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RaspberryPiでBME280を使って20x4 LCDに表示する * 準備 [#maac11d6] - raspi-configでI2Cを有効にする - Pythonにライブラリを追加する~ $ sudo pip install subus2~ $ sudo pip install Adafruit_CharLCD * LCDの接続（LCDは3.3V用を使う） [#i4108e5a] lcd_d0= n.c~ lcd_d1= n.c~ lcd_d2= n.c~ lcd_d3= n.c~ lcd_d4= GP-5（29ピン）~ lcd_d5= GP-6（31ピン）~ lcd_d6= GP-13（33ピン）~ lcd_d7= GP-19（35ピン）~ lcd_rs= GP-20（38ピン）~ lcd_en= GP-21（40ピン）~ lcd_rw= GND~ lcd_d0= n.c~ lcd_d1= n.c~ lcd_d2= n.c~ lcd_d3= n.c~ LCDのR/WピンをLow固定にして書き込み固定モードであれば、5V電源LCDを3.3V信号で駆動することも可能。~ パラレルではなくI2Cの場合は双方向になるので無理。~ * MBE280の接続~ [#ia675285] BME_SDA= 3ピン~ BME_SCL= 5ピン * VCC/GNDの接続 [#hac0fe3e] VCC= 1ピン（3.3V）~ GND= 6ピン * ソースコード [#x0148071] pi@pi3b2:~/bme280$ cat bme280_lcd.py #coding: utf-8 from smbus2 import SMBus import time import Adafruit_CharLCD as LCD from datetime import datetime import os import commands bus_number = 1 i2c_address = 0x77 bus = SMBus(bus_number) digT = [] digP = [] digH = [] t_fine = 0.0 # GND Pin: 6 9 14 30 25 30 34 39 # LCD pin assign(GPIO Num) lcd_rs= 20 # 38pin lcd_en= 21 # 40pin lcd_d4= 5 # 29pin lcd_d5= 6 # 31pin lcd_d6= 13 # 33pin lcd_d7= 19 # 35pin lcd_backlight = 4 # Define LCD column and row size. lcd_columns= 20 lcd_rows= 4 # Initialize the LCD using the pins above. lcd = LCD.Adafruit_CharLCD(lcd_rs, lcd_en, lcd_d4, lcd_d5, lcd_d6, lcd_d7,lcd_columns, lcd_rows, lcd_backlight) lcd.clear() def writeReg(reg_address, data): bus.write_byte_data(i2c_address,reg_address,data) def get_calib_param(): calib = [] for i in range (0x88,0x88+24): calib.append(bus.read_byte_data(i2c_address,i)) calib.append(bus.read_byte_data(i2c_address,0xA1)) for i in range (0xE1,0xE1+7): calib.append(bus.read_byte_data(i2c_address,i)) digT.append((calib[1] << 8) | calib[0]) digT.append((calib[3] << 8) | calib[2]) digT.append((calib[5] << 8) | calib[4]) digP.append((calib[7] << 8) | calib[6]) digP.append((calib[9] << 8) | calib[8]) digP.append((calib[11]<< 8) | calib[10]) digP.append((calib[13]<< 8) | calib[12]) digP.append((calib[15]<< 8) | calib[14]) digP.append((calib[17]<< 8) | calib[16]) digP.append((calib[19]<< 8) | calib[18]) digP.append((calib[21]<< 8) | calib[20]) digP.append((calib[23]<< 8) | calib[22]) digH.append( calib[24] ) digH.append((calib[26]<< 8) | calib[25]) digH.append( calib[27] ) digH.append((calib[28]<< 4) | (0x0F & calib[29])) digH.append((calib[30]<< 4) | ((calib[29] >> 4) & 0x0F)) digH.append( calib[31] ) for i in range(1,2): if digT[i] & 0x8000: digT[i] = (-digT[i] ^ 0xFFFF) + 1 for i in range(1,8): if digP[i] & 0x8000: digP[i] = (-digP[i] ^ 0xFFFF) + 