP32C3 and ESP32C6.
+- Obtain RSSI of the current connection with `network:sta_rssi/0` on ESP32.
+- Pico-W support for `network:sta_rssi/0`.
 
 ### Fixed
 

doc/src/network-programming-guide.md

@@ -99,6 +99,8 @@ case network:wait_for_sta(Config, 15000) of
 end
 ```
 
+To obtain the signal strength (in decibels) of the connection to the associated access point use [`network:sta_rssi/0`](./apidocs/erlang/eavmlib/network.md#sta_rssi0).
+
 ## AP mode
 
 In AP mode, the ESP32 starts a WiFi network to which other devices (laptops, mobile devices, other ESP32 devices, etc) can connect. The ESP32 will create an IPv4 network, and will assign itself the address `192.168.4.1`. Devices that attach to the ESP32 in AP mode will be assigned sequential addresses in the `192.168.4.0/24` range, e.g., `192.168.4.2`, `192.168.4.3`, etc.

libs/eavmlib/src/network.erl

@@ -24,7 +24,8 @@
 
 -export([
  wait_for_sta/0, wait_for_sta/1, wait_for_sta/2,
- wait_for_ap/0, wait_for_ap/1, wait_for_ap/2
+ wait_for_ap/0, wait_for_ap/1, wait_for_ap/2,
+ sta_rssi/0
 ]).
 -export([start/1, start_link/1, stop/0]).
 -export([
@@ -88,6 +89,8 @@
 
 -type network_config() :: [sta_config() | ap_config() | sntp_config()].
 
+-type db() :: integer().
+
 -record(state, {
  config :: network_config(),
  port :: port(),
@@ -247,6 +250,23 @@ start_link(Config) ->
 stop() ->
  gen_server:stop(?SERVER).
 
+%%-----------------------------------------------------------------------------
+%% @returns {ok, Rssi} in decibels, or {error, Reason}.
+%%
+%% @doc Get the rssi information of AP to which the device is associated with.
+%% @end
+%%-----------------------------------------------------------------------------
+-spec sta_rssi() -> {ok, Rssi :: db()} | {error, Reason :: term()}.
+sta_rssi() ->
+ Port = get_port(),
+ Ref = make_ref(),
+ Port ! {self(), Ref, rssi},
+ receive
+ {Ref, {error, Reason}} -> {error, Reason};
+ {Ref, {rssi, Rssi}} -> {ok, Rssi};
+ Other -> {error, Other}
+ end.
+
 %%
 %% gen_server callbacks
 %%

src/platforms/esp32/components/avm_builtins/network_driver.c

@@ -86,11 +86,13 @@ enum network_cmd
 {
  NetworkInvalidCmd = 0,
  // TODO add support for scan, ifconfig
- NetworkStartCmd
+ NetworkStartCmd,
+ NetworkRssiCmd
 };
 
 static const AtomStringIntPair cmd_table[] = {
  { ATOM_STR("\x5", "start"), NetworkStartCmd },
+ { ATOM_STR("\x4", "rssi"), NetworkRssiCmd },
  SELECT_INT_DEFAULT(NetworkInvalidCmd)
 };
 
@@ -761,6 +763,29 @@ static void start_network(Context *ctx, term pid, term ref, term config)
  port_send_reply(ctx, pid, ref, OK_ATOM);
 }
 
+static void get_sta_rssi(Context *ctx, term pid, term ref)
+{
+ size_t tuple_reply_size = PORT_REPLY_SIZE + TUPLE_SIZE(2);
+
+ int sta_rssi = 0;
+ esp_err_t err = esp_wifi_sta_get_rssi(&sta_rssi);
+ if (UNLIKELY(err != ESP_OK)) {
+ term error_term = term_from_int(err);
+ ESP_LOGE(TAG, "error obtaining RSSI: [%i] %u", err, error_term);
+ // Reply: {Ref, {error, Reason}}
+ port_ensure_available(ctx, tuple_reply_size);
+ term error = port_create_error_tuple(ctx, error_term);
+ port_send_reply(ctx, pid, ref, error);
+ return;
+ }
+ term rssi = term_from_int(sta_rssi);
+ // {Ref, {rssi, -25}}
+ port_ensure_available(ctx, tuple_reply_size);
+ term reply = port_create_tuple2(ctx, make_atom(ctx->global, ATOM_STR("\x4", "rssi")), rssi);
+ port_send_reply(ctx, pid, ref, reply);
+
+}
+
 static NativeHandlerResult consume_mailbox(Context *ctx)
 {
  Message *message = mailbox_first(&ctx->mailbox);
@@ -775,17 +800,26 @@ static NativeHandlerResult consume_mailbox(Context *ctx)
  term pid = term_get_tuple_element(msg, 0);
