Add a power graph.

meshview/templates/node.html

@@ -39,6 +39,7 @@
                             <dt>hw model</dt>
                             <dd>{{node.hw_model}}</dd>
                         </dl>
+                        <a href="/graph/power/{{node_id}}"><img src="/graph/power/{{node_id}}" height="200em" width="200em"/></a>
                     </div>
                     {% else %}
                     <div class="card-body">
@@ -50,7 +51,6 @@
             <div class="col mb-3">
                 <div id="map"/>
             </div>
-
         </div>
 
         <div class="row">

meshview/web.py

@@ -1,4 +1,5 @@
 import asyncio
+import io
 
 from dataclasses import dataclass
 import datetime
@@ -6,6 +7,8 @@ from aiohttp_sse import sse_response
 import ssl
 import re
 
+import seaborn as sns
+import matplotlib.pyplot as plt
 from aiohttp import web
 from markupsafe import Markup
 from jinja2 import Environment, PackageLoader, select_autoescape
@@ -400,6 +403,37 @@ async def packet(request):
     )
 
 
+@routes.get("/graph/power/{node_id}")
+async def graph_power(request):
+    date = []
+    battery = []
+    voltage = []
+    for p in await store.get_packets_from(int(request.match_info['node_id']), PortNum.TELEMETRY_APP):
+        _, payload = decode_payload.decode(p)
+        if not payload.HasField('device_metrics'):
+            continue
+        date.append(datetime.datetime.fromtimestamp(payload.time))
+        battery.append(payload.device_metrics.battery_level)
+        voltage.append(payload.device_metrics.voltage)
+
+    fig, ax1 = plt.subplots(figsize=(10, 10))
+    ax1.set_xlabel('time')
+    ax1.set_ylabel('battery level', color='tab:blue')
+    ax2 = ax1.twinx()
+    ax2.set_ylabel('voltage', color='tab:red')
+    sns.lineplot(x=date, y=battery, ax=ax1, color='tab:blue')
+    sns.lineplot(x=date, y=voltage, ax=ax2, color='tab:red')
+
+    png = io.BytesIO()
+    plt.savefig(png, dpi=100)
+
+    return web.Response(
+        body=png.getvalue(),
+        content_type="image/png",
+    )
+
+
+
 async def run_server(bind, port, tls_cert):
     app = web.Application()
     app.add_routes(routes)

requirements.txt

@@ -8,3 +8,4 @@ aiodns
 Jinja2
 aiohttp-sse
 asyncpg
+seaborn