'''
Baseado na biblioteca de:
https://github.com/bogde/HX711
'''
from machine import Pin
import time
from utime import sleep

class HX711:
    def __init__(self, dout, pd_sck, gain=128):
        self.PD_SCK = Pin(pd_sck, Pin.OUT)
        self.DOUT = Pin(dout, Pin.IN, Pin.PULL_UP)
        self.GAIN = 0
        self.set_gain(gain)

    def set_gain(self, gain):
        if gain == 128:
            self.GAIN = 1
        elif gain == 64:
            self.GAIN = 3
        elif gain == 32:
            self.GAIN = 2
        self.read()

    def is_ready(self):
        return self.DOUT.value() == 0

    def read(self):
        while not self.is_ready():
            pass

        data = [0x00] * 3
        for j in range(3):
            for i in range(8):
                self.PD_SCK.value(1)
                data[j] <<= 1
                self.PD_SCK.value(0)
                if self.DOUT.value():
                    data[j] |= 0x01

        for i in range(self.GAIN):
            self.PD_SCK.value(1)
            self.PD_SCK.value(0)

        value = data[0] << 16 | data[1] << 8 | data[2]

        if value & 0x800000:
            value |= ~0xffffff

        return value

    def read_average(self, times=3):
        sum = 0
        for _ in range(times):
            sum += self.read()
        return sum / times

    def get_value(self, times=3):
        return self.read_average(times)

    def get_units(self, times=3):
        return self.get_value(times)

    def tare(self, times=15):
        sum = self.read_average(times)
        self.set_offset(sum)

    def set_offset(self, offset):
        self.OFFSET = offset

    def set_scale(self, scale):
        self.SCALE = scale

    def power_down(self):
        self.PD_SCK.value(0)
        self.PD_SCK.value(1)

    def power_up(self):
        self.PD_SCK.value(0)

# Exemplo de uso
hx = HX711(dout=21, pd_sck=22)
hx.set_scale(2280)
hx.tare()
while (True):
    
    print("Peso: ", hx.get_units(), "g")
    sleep(2)