Park the full test so Leo can try this out.

ch-13/2-fusing-sensors/all_sensors_test/all_sensors_test.py

@@ -0,0 +1,121 @@
+import time
+import json
+
+from adafruit_esp32spi import adafruit_esp32spi_wsgiserver
+from adafruit_wsgi.wsgi_app import WSGIApp
+
+import robot
+import robot_wifi
+import pid
+
+
+class FollowObject:
+    def __init__(self):
+        self.max_speed = 0.7
+        self.follow_pid = pid.PID(0.1, 0.1, 0.015, 15)
+        self.wifi = None
+        self.server = None
+
+        self.last_time = time.monotonic()
+        self.left_dist = 0
+        self.right_dist = 0
+        self.pid_output = 0
+        self.left_speed = 0
+        self.right_speed = 0
+
+    def setup_robot(self):
+        robot.left_distance.distance_mode = 1
+
+    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):
+        imu_data = robot.imu.euler
+
+        return (
+            200,
+            [("Content-Type", "application/json")],
+            [
+                json.dumps(
+                    {
+                        "last_value": self.follow_pid.last_value,
+                        "pid_output": self.pid_output,
+                        "imu_z": imu_data[2],
+                        "left_speed": self.left_speed,
+                        "right_speed": self.right_speed,
+                        "left_distance": self.left_dist,
+                        "right_distance": self.right_dist,
+                        "time": self.last_time,
+                    }
+                )
+            ],
+        )
+
+    def index(self, request):
+        # serve the live graph
+        with open("graphing.html") as fd:
+            return 200, [("Content-Type", "text/html")], [fd.read()]
+            
+    def movement_update(self):
+        # do we have data
+        if robot.left_distance.data_ready:
+            self.left_dist = robot.left_distance.distance
+            self.right_dist = robot.right_distance.distance
+
+            # calculate time delta
+            new_time = time.monotonic()
+            time_delta = new_time - self.last_time
+            self.last_time = new_time
+
+            # get speeds from pid
+            self.pid_output = self.follow_pid.update(self.left_dist, time_delta)
+            speed = self.pid_output * self.max_speed
+
+            self.left_speed = robot.left_encoder.get_speed(time_delta)
+            self.right_speed = robot.right_encoder.get_speed(time_delta)
+
+            # make movements
+            robot.set_left(speed)
+            robot.set_right(speed)
+
+            # reset and loop
+            robot.left_distance.clear_interrupt()
+            robot.right_distance.clear_interrupt()
+
+    def main_loop(self):
+        robot.left_distance.start_ranging()
+        while True:
+            try:
+                self.movement_update()
+                self.server.update_poll()
+            except RuntimeError as e:
+                print(f"Server poll error: {type(e)}, {e}")
+                robot.stop()
+                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")
+        try:
+            self.setup_robot()
+            self.setup_wifi(app)
+            self.main_loop()
+        finally:
+            robot.stop()
+            robot.left_distance.clear_interrupt()
+            robot.left_distance.stop_ranging()
+
+
+FollowObject().start()

