Initial commit

main.py

+from machine import UART, Pin
+from servo import Servo
+import time
+
+uart = machine.UART(0, baudrate=9600, bits=8, parity=None, stop=1, tx=machine.Pin(0), rx=machine.Pin(1))
+sg90_servo = Servo(pin=12)
+is_new_gate = False
+
+sg90_servo.move(90)
+
+def next_char():
+    while True:
+        #if uart.any():
+        data = uart.read(1)
+        if data:
+            try:
+                c = data.decode('utf-8')
+                return c
+            except UnicodeError as e:
+                print(e)
+
+while True:
+    char = next_char()
+    print("char = ", char)
+    if char == '?':
+        continue
+    deg = -1.0
+    if 'a' <= char <= 'z':
+        deg = (ord(char) - ord('a')) / 25 * 180
+    if 'A' <= char <= 'Z':
+        deg = (ord(char) - ord('A')) / 25 * 180
+    #assert abs(deg + 1) > 0.0001
+    #sg90_servo.move(deg)
+    if abs(deg + 1) > 0.0001:
+        sg90_servo.move(deg)
+
+
+

servo.py

+from machine import Pin, PWM
+
+class Servo:
+    __servo_pwm_freq = 50
+    __min_u16_duty = 1640 - 2 # offset for correction
+    __max_u16_duty = 7864 - 0  # offset for correction
+    min_angle = 0
+    max_angle = 180
+    current_angle = 0.001
+
+
+    def __init__(self, pin):
+        self.__initialise(pin)
+
+
+    def update_settings(self, servo_pwm_freq, min_u16_duty, max_u16_duty, min_angle, max_angle, pin):
+        self.__servo_pwm_freq = servo_pwm_freq
+        self.__min_u16_duty = min_u16_duty
+        self.__max_u16_duty = max_u16_duty
+        self.min_angle = min_angle
+        self.max_angle = max_angle
+        self.__initialise(pin)
+
+
+    def move(self, angle):
+        # round to 2 decimal places, so we have a chance of reducing unwanted servo adjustments
+        angle = round(angle, 2)
+        # do we need to move?
+        if angle == self.current_angle:
+            return
+        self.current_angle = angle
+        # calculate the new duty cycle and move the motor
+        duty_u16 = self.__angle_to_u16_duty(angle)
+        self.__motor.duty_u16(duty_u16)
+
+    def __angle_to_u16_duty(self, angle):
+        return int((angle - self.min_angle) * self.__angle_conversion_factor) + self.__min_u16_duty
+
+
+    def __initialise(self, pin):
+        self.current_angle = -0.001
+        self.__angle_conversion_factor = (self.__max_u16_duty - self.__min_u16_duty) / (self.max_angle - self.min_angle)
+        self.__motor = PWM(Pin(pin))
+        self.__motor.freq(self.__servo_pwm_freq)
+