Feature: Add signal strength function (#93)

* add function to get signal strength

* handle error case in ublox and return i8

src/asynch/control.rs

@@ -195,6 +195,22 @@ impl<'a, const INGRESS_BUF_SIZE: usize, const URC_CAPACITY: usize>
         }
     }
 
+    pub async fn get_signal_strength(&self) -> Result<i8, Error> {
+        match (&self.at_client)
+            .send_retry(&GetWifiStatus {
+                status_id: StatusId::Rssi,
+            })
+            .await?
+            .status_id
+        {
+            WifiStatus::Rssi(-32768) => Err(Error::NotConnected),
+            WifiStatus::Rssi(s) => s
+                .try_into()
+                .map_err(|_| Error::AT(atat::Error::InvalidResponse)),
+            _ => Err(Error::AT(atat::Error::InvalidResponse)),
+        }
+    }
+
     pub async fn wait_for_link_state(&self, link_state: LinkState) {
         self.state_ch.wait_for_link_state(link_state).await
     }

src/command/wifi/types.rs

@@ -499,7 +499,7 @@ pub enum WifiStatus {
     /// The <status_val> is the RSSI value of the current connection; will
     /// return-32768, if not connected.
     #[at_arg(value = 6)]
-    Rssi(u32),
+    Rssi(i16),
     /// The <status_val> is the mobility domain of the last or current
     /// connection This tag is supported by ODIN-W2 from software version 6.0.0
     /// onwards only.

src/error.rs

@@ -34,6 +34,7 @@ pub enum Error {
     Timeout,
     ShadowStoreBug,
     AlreadyConnected,
+    NotConnected,
     _Unknown,
 }