1 for i in range(0,6): if digH[i] & 0x8000: digH[i] = (-digH[i] ^ 0xFFFF) + 1 def readData(): data = [] for i in range (0xF7, 0xF7+8): data.append(bus.read_byte_data(i2c_address,i)) pres_raw = (data[0] << 12) | (data[1] << 4) | (data[2] >> 4) temp_raw = (data[3] << 12) | (data[4] << 4) | (data[5] >> 4) hum_raw = (data[6] << 8) | data[7] compensate_T(temp_raw) compensate_P(pres_raw) compensate_H(hum_raw) def compensate_P(adc_P): global t_fine,p pressure = 0.0 v1 = (t_fine / 2.0) - 64000.0 v2 = (((v1 / 4.0) * (v1 / 4.0)) / 2048) * digP[5] v2 = v2 + ((v1 * digP[4]) * 2.0) v2 = (v2 / 4.0) + (digP[3] * 65536.0) v1 = (((digP[2] * (((v1 / 4.0) * (v1 / 4.0)) / 8192)) / 8) + ((digP[1] * v1) / 2.0)) / 262144 v1 = ((32768 + v1) * digP[0]) / 32768 if v1 == 0: return 0 pressure = ((1048576 - adc_P) - (v2 / 4096)) * 3125 if pressure < 0x80000000: pressure = (pressure * 2.0) / v1 else: pressure = (pressure / v1) * 2 v1 = (digP[8] * (((pressure / 8.0) * (pressure / 8.0)) / 8192.0)) / 4096 v2 = ((pressure / 4.0) * digP[7]) / 8192.0 pressure = pressure + ((v1 + v2 + digP[6]) / 16.0) #print "%7.2f hPa" % (pressure/100) p = "%4.0f" % (pressure/100) def compensate_T(adc_T): global t_fine,t v1 = (adc_T / 16384.0 - digT[0] / 1024.0) * digT[1] v2 = (adc_T / 131072.0 - digT[0] / 8192.0) * (adc_T / 131072.0 - digT[0] / 8192.0) * digT[2] t_fine = v1 + v2 temperature = t_fine / 5120.0 #print " %-6.2f℃" % (temperature) t = "%-4.1f" % (temperature) def compensate_H(adc_H): global t_fine,h var_h = t_fine - 76800.0 if var_h != 0: var_h = (adc_H - (digH[3] * 64.0 + digH[4]/16384.0 * var_h)) * (digH[1] / 65536.0 * (1.0 + digH[5] / 67108864.0 * var_h * (1.0 + digH[2] / 67108864.0 * var_h))) else: return 0 var_h = var_h * (1.0 - digH[0] * var_h / 524288.0) if var_h > 100.0: var_h = 100.0 elif var_h < 0.0: var_h = 0.0 #print " %6.2f ％" % (var_h) h = "%2.0f" % (var_h) def setup(): osrs_t = 1 #Temperature oversampling x 1 osrs_p = 1 #Pressure oversampling x 1 osrs_h = 1 #Humidity oversampling x 1 mode = 3 #Normal mode t_sb = 5 #Tstandby 1000ms filter = 0 #Filter off spi3w_en = 0 #3-wire SPI Disable ctrl_meas_reg = (osrs_t << 5) | (osrs_p << 2) | mode config_reg = (t_sb << 5) | (filter << 2) | spi3w_en ctrl_hum_reg = osrs_h writeReg(0xF2,ctrl_hum_reg) writeReg(0xF4,ctrl_meas_reg) writeReg(0xF5,config_reg) setup() get_calib_param() if __name__ == '__main__': try: time.sleep(1) lcd.clear() while True: readData() cpu_temp = commands.getoutput("vcgencmd measure_temp").split('=') #cpu_volt=commands.getoutput("vcgencmd measure_volts").split('=') cpu_mem=commands.getoutput("vcgencmd