diff --git a/build.rs b/build.rs
index 5efe9c9..1717f27 100644
--- a/build.rs
+++ b/build.rs
@@ -1,3 +1,4 @@
 fn main() {
     println!("cargo:rustc-link-arg-bins=-Tlinkall.x");
+    println!("cargo:rustc-env=CARGO_PKG_VERSION_SAFE={}", env!("CARGO_PKG_VERSION").replace(".", "_"));
 }
diff --git a/src/httpd.rs b/src/httpd.rs
index d77e45c..0e685c5 100644
--- a/src/httpd.rs
+++ b/src/httpd.rs
@@ -12,6 +12,9 @@ use include_file_compress::include_file_compress_deflate;
 
 use crate::database::DATAPOINT_BUFFER;
 
+const STYLES_CSS_FILENAME: &str = concat!("/styles-", env!("CARGO_PKG_VERSION_SAFE"), ".css");
+const APP_JS_FILENAME: &str = concat!("/app-", env!("CARGO_PKG_VERSION_SAFE"), ".css");
+
 static PICO_CONFIG : picoserve::Config<Duration> = picoserve::Config::new(
     picoserve::Timeouts {
         start_read_request: Some(Duration::from_secs(5)),
@@ -52,9 +55,9 @@ async fn web_task(
         picoserve::Router::new()
         .nest("/api/v1", api_router)
         .route("/", get(|| async { index() }))
-        .route("/styles.css", get_service(File::with_content_type_and_headers(&CSS_CONTENT_TYPE, 
+        .route(STYLES_CSS_FILENAME, get_service(File::with_content_type_and_headers(&CSS_CONTENT_TYPE, 
                                           include_file_compress_deflate!("src/static/styles.css", 5), DEFLATE_CACHEABLE_CONTENT_HEADERS)))
-        .route("/app.js", get_service(File::with_content_type_and_headers(&JS_CONTENT_TYPE,
+        .route(APP_JS_FILENAME, get_service(File::with_content_type_and_headers(&JS_CONTENT_TYPE,
                                       include_file_compress_deflate!("src/static/app.js", 5), DEFLATE_CACHEABLE_CONTENT_HEADERS)))
         .nest("/images", image_router);
 
@@ -81,8 +84,8 @@ fn page(heading: &str, content: Markup) -> Markup {
         (DOCTYPE)
         html {
         head {
-            link rel="stylesheet" type="text/css" href="/styles.css";
-            script src="app.js" {};
+            link rel="stylesheet" type="text/css" href=(STYLES_CSS_FILENAME);
+            script src=(APP_JS_FILENAME) {};
             title { (heading) }
         }
         body {
@@ -191,7 +194,7 @@ fn latest() -> impl IntoResponse {
 fn index() -> impl IntoResponse {
   page("Wallas 22GB Wifi Extension", html! {
       p .intro { "Beta version of ESP32C3 based Wifi extension to the Wallas 361062 Control Panel for the DT/GB Heaters" }
+      p #graph { "Waiting for data ..." }
       p #latest { "Waiting for latest reading ..." }
-      // p { "Time is now " (get_now()) }
   })
 }
diff --git a/src/main.rs b/src/main.rs
index 50ae80f..30d877c 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -59,6 +59,10 @@ mod database;
 use database::database_spawn;
 
 
+/// CARGO_PKG_VERSION
+pub const VERSION: &str = env!("CARGO_PKG_VERSION");
+pub const VERSION_SAFE: &str = env!("CARGO_PKG_VERSION_SAFE");
+
 /// SSID for WiFi network
 const WIFI_SSID: &str = env!("WIFI_SSID");
 
@@ -78,7 +82,7 @@ const MAX_CONCURRENT_SOCKETS: usize = HTTPD_SOCKETS + DHCP_SOCKETS + DNS_SOCKETS
 #[main]
 async fn main(spawner: Spawner) {
 
-    info!("booting firmware");
+    info!("booting firmware version {}", VERSION);
 
     if let Err(error) = main_fallible(spawner).await {
         error!("Error while running firmware: {error:?}");
diff --git a/src/static/app.js b/src/static/app.js
index 0a7e3dd..5b29082 100644
--- a/src/static/app.js
+++ b/src/static/app.js
@@ -4,20 +4,69 @@ function sleep(ms) {
   return new Promise(resolve => setTimeout(resolve, ms));
 }
 
