micropython esp32 低成本气压式高度计制作教程（代码与接线部分）

低成本气压式高度计制作教程（代码与接线部分）

bmp.py

from micropython import const
from machine import I2C
BMP280_I2C_ADDR = const(0x76)
class BMP280():
    def __init__(self, i2c):
        self.i2c = i2c
        self.tb = bytearray(1)
        self.rb = bytearray(1)
        self.dig_T1 = self.get2Reg(0x88)
        self.dig_T2 = self.short(self.get2Reg(0x8A))
        self.dig_T3 = self.short(self.get2Reg(0x8C))
        self.dig_P1 = self.get2Reg(0x8E)
        self.dig_P2 = self.short(self.get2Reg(0x90))
        self.dig_P3 = self.short(self.get2Reg(0x92))
        self.dig_P4 = self.short(self.get2Reg(0x94))
        self.dig_P5 = self.short(self.get2Reg(0x96))
        self.dig_P6 = self.short(self.get2Reg(0x98))
        self.dig_P7 = self.short(self.get2Reg(0x9A))
        self.dig_P8 = self.short(self.get2Reg(0x9C))
        self.dig_P9 = self.short(self.get2Reg(0x9E))
        self.mode = 3
        self.osrs_p = 3
        self.osrs_t = 1
        self.setReg(0xF4, 0x2F)
        self.setReg(0xF5, 0x0C)
        self.filter = 3
        self.T = 0
        self.P = 0
        self.version = '1.0'
    def short(self, dat):
        if dat > 32767:
            return dat - 65536
        else:
            return dat
    # set reg
    def setReg(self, reg, dat):
        self.tb[0] = dat
        self.i2c.writeto_mem(BMP280_I2C_ADDR, reg, self.tb)
    # get reg
    def getReg(self, reg):
        self.i2c.readfrom_mem_into(BMP280_I2C_ADDR, reg, self.rb)
        return self.rb[0]
    # get two reg
    def get2Reg(self, reg):
        return self.getReg(reg) + self.getReg(reg+1) * 256
    def get(self):
        adc_T = (self.getReg(0xFA)<<12) + (self.getReg(0xFB)<>4)
        var1 = (((adc_T>>3)-(self.dig_T1<>11
        var2 = (((((adc_T>>4)-self.dig_T1)*((adc_T>>4) - self.dig_T1))>>12)*self.dig_T3)>>14
        t = var1+var2
        self.T = ((t * 5 + 128) >> 8)/100
        var1 = (t>>1) - 64000
        var2 = (((var1>>2) * (var1>>2)) >> 11 ) * self.dig_P6
        var2 = var2 + ((var1*self.dig_P5)<>2)+(self.dig_P4<>2)*(var1>>2))>>13)>>3) + (((self.dig_P2) * var1)>>1))>>18
        var1 = ((32768+var1)*self.dig_P1)>>15
        if var1 == 0:
            return  # avoid exception caused by division by zero
        adc_P = (self.getReg(0xF7)<<12) + (self.getReg(0xF8)<>4)
        p=((1048576-adc_P)-(var2>>12))*3125
        if p < 0x80000000:
            p = (p << 1) // var1
        else:
            p = (p // var1) * 2
        var1 = (self.dig_P9 * (((p>>3)*(p>>3))>>13))>>12
        var2 = (((p>>2)) * self.dig_P8)>>13
        self.P = p + ((var1 + var2 + self.dig_P7) >> 4)
        return [self.T, self.P]
    # get Temperature in Celsius
    def getTemp(self):
        self.get()
        return self.T
    # get Pressure in Pa
    def getPress(self):
        self.get()
        return self.P
    # Calculating absolute altitude
    def getAltitude(self):
        return 44330*(1-(self.getPress()/101325)**(1/5.255))
    # sleep mode
    def poweroff(self):
        self.setReg(0xF4, 0)
    # normal mode
    def poweron(self):
        self.setReg(0xF4, 0x2F)

main.py

import time
from machine import Pin,I2C
import _thread
import bmp280

def run():
    i2c = I2C(sda=Pin(6), scl=Pin(7))
    b = bmp280.BMP280(i2c)
    da = 0
    t=0
    try:
        while(1):
            da=da+1
            f = open("date"+str(da)+".txt",'r')
            f.close()
    except:
        f = open("date"+str(da)+".txt",'a')
        f.write('气压计数据记录\n')
        f.write("记录时间:  原始温度和气压:  高度:\n")
        f.close()
    while(True):
        time.sleep_ms(100)
        f = open("date"+str(da)+".txt",'a')
        t=t+1
        y = b.get()
        p = b.getPress()
        h = (101325-p)*9/100
        dat = (str(t/10)+"  "+str(y)+"  "+str(h)+"\n")
        f.write(dat)
        #print(h)
        f.close()
pboot = Pin(9,Pin.IN)

def bled():
    led4 = Pin(12,Pin.OUT)
    led5 = Pin(13,Pin.OUT)
    while(True):
        led4.on()
        time.sleep_ms(500)
        led4.off()
        led5.on()
        time.sleep_ms(500)
        led5.off()
        #_thread.start_new_thread(bled,())
while(1):
    time.sleep_ms(100)
    if(pboot.value()==0):
        _thread.start_new_thread(bled,())
        run()
        break

接线：