Pico W tilt controller: MPU6050 points a servo

# Somatosensory controller: tip the MPU6050 (I2C1, GP6 and GP7) and the
# servo on GP15 follows. The tilt comes from gravity: atan2 of the y and
# z accelerations, averaged over a few readings to steady it.
from machine import I2C, Pin, PWM
from mpu6050 import MPU6050
import math
import time

mpu = MPU6050(I2C(1, sda=Pin(6), scl=Pin(7), freq=400000))
servo = PWM(Pin(15))
servo.freq(50)

def angle(deg):
    deg = min(max(deg, 0), 180)
    servo.duty_u16((500 + int(deg) * 2000 // 180) * 65535 // 20000)

while True:
    total = 0
    for _ in range(10):
        ax, ay, az = mpu.accel()
        total += math.degrees(math.atan2(ax, az))
        time.sleep_ms(5)
    tilt = total / 10
    angle(90 + tilt)
    print("tilt %.0f, servo %.0f" % (tilt, 90 + tilt))
    time.sleep_ms(50)

# mpu6050.py: read an MPU6050's accelerometer and gyroscope over I2C.
# At power-up the chip is asleep; writing 0 to register 0x6B wakes it.
# The default ranges are +-2 g (16384 counts a g) and +-250 degrees a
# second (131 counts a degree a second).
import struct

class MPU6050:
    def __init__(self, i2c, addr=0x68):
        self.i2c = i2c
        self.addr = addr
        i2c.writeto_mem(addr, 0x6B, bytes([0]))

    def raw(self):
        data = self.i2c.readfrom_mem(self.addr, 0x3B, 14)
        return struct.unpack(">hhhhhhh", data)   # ax ay az temp gx gy gz

    def accel(self):
        ax, ay, az = self.raw()[0:3]
        return ax / 16384, ay / 16384, az / 16384

    def gyro(self):
        gx, gy, gz = self.raw()[4:7]
        return gx / 131, gy / 131, gz / 131