Chapter 11 and 13 - wifi code (pre bluetooth)

ch-11/1-encoder-speed/encoder_speed.py

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+import time
+import json
+
+from adafruit_esp32spi import adafruit_esp32spi_wsgiserver
+from adafruit_wsgi.wsgi_app import WSGIApp
+
+import robot
+import robot_wifi
+
+
+class SpeedCountApp:
+    def __init__(self):
+        self.intended_speed = 0.9
+        self.last_time = time.monotonic()
+        self.wifi = None
+        self.server = None
+
+    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 index(self, request):
+        new_time = time.monotonic()
+        time_delta = new_time - self.last_time
+        self.last_time = new_time
+
+        left_speed = robot.left_encoder.get_speed(time_delta)
+        right_speed = robot.right_encoder.get_speed(time_delta)
+        return (
+            200,
+            [("Content-Type", "application/json")],
+            [
+                json.dumps(
+                    {
+                        "left_speed": left_speed,
+                        "right_speed": right_speed,
+                        "time": self.last_time,
+                    }
+                )
+            ],
+        )
+
+    def main_loop(self):
+        robot.set_left(self.intended_speed)
+        robot.set_right(self.intended_speed)
+        while True:
+            try:
+                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)
+        print("Starting")
+        try:
+            self.setup_wifi(app)
+            self.main_loop()
+        finally:
+            robot.stop()
+
+
+SpeedCountApp().start()

ch-11/1-encoder-speed/pio_encoder.py

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+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-11/1-encoder-speed/robot.py

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+import board
+import pwmio
+import pio_encoder
+import busio
+import adafruit_vl53l1x
+
+
+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)
+
+left_distance = adafruit_vl53l1x.VL53L1X(i2c0)
+right_distance = adafruit_vl53l1x.VL53L1X(i2c1)
+
+
+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-11/1-encoder-speed/robot_wifi.py

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+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

ch-11/2-straight-line-speed/pid.py

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+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-11/2-straight-line-speed/pio_encoder.py

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+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-11/2-straight-line-speed/robot.py

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+import board
+import pwmio
+import pio_encoder
+import busio
+import adafruit_vl53l1x
+
+
+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)
+
+left_distance = adafruit_vl53l1x.VL53L1X(i2c0)
+right_distance = adafruit_vl53l1x.VL53L1X(i2c1)
+
+
+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-11/2-straight-line-speed/robot_wifi.py

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+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

ch-11/2-straight-line-speed/speed_control.py

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+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 SpeedControlApp:
+    def __init__(self):
+        self.wifi = None
+        self.server = None
+
+        self.intended_speed = 0.9
+        self.last_time = time.monotonic()
+        self.speed_to_encoder_factor = 1/5100
+
+        self.left_speed_pid = pid.PID(0, -0.7, 0, self.intended_speed)
+        self.right_speed_pid = pid.PID(0, -0.7, 0, self.intended_speed)
+        self.left_pid_output = 0
+        self.right_pid_output = 0
+        self.left_speed = 0
+        self.right_speed = 0
+
+
+    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 update(self):
+        new_time = time.monotonic()
+        time_delta = new_time - self.last_time
+        self.last_time = new_time
+
+        self.left_speed = robot.left_encoder.get_speed(time_delta) * self.speed_to_encoder_factor
+        self.right_speed = robot.right_encoder.get_speed(time_delta) * self.speed_to_encoder_factor
+
+        self.left_pid_output = self.left_speed_pid.update(self.left_speed, time_delta)
+        self.right_pid_output = self.right_speed_pid.update(self.right_speed, time_delta)
+
+        # print({
+        #         "left_speed": self.left_speed,
+        #         "left_pid": self.left_pid_output,
+        #         "right_speed": self.right_speed,
+        #         "right_pid": self.right_pid_output,
+        #         "time": self.last_time,
+        #         "error_sum": self.left_speed_pid.error_sum
+        #     })
+
+        # robot.set_left(self.left_pid_output)
+        # robot.set_right(self.right_pid_output)
+
+    def movement_generator(self):
+        while True:
+            self.update()
+            data = json.dumps(
+                    {
+                        "left_speed": self.left_speed,
+                        "left_pid": self.left_pid_output,
+                        "right_speed": self.right_speed,
+                        "right_pid": self.right_pid_output,
+                        "time": self.last_time,
+                    }
+                ) + "/n"
+            print(data)
+            yield data
+
+    def index(self, request):
+        return (
+            200,
+            [("Content-Type", "application/json")],
+            self.movement_generator(),
+        )
+
+    def main_loop(self):
+        while True:
+            try:
+                self.update()
+
+                # time.sleep(0.1)
+                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)
+        print("Starting")
+        try:
+            self.setup_wifi(app)
+            self.main_loop()
+        finally:
+            robot.stop()
+
+
+SpeedControlApp().start()