ch-13/2-fusing-sensors/all_sensors_test/code.py

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+import all_sensors_test

ch-13/2-fusing-sensors/all_sensors_test/graphing.html

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+<!DOCTYPE html>
+<b>Dist</b>
+<div id="dist"><svg></svg></div>
+<b>Speed</b>
+<div id="speed"><svg></svg></div>
+<b>Imu</b>
+<div id="imu"><svg></svg></div>
+
+<script type="module">
+  import * as d3_module from "https://cdn.jsdelivr.net/npm/d3@7";
+  import * as Plot from "https://cdn.skypack.dev/@observablehq/plot@0.4";
+
+  var current_dataset = [];
+  while (true) {
+    // fetch new data
+    await d3.json("/data").then(function(data) {
+      // then append to list
+      current_dataset.push(data);
+      // Map to a 10s (n S) sliding window
+      // ie find the most recent value, then reduce/filter anything more than 10s earlier than that.
+      const most_recent_time = current_dataset[current_dataset.length - 1].time;
+      const window_start = Math.max(0, most_recent_time - 10);
+      // filter the list
+      current_dataset = current_dataset.filter(
+        value => value.time >= window_start
+      );
+      // render dist graph
+      var dist_graph = Plot.plot({
+        x: { grid: true},
+        y: { grid: true},
+        marks: [
+          Plot.line(current_dataset, {x: "time", y: "left_distance", stroke: "red"}),
+          Plot.line(current_dataset, {x: "time", y: "right_distance", stroke: "blue"}),
+        ]
+      });
+      var graphNode = document.getElementById("dist");
+      graphNode.replaceChild(dist_graph, graphNode.firstChild);
+      // render speed graph
+      var speed_graph = Plot.plot({
+        x: { grid: true},
+        y: { grid: true},
+        marks: [
+          Plot.line(current_dataset, {x: "time", y: "left_speed", stroke: "red"}),
+          Plot.line(current_dataset, {x: "time", y: "right_speed", stroke: "blue"}),
+        ]
+      });
+      var graphNode = document.getElementById("speed");
+      graphNode.replaceChild(speed_graph, graphNode.firstChild);
+      // render imu graph
+      var speed_graph = Plot.plot({
+        x: { grid: true},
+        y: { grid: true},
+        marks: [
+          Plot.line(current_dataset, {x: "time", y: "imu_z", stroke: "red"}),
+        ]
+      });
+      var graphNode = document.getElementById("imu");
+      graphNode.replaceChild(speed_graph, graphNode.firstChild);        
+    });
+  }
+  // }
+</script>

ch-13/2-fusing-sensors/all_sensors_test/pid.py

@@ -0,0 +1,39 @@
+class PID:
+    def __init__(self, proportional_k, integral_k, differential_k, set_point):
+        self.proportional_k = proportional_k
+        self.integral_k = integral_k
+        self.differential_k = differential_k
+        self.set_point = set_point
+
+        self.error_sum = 0
+        self.last_value = 0
+        self.min_output = -1
+        self.max_output = 1
+
+        self.dead_zone = 0.3
+
+    def update(self, measurement, time_delta):
+        error_value = measurement - self.set_point
+        proportional = error_value * self.proportional_k
+
+        # calculate integral
+        self.error_sum += error_value * time_delta
+        # clamp it
+        self.error_sum = min(self.max_output, self.error_sum)
+        self.error_sum = max(self.min_output, self.error_sum)
+
+        integral = self.error_sum * self.integral_k
+
+        differentiated_error = (error_value - self.last_value) / time_delta
+        differential = differentiated_error * self.differential_k
+        self.last_value = error_value
+
+        output = proportional + integral + differential
+        # clamp output
+        if abs(output) < self.dead_zone:
+            output = 0
+        else:
+            output = min(self.max_output, output)
+            output = max(self.min_output, output)
+
+        return output

ch-13/2-fusing-sensors/all_sensors_test/pio_encoder.py

@@ -0,0 +1,84 @@
+import rp2pio
+import adafruit_pioasm
+import array
+
+program = """
+; use the osr for count
+; input pins c1 c2
+
+    set y, 0            ; clear y
+    mov osr, y          ; and clear osr
+read:
+    ; x will be the old value
+    ; y the new values
+    mov x, y            ; store old Y in x
+    in null, 32         ; Clear ISR - using y
+    in pins, 2          ; read two pins into y
+    mov y, isr
+    jmp x!=y, different ; Jump if its different
+    jmp read            ; otherwise loop back to read
+
+different:
+    ; x has old value, y has new.
+    ; extract the upper bit of X.
+    in x, 31             ; get bit 31 - old p1 (remember which direction it came in)
+    in null, 31         ; keep only 1 bit
+    mov x, isr          ; put this back in x
+    jmp !x, c1_old_zero
+
+c1_old_not_zero:
+    jmp pin, count_up
+    jmp count_down
+
+c1_old_zero:
+    jmp pin, count_down
+    ; fall through
+count_up:
+    ; for a clockwise move - we'll add 1 by inverting
+    mov x, ~ osr        ; store inverted OSR on x
+    jmp x--, fake       ; use jump to take off 1
+fake:
+    mov x, ~ x          ; invert back
+    jmp send
+count_down:
+    ; for a clockwise move, just take one off
+    mov x, osr          ; store osr in x
+    jmp x--, send       ; dec and send
+send:
+    ; send x.
+    mov isr, x          ; send it
+    push noblock        ; put ISR into input FIFO
+    mov osr, x          ; put X back in OSR
+    jmp read            ; loop back
+"""
+
+assembled = adafruit_pioasm.assemble(program)
+
+
+class QuadratureEncoder:
+    def __init__(self, first_pin, second_pin, reversed=False):
+        """Encoder with 2 pins. Must use sequential pins on the board"""
+        self.sm = rp2pio.StateMachine(
+            assembled,
+            frequency=0,
+            first_in_pin=first_pin,
+            jmp_pin=second_pin,
+            in_pin_count=2,
+        )
+        self.reversed = reversed
+        self._buffer = array.array("i", [0])
+        self.previous_reading = 0
+
+    def read(self):
+        while self.sm.in_waiting:
+            self.sm.readinto(self._buffer)
+        if self.reversed:
+            return -self._buffer[0]
+        else:
+            return self._buffer[0]
+
+    def get_speed(self, delta_time):
+        new_read = self.read()
+        distance = new_read - self.previous_reading
+        self.previous_reading = new_read
+        return distance / delta_time

