Add the no sensors test.

ch-13/2-fusing-sensors/no_imu/no_sensors.py

@@ -0,0 +1,83 @@
+import time
+import json
+
+from adafruit_esp32spi import adafruit_esp32spi_wsgiserver
+from adafruit_wsgi.wsgi_app import WSGIApp
+
+import robot_wifi
+import random
+
+
+class RandomWalkSensors:
+    def __init__(self):
+        self.wifi = None
+        self.server = None
+        self.last_value = 0
+
+        self.start_time = time.monotonic()
+        self.last_time = self.start_time
+
+    def setup_wifi(self, app):
+        print("Setting up wifi.")
+        self.wifi, esp = robot_wifi.connect_to_wifi()
+        self.server = adafruit_esp32spi_wsgiserver.WSGIServer(80, application=app)
+        adafruit_esp32spi_wsgiserver.set_interface(esp)
+        print("Starting server")
+
+        self.server.start()
+        ip_int = ".".join(str(int(n)) for n in esp.ip_address)
+        print(f"IP Address is {ip_int}")
+
+    def data(self, request):
+
+        return (
+            200,
+            [("Content-Type", "application/json")],
+            [
+                json.dumps(
+                    {
+                        "value": self.last_value,
+                        "time": self.last_time - self.start_time,
+                    }
+                )
+            ],
+        )
+
+    def index(self, request):
+        # serve the live graph
+        with open("graphing.html") as fd:
+            return 200, [("Content-Type", "text/html")], [fd.read()]
+            
+    def update(self):
+        # calculate time delta
+        new_time = time.monotonic()
+        time_delta = new_time - self.last_time
+        self.last_time = new_time
+
+        self.last_value += random.randint(-100, 100) * 0.01 * time_delta
+        if self.last_value > 1:
+            self.last_value = 1
+        if self.last_value < -1:
+            self.last_value = -1
+
+    def main_loop(self):
+        while True:
+            try:
+                self.update()
+                self.server.update_poll()
+            except RuntimeError as e:
+                print(f"Server poll error: {type(e)}, {e}")
+                print(f"Resetting ESP...")
+                self.wifi.reset()
+                print("Reset complete.")
+
+    def start(self):
+        app = WSGIApp()
+        app.route("/")(self.index)
+        app.route("/data")(self.data)
+        print("Starting")
+        self.setup_wifi(app)
+        self.main_loop()
+
+
+RandomWalkSensors().start()