  term ref = term_get_tuple_element(msg, 1);
  term cmd = term_get_tuple_element(msg, 2);
+ term cmd_term = term_invalid_term();
+ term config = term_invalid_term();
 
- if (term_is_tuple(cmd) && term_get_tuple_arity(cmd) == 2) {
+ if ((term_is_tuple(cmd) && term_get_tuple_arity(cmd) == 2) || term_is_atom(cmd)) {
 
- term cmd_term = term_get_tuple_element(cmd, 0);
- term config = term_get_tuple_element(cmd, 1);
+ if (term_is_atom(cmd)) {
+ cmd_term = cmd;
+ } else {
+ cmd_term = term_get_tuple_element(cmd, 0);
+ config = term_get_tuple_element(cmd, 1);
+ }
 
  enum network_cmd cmd = interop_atom_term_select_int(cmd_table, cmd_term, ctx->global);
  switch (cmd) {
  case NetworkStartCmd:
  start_network(ctx, pid, ref, config);
  break;
+ case NetworkRssiCmd:
+ get_sta_rssi(ctx, pid, ref);
+ break;
 
  default: {
  ESP_LOGE(TAG, "Unrecognized command: %x", cmd);

src/platforms/rp2040/src/lib/gpiodriver.c

@@ -24,6 +24,9 @@
 #include <string.h>
 
 #include <hardware/gpio.h>
+#ifdef LIB_PICO_CYW43_ARCH
+#include <pico/cyw43_arch.h>
+#endif
 
 #include "defaultatoms.h"
 #include "interop.h"

src/platforms/rp2040/src/lib/networkdriver.c

@@ -58,11 +58,13 @@ enum network_cmd
 {
  NetworkInvalidCmd = 0,
  // TODO add support for scan, ifconfig
- NetworkStartCmd
+ NetworkStartCmd,
+ NetworkRssiCmd
 };
 
 static const AtomStringIntPair cmd_table[] = {
  { ATOM_STR("\x5", "start"), NetworkStartCmd },
+ { ATOM_STR("\x4", "rssi"), NetworkRssiCmd },
  SELECT_INT_DEFAULT(NetworkInvalidCmd)
 };
 
@@ -602,6 +604,27 @@ static void start_network(Context *ctx, term pid, term ref, term config)
  port_send_reply(ctx, pid, ref, OK_ATOM);
 }
 
+static void get_sta_rssi(Context *ctx, term pid, term ref)
+{
+ size_t tuple_reply_size = PORT_REPLY_SIZE + TUPLE_SIZE(2);
+
+ int32_t sta_rssi = 0;
+ int err = cyw43_wifi_get_rssi(&cyw43_state, &sta_rssi);
+ if (UNLIKELY(err != 0)) {
+ // Reply: {Ref, {error, Reason}}
+ port_ensure_available(ctx, tuple_reply_size);
+ term error = port_create_error_tuple(ctx, term_from_int(err));
+ port_send_reply(ctx, pid, ref, error);
+ return;
+ }
+
+ term rssi = term_from_int32(sta_rssi);
+ // Reply: {Ref, {rssi, Value}}
+ port_ensure_available(ctx, tuple_reply_size);
+ term reply = port_create_tuple2(ctx, globalcontext_make_atom(ctx->global, ATOM_STR("\x4", "rssi")), rssi);
+ port_send_reply(ctx, pid, ref, reply);
+}
+
 static NativeHandlerResult consume_mailbox(Context *ctx)
 {
  Message *message = mailbox_first(&ctx->mailbox);
@@ -614,17 +637,27 @@ static NativeHandlerResult consume_mailbox(Context *ctx)
  term pid = term_get_tuple_element(msg, 0);
  term ref = term_get_tuple_element(msg, 1);
  term cmd = term_get_tuple_element(msg, 2);
+ term cmd_term = term_invalid_term();
+ term config = term_invalid_term();
 
- if (term_is_tuple(cmd) && term_get_tuple_arity(cmd) == 2) {
-
- term cmd_term = term_get_tuple_element(cmd, 0);
- term config = term_get_tuple_element(cmd, 1);
+ if ((term_is_tuple(cmd) && term_get_tuple_arity(cmd) == 2) || term_is_atom(cmd)) {
+ if (term_is_atom(cmd)) {
+ cmd_term = cmd;
+ } else {
+ cmd_term = term_get_tuple_element(cmd, 0);
+ config = term_get_tuple_element(cmd, 1);
+ }
 
- enum network_cmd cmd = interop_atom_term_select_int(cmd_table, cmd_term, ctx->global);
- switch (cmd) {
- case NetworkStartCmd:
+ enum network_cmd command = interop_atom_term_select_int(cmd_table, cmd_term, ctx->global);
+ switch (command) {
+ case NetworkStartCmd: {
  start_network(ctx, pid, ref, config);
  break;
+ }
+ case NetworkRssiCmd: {
+ get_sta_rssi(ctx, pid, ref);
+ break;
+ }
 
  default: {
  // {Ref, {error, badarg}}