get_mem arm").split('=') cpu_gpu=commands.getoutput("vcgencmd get_mem gpu").split('=') dt_now = datetime.now() week_num = dt_now.strftime("%w") if week_num == "0": week_text = 'Sun' if week_num == "1": week_text = 'Mon' if week_num == "2": week_text = 'Tue' if week_num == "3": week_text = 'Wed' if week_num == "4": week_text = 'Thu' if week_num == "5": week_text = 'Fri' if week_num == "6": week_text = 'Sat' lcd.blink(False) #message_text = dt_now.strftime("%Y/%m/%d ") message_text = dt_now.strftime("%m/%d") + "(" + week_text + ") " + dt_now.strftime("%H:%M:%S") lcd.message(message_text) lcd.set_cursor(0,2) message_text = "CPU:" + cpu_temp[1] + " " + cpu_mem[1] + " " + cpu_gpu[1] lcd.message(message_text) lcd.set_cursor(0,3) message_text = "Ext:" + p + "hP " + t + "C " + h + "%" + "" lcd.message(message_text) time.sleep(0.2) lcd.home() except KeyboardInterrupt: lcd.clear() time.sleep(1.0) * 付録（10分おきにファイルに記録） [#if7d6d68] ** 準備 [#k38a417d] ソースコードは全て/home/pi/bme280に置いておく~ データの保存先は/home/pi/bme280/dataにする~ その他必要なファイルも置いておく ** ソースコード [#v9acd243] pi@pi3b2:~/bme280$ cat bme280_csv.py #coding: utf-8 import bme280_custom import bme280_temp import bme280_pres import bme280_humid import datetime import os dir_path = '/home/pi/bme280/data' now = datetime.datetime.now() filename = now.strftime('%Y%m%d') label = now.strftime('%H:%M') date = now.strftime('%Y/%m/%d %H:%M') csv = bme280_custom.readData() csv_t = bme280_temp.readData() csv_p = bme280_pres.readData() csv_h = bme280_humid.readData() if not os.path.exists('/home/pi/bme280/data'): os.makedirs('/home/pi/bme280/data') f = open('/home/pi/bme280/data/'+filename+'.csv','a') f.write("'"+date+"',"+csv+"\n") f.close() f = open('/home/pi/bme280/data/'+filename+'_t.csv','a') f.write("'"+date+"',"+csv_t+"\n") f.close() f = open('/home/pi/bme280/data/'+filename+'_p.csv','a') f.write("'"+date+"',"+csv_p+"\n") f.close() f = open('/home/pi/bme280/data/'+filename+'_h.csv','a') f.write("'"+date+"',"+csv_h+"\n") f.close() ** crontabで10分おきに実行する [#l7769ddf] @reboot python ~/bme280/bme280_lcd.py 0,10,20,30,40,50 * * * * python ~/bme280/bme280_csv.py * モジュールの種類 [#ldda7212] ** 3.3V専用（秋月でも売ってるタイプ） [#w4e6448b] アドレス：0x77 &ref(BME-Blue.jpg); ** 3.3V/5V兼用 [#k8a25113] アドレス：0x76 &ref(BME-Purple.jpg); ** BMEとBMPの見分け方 [#h67f7b03] BMPは湿度が測れない（そのかわり安い） &ref(BME280_U.jpg); - 穴が上下方向のセンターにある（BMPは穴が角に近い） - モジュールが正方形（BMPは長方形） ~ ~ ~ &ref(BMP280.jpg); BMP280 ** BME280 Rasbee製（3.3V専用） [#i46586f8] ,SDO,CSB,SDA,SCL,GND,VCC ,PD,PU,PU,PU, , CSBがPUされているのでI2Cモード~ SDOがPDされているので、I2C Addressは0x76~ →SDOをVDDに繋ぐと0x77 &ref(BME280_Rasbee.jpg);