ch-13/2-fusing-sensors/all_sensors_test/robot.py

@@ -0,0 +1,54 @@
+import board
+import pwmio
+import pio_encoder
+import busio
+import adafruit_vl53l1x
+import adafruit_bno055
+
+
+motor_A1 = pwmio.PWMOut(board.GP17)
+motor_A2 = pwmio.PWMOut(board.GP16)
+motor_B1 = pwmio.PWMOut(board.GP18)
+motor_B2 = pwmio.PWMOut(board.GP19)
+
+right_motor = motor_A1, motor_A2
+left_motor = motor_B1, motor_B2
+
+right_encoder = pio_encoder.QuadratureEncoder(board.GP20, board.GP21, reversed=True)
+left_encoder = pio_encoder.QuadratureEncoder(board.GP26, board.GP27)
+
+i2c0 = busio.I2C(sda=board.GP0, scl=board.GP1)
+i2c1 = busio.I2C(sda=board.GP2, scl=board.GP3)
+
+right_distance = adafruit_vl53l1x.VL53L1X(i2c0)
+left_distance = adafruit_vl53l1x.VL53L1X(i2c1)
+
+imu = adafruit_bno055.BNO055_I2C(i2c0)
+
+def stop():
+    motor_A1.duty_cycle = 0
+    motor_A2.duty_cycle = 0
+    motor_B1.duty_cycle = 0
+    motor_B2.duty_cycle = 0
+
+
+def set_speed(motor, speed):
+    # Swap motor pins if we reverse the speed
+    if speed < 0:
+        direction = motor[1], motor[0]
+        speed = -speed
+    else:
+        direction = motor
+    speed = min(speed, 1)  # limit to 1.0
+    max_speed = 2 ** 16 - 1
+
+    direction[0].duty_cycle = int(max_speed * speed)
+    direction[1].duty_cycle = 0
+
+
+def set_left(speed):
+    set_speed(left_motor, speed)
+
+
+def set_right(speed):
+    set_speed(right_motor, speed)

ch-13/2-fusing-sensors/all_sensors_test/robot_wifi.py

@@ -0,0 +1,25 @@
+import board
+import busio
+from digitalio import DigitalInOut
+from adafruit_esp32spi import adafruit_esp32spi
+from adafruit_esp32spi import adafruit_esp32spi_wifimanager
+
+try:
+    from secrets import secrets
+except ImportError:
+    print("WiFi secrets are kept in secrets.py, please add them there!")
+    raise
+
+
+def connect_to_wifi():
+    esp32_cs = DigitalInOut(board.GP10)
+    esp32_ready = DigitalInOut(board.GP9)
+    esp32_reset = DigitalInOut(board.GP8)
+
+    spi = busio.SPI(board.GP14, MOSI=board.GP11, MISO=board.GP12)
+    esp = adafruit_esp32spi.ESP_SPIcontrol(spi, esp32_cs, esp32_ready, esp32_reset)
+    esp.reset()
+    wifi = adafruit_esp32spi_wifimanager.ESPSPI_WiFiManager(esp, secrets)
+    wifi.connect()
+
+    return wifi, esp