Add WiFi.channel() reporting (#937)

Also return error conditions when WiFi status is inquired while not
connected.

Author: earlephilhower

docs/wifi.rst

@@ -40,8 +40,6 @@ Please note that WiFi on the Pico W is a work-in-progress and there are some imp
 
   * Combined STA/AP mode is not supported
 
-  * Certain WiFi status values (RSSI, BSSID, etc.) are not available.
-
 * Multicore is supported, but only one core may run ``WiFi`` code.
 
   * FreeRTOS is not yet supported due to the requirement for a very different LWIP implementation.  PRs always appreciated!

libraries/WiFi/keywords.txt

@@ -42,6 +42,7 @@ gatewayIP	KEYWORD2
 SSID	KEYWORD2
 BSSID		KEYWORD2
 RSSI	KEYWORD2
+channel	KEYWORD2
 encryptionType	KEYWORD2
 beginPacket	KEYWORD2
 endPacket	KEYWORD2

libraries/WiFi/src/WiFiClass.cpp

@@ -314,10 +314,30 @@ uint8_t* WiFiClass::BSSID(uint8_t* bssid) {
 #ifndef CYW43_IOCTL_GET_BSSID
 #define CYW43_IOCTL_GET_BSSID ( (uint32_t)23 * 2 )
 #endif
-    cyw43_ioctl(&cyw43_state, CYW43_IOCTL_GET_BSSID, WL_MAC_ADDR_LENGTH, bssid, CYW43_ITF_STA);
+
+    if (_wifi.connected()) {
+        cyw43_ioctl(&cyw43_state, CYW43_IOCTL_GET_BSSID, WL_MAC_ADDR_LENGTH, bssid, CYW43_ITF_STA);
+    } else {
+        memset(bssid, 0, WL_MAC_ADDR_LENGTH);
+    }
     return bssid;
 }
 
+int WiFiClass::channel() {
+#ifndef CYW43_IOCTL_GET_CHANNEL
+#define CYW43_IOCTL_GET_CHANNEL 0x3a
+#endif
+
+    int32_t channel;
+    if (_wifi.connected()) {
+        cyw43_ioctl(&cyw43_state, CYW43_IOCTL_GET_CHANNEL, sizeof channel, (uint8_t *)&channel, CYW43_ITF_STA);
+    } else {
+        channel = -1;
+    }
+    return channel;
+}
+
+
 /*
     Return the current RSSI /Received Signal Strength in dBm)
     associated with the network
@@ -330,7 +350,11 @@ int32_t WiFiClass::RSSI() {
 #endif
 
     int32_t rssi;
-    cyw43_ioctl(&cyw43_state, CYW43_IOCTL_GET_RSSI, sizeof rssi, (uint8_t *)&rssi, CYW43_ITF_STA);
+    if (_wifi.connected()) {
+        cyw43_ioctl(&cyw43_state, CYW43_IOCTL_GET_RSSI, sizeof rssi, (uint8_t *)&rssi, CYW43_ITF_STA);
+    } else {
+        rssi = -255;
+    }
     return rssi;
 }
 

libraries/WiFi/src/WiFiClass.h

@@ -267,6 +267,10 @@ class WiFiClass {
     */
     int32_t RSSI();
 
+
+    /* Return the current network channel */
+    int channel();
+
     /*
         Return the Encryption Type associated with the network