I have a Raspberry Pi Zero and I am using it for a project in witch I have to measure the temperature and pressure and write those values inside a txt file located in a folder called Harvest, that is located in the boot folder (path: /boot/Harvest/temp_and_press_sensor.txt ). The sensor that I am using is a BMP388. In the code, I have a lot of stuff to read the values coming form the GPIO pins and at the end I have more code to read the temperature and pressure values, open the txt file, write those values and close, and then wait some time and then repeat the process. The code is:
import time
import datetime
import sys
import smbus
import spidev
import RPi.GPIO as GPIO
from math import pow
class DFRobot_BMP388:
def __init__(self):
self.op_mode = 0
self.par_t1 = 0
self.par_t2 = 0
self.par_t3 = 0
self.par_p1 = 0
self.par_p2 = 0
self.par_p3 = 0
self.par_p4 = 0
self.par_p5 = 0
self.par_p6 = 0
self.par_p7 = 0
self.par_p8 = 0
self.par_p9 = 0
self.par_p10 = 0
self.par_p11 = 0
chip_id = self.bmp3_get_regs(0x00, 1)[0]
if (chip_id != 0x50):
print("chip id error!")
sys.exit()
return
self.get_calib_data()
self.set_config()
def get_calib_data(self):
calib = self.bmp3_get_regs(0x31,21)
self.parse_calib_data(calib)
def uint8_int(self,num):
if(num>127):
num = num - 256
return num
def parse_calib_data(self,calib):
temp_var = 0.00390625
self.par_t1 = ((calib[1]<<8)|calib[0])/temp_var
temp_var = 1073741824.0
self.par_t2 = ((calib[3]<<8)|calib[2])/temp_var
temp_var = 281474976710656.0
calibTemp = self.uint8_int(calib[4])
self.par_t3 = (calibTemp)/temp_var
temp_var = 1048576.0
calibTempA = self.uint8_int(calib[6])
calibTempB = self.uint8_int(calib[5])
self.par_p1 = ((calibTempA|calibTempB)-16384)/temp_var
#print((calibTempA<<8)|calibTempB)
temp_var = 536870912.0
calibTempA = self.uint8_int(calib[8])
calibTempB = self.uint8_int(calib[7])
self.par_p2 = (((calibTempA<<8)|calibTempB)-16384)/temp_var
#print((calibTempA<<8)|calibTempB)
temp_var = 4294967296.0
calibTemp = self.uint8_int(calib[9])
self.par_p3 = calibTemp/temp_var
#print(calibTemp)
temp_var = 137438953472.0
calibTemp = self.uint8_int(calib[10])
self.par_p4 = calibTemp/temp_var
#print(calibTemp)
temp_var = 0.125
self.par_p5 = ((calib[12]<<8)|calib[11])/temp_var
#print((calib[12]<<8)|calib[11])
temp_var = 64.0
self.par_p6 = ((calib[14]<<8)|calib[13])/temp_var
#print((calib[14]<<8)|calib[13])
temp_var = 256.0
calibTemp = self.uint8_int(calib[15])
self.par_p7 = calibTemp/temp_var
#print(calibTemp)
temp_var = 32768.0
calibTemp = self.uint8_int(calib[16])
self.par_p8 = calibTemp/temp_var
#print(calibTemp)
temp_var = 281474976710656.0
self.par_p9 = ((calib[18]<<8)|calib[17])/temp_var
#print((calib[18]<<8)|calib[17])
temp_var = 281474976710656.0
calibTemp = self.uint8_int(calib[19])
self.par_p10 = (calibTemp)/temp_var
#print(calibTemp)
temp_var = 36893488147419103232.0
calibTemp = self.uint8_int(calib[20])
self.par_p11 = (calibTemp)/temp_var
#print(calibTemp)
def set_config(self):
settings_sel = 2|4|16|32|128
self.bmp3_set_sensor_settings(settings_sel)
self.op_mode = 0x03