-document.addEventListener("DOMContentLoaded", () => DOMLoaded(), false);
+document.addEventListener("DOMContentLoaded", () => LoadCurrent(), false);
+document.addEventListener("DOMContentLoaded", () => LoadGraph(), false);
 
-async function DOMLoaded() {
-  await sleep(1000);
+async function LoadCurrent() {
+  await sleep(500);
   while (true) {
-      fetch("/api/v1/latest").then((response) => response.json()).then((json) => {
-          if (json.time) {
-              time = json.time;
-              temperature = json.temperature;
-              target = json.target;
-              document.getElementById("latest").innerHTML = `Temperature was ${temperature}&deg;C at ${time} UTC, target temperature was ${target}&deg;C`;
-          }
-      })
+    fetch("/api/v1/latest").then((response) => response.json()).then((json) => {
+      if (json.time) {
+        time = json.time;
+        temperature = json.temperature;
+        target = json.target;
+        document.getElementById("latest").innerHTML = `Temperature was ${temperature}&deg;C at ${time} UTC, target temperature was ${target}&deg;C`;
+      }
+    })
     await sleep(10000);
   }
 };
 
+const svg_xmlns = "http://www.w3.org/2000/svg";
+function appendSVGElement(parent, name, attributes) {
+  var elem = document.createElementNS(svg_xmlns, name);
+  for (var aname in attributes) {
+    elem.setAttributeNS(null, aname, attributes[aname]);
+  }
+  parent.appendChild(elem);
+  return elem;
+}
+
+async function LoadGraph() {
+  await sleep(1000);
+  while (true) {
+    fetch("/api/v1/allreadings").then((response) => response.json()).then((json) => {
+      if (json instanceof Array && json.length > 0) {
+        var graph = document.createDocumentFragment();
+        var svg = appendSVGElement(graph, "svg", {"width": "100%", "height": "100%", "viewBox": "0 0 100 35"});
+        var x = 99;
+        var target_points = [];
+        var temperature_points = [];
+        for (var i = json.length - 1; i > 0; i--) {
+          var r = json[i];
+          var temperature_y = 25 - r.temperature;
+          temperature_points.push(`${x},${temperature_y}`);
+          var target_y = 25 - r.target;
+          target_points.push(`${x},${target_y}`);
+          x = x - 1;
+        }
+        temperature_points_str = temperature_points.join(" ");
+        target_points_str = target_points.join(" ");
+
+        // zero line
+        appendSVGElement(svg, "polyline", {"stroke-width": "0.1", "fill": "none", "stroke":"#000080", "stroke-linecap": "round", "stroke-dasharray": "5,2", "points": "1,25 99,25"});
+        // ten line
+        appendSVGElement(svg, "polyline", {"stroke-width": "0.05", "fill": "none", "stroke":"#000070", "stroke-linecap": "round", "stroke-dasharray": "5,2", "points": "1,15 99,15"});
+        // twenty line
+        appendSVGElement(svg, "polyline", {"stroke-width": "0.05", "fill": "none", "stroke":"#000080", "stroke-linecap": "round", "stroke-dasharray": "5,2", "points": "1,5 99,5"});
+
+        target_polyline = appendSVGElement(svg, "polyline", {"stroke-width": "1", "fill": "none", "stroke": "#007900", "points": target_points_str});
+        temperature_polyline = appendSVGElement(svg, "polyline", {"stroke-width": "1", "fill": "none", "stroke": "#0079d9", "points": temperature_points_str});
+
+        document.getElementById("graph").replaceChildren(graph);
+      }
+    })
+    await sleep(10000);
+  }
+}
+
diff --git a/src/static/styles.css b/src/static/styles.css
index 07053ac..f9da5c7 100644
--- a/src/static/styles.css
+++ b/src/static/styles.css
@@ -20,6 +20,14 @@ p.intro {
   padding: 0.2em;
   margin: 0.3em 10vw 0.3em 10vw;
 }
+p#graph {
+    border: 1px solid #B15C1B;
+    padding: 0.2em;
+    margin: 0.3em 15vw 0.3em 15vw;
+    height: 40vw;
+    line-height: 100%;
+    text-align: center;
+}
 p#latest {
     border: 1px solid #B15C1B;
     padding: 0.2em;