Add method to set the WiFi radio channel (#9405)

* Add method to set the WiFi radio channel

* Fix Tab

* Add check

* Change name

* Fix description

* Add check

* Add error return

* Improve error message

libraries/WiFi/src/WiFiGeneric.cpp

@@ -1269,6 +1269,40 @@ int32_t WiFiGenericClass::channel(void)
     return primaryChan;
 }
 
+/**
+ * Set the WiFi channel configuration
+ * @param primary primary channel. Depending on the region, not all channels may be available.
+ * @param secondary secondary channel (WIFI_SECOND_CHAN_NONE, WIFI_SECOND_CHAN_ABOVE, WIFI_SECOND_CHAN_BELOW)
+ * @return 0 on success, otherwise error
+ */
+int WiFiGenericClass::setChannel(uint8_t primary, wifi_second_chan_t secondary)
+{
+    wifi_country_t country;
+    esp_err_t ret;
+
+    ret = esp_wifi_get_country(&country);
+    if (ret != ESP_OK) {
+        log_e("Failed to get country info");
+        return ret;
+    }
+
+    uint8_t min_chan = country.schan;
+    uint8_t max_chan = min_chan + country.nchan - 1;
+
+    if(primary < min_chan || primary > max_chan){
+        log_e("Invalid primary channel: %d. Valid range is %d-%d for country %s", primary, min_chan, max_chan, country.cc);
+        return ESP_ERR_INVALID_ARG;
+    }
+
+    ret = esp_wifi_set_channel(primary, secondary);
+    if (ret != ESP_OK) {
+        log_e("Failed to set channel");
+        return ret;
+    }
+
+    return ESP_OK;
+}
+
 /**
  * store WiFi config in SDK flash area
  * @param persistent

libraries/WiFi/src/WiFiGeneric.h

@@ -183,6 +183,7 @@ class WiFiGenericClass
     static int waitStatusBits(int bits, uint32_t timeout_ms);
 
     int32_t channel(void);
+    int setChannel(uint8_t primary, wifi_second_chan_t secondary=WIFI_SECOND_CHAN_NONE);
 
     void persistent(bool persistent);
     void enableLongRange(bool enable);