Fetch online states only, when panel is online

client/bin/Cargo.toml

@@ -21,3 +21,4 @@ serde = "1.0"
 serde_derive = "1.0"
 serde_json = "1.0"
 # end of web stuff
+ping = "0.4.1"

client/bin/src/main.rs

@@ -1,4 +1,4 @@
-
+use std::time::Duration;
 use bit::BitIndex;
 use chrono_tz::Europe::Berlin;
 use chrono::{DateTime, NaiveDateTime, Utc, Timelike};
@@ -21,6 +21,7 @@ use std::{env, thread};
 
 use openweathermap::forecast::Forecast;
 use straba::NextDeparture;
+use ping;
 // This declaration will look for a file named `straba.rs` and will
 // insert its contents inside a module named `straba` under this scope
 mod straba;
@@ -310,13 +311,15 @@ fn main() {
 
             // Render start
             send_package(ip.to_string(), &last_data, &strabaRes);
+            let mut device_online = true;
             loop {
                 let st_now = SystemTime::now();
                 let seconds = st_now.duration_since(UNIX_EPOCH).unwrap().as_secs();
                 let delay = time::Duration::from_millis(10000);
                 thread::sleep(delay);
+                // Only request, if the device is present
+                if device_online == true {
                     let answer = openweathermap::update_forecast(&receiver);
-
                     match answer {
                         Some(_) => {
                             last_data = answer;
@@ -325,17 +328,37 @@ fn main() {
 
                         }
                     }
+                }
+
+                if (strabaRes.request_time + 60) < seconds as i64 {
+                    // check once a minute if the panel is online
+                    let data: [u8; 24] = [0;24];  // ping data
+                    let result = ping::ping(ip.parse().unwrap(), Some(Duration::from_secs(1)),
+                                Some(128), Some(0), Some(0), Some(&data));
+                    match result {
+                        Ok(_) =>{
+                            device_online = true;
+                        }
+                        Err(e) => {
+                            device_online = false;
+                            println!("{} is offline, {:?}", &ip, e)
+                        }
+                    }
 
                     // request once a minute new data
-                if (strabaRes.request_time + 60) < seconds as i64 {
+                    if device_online == true {
                         strabaRes = straba::fetch_data(None);
                         println!("Update {:?} {:?}s", strabaRes.outbound_station, strabaRes.outbound_diff);
                         println!("Update {:?} {:?}s", strabaRes.inbound_station , strabaRes.inbound_diff);
                     }
+                }
+
+                if device_online == true {
                     // Render new image
                     send_package(ip.to_string(), &last_data, &strabaRes);
                 }
             }
+        }
         // all the other cases
         _ => {
             // show a help message