self.write_power_mode()
def bmp3_set_sensor_settings(self,settings_sel):
#set_pwr_ctrl_settings
reg_data = self.bmp3_get_regs(0x1b,1)[0]
if(settings_sel & 2):
reg_data = (reg_data&~(0x01))|(0x01&0x01)
if(settings_sel & 4):
reg_data = (reg_data&~(0x02))|((0x01<<0x01)&0x02)
#data = bytearray(1)
data = [reg_data]
#print(data)
#print(data[0])
self.bmp3_set_regs(0x1b,data)
def write_power_mode(self):
op_mode_reg_val = self.bmp3_get_regs(0x1b,1)[0]
op_mode_reg_val = (op_mode_reg_val&~(0x30))|((self.op_mode<<0x04)&0x30)
#data = bytearray(1)
#data[0] = op_mode_reg_val
data = [op_mode_reg_val]
self.bmp3_set_regs(0x1b,data)
def readTemperature(self):
return round(self.bmp3_get_sensor_data(2),2)
def readPressure(self):
return round(self.bmp3_get_sensor_data(1),2)
def bmp3_get_sensor_data(self,sensor_comp):
rslt = self.bmp3_get_regs(0x04,6)
#parse_sensor_data
xlsb = rslt[0]
lsb = rslt[1] << 8
msb = rslt[2] << 16
uncomp_pressure = msb|lsb|xlsb
xlsb = rslt[3]
lsb = rslt[4] << 8
msb = rslt[5] << 16
uncomp_temperature = msb|lsb|xlsb
#print(uncomp_temperature)
value = self.compensate_data(sensor_comp,uncomp_pressure,uncomp_temperature)
return value
def compensate_data(self,sensor_comp,uncomp_pressure,uncomp_temperature):
if(sensor_comp & 0x03):
value = self.compensate_temperature(uncomp_temperature)
if(sensor_comp & 0x01):
value = self.compensate_pressure(uncomp_pressure,value)
return value
def compensate_temperature(self,uncomp_temperature):
uncomp_temp = uncomp_temperature
partial_data1 = (uncomp_temp - self.par_t1)
partial_data2 = (partial_data1 * self.par_t2)
comp_temp = partial_data2 + (partial_data1 * partial_data1)*self.par_t3
return comp_temp
def compensate_pressure(self,uncomp_pressure,t_lin):
partial_data1 = self.par_p6 * t_lin
partial_data2 = self.par_p7 * pow(t_lin, 2)
partial_data3 = self.par_p8 * pow(t_lin, 3)
partial_out1 = self.par_p5 + partial_data1 + partial_data2 + partial_data3
#print(partial_data1,partial_data2,partial_data3)
#print(partial_out1)
partial_data1 = self.par_p2 * t_lin
partial_data2 = self.par_p3 * pow(t_lin, 2)
partial_data3 = self.par_p4 * pow(t_lin, 3)
partial_out2 = uncomp_pressure *(self.par_p1-0.000145 + partial_data1 + partial_data2 + partial_data3)
#print(partial_out2)
partial_data1 = pow(uncomp_pressure, 2)
partial_data2 = self.par_p9 + self.par_p10 * t_lin
partial_data3 = partial_data1 * partial_data2
partial_data4 = partial_data3 + pow(uncomp_pressure, 3) * self.par_p11
#print(partial_data4)
comp_press = partial_out1 + partial_out2 + partial_data4
#print(comp_press)
#print(t_lin)
return comp_press;
def readCalibratedAltitude(self,seaLevel):
pressure = self.readPressure()
return round((1.0 - pow(pressure / seaLevel, 0.190284)) * 287.15 / 0.0065,2)
def readSeaLevel(self, altitude):
pressure = self.readPressure()
return round(pressure / pow(1.0 - (altitude / 44330.0), 5.255),2)
def readAltitude(self):
pressure = self.readPressure()
return round((1.0 - pow(pressure / 101325, 0.190284)) * 287.15 / 0.0065,2)
def INTEnable(self):
reg_data = [0x40]
reg_addr = 0x19
self.bmp3_set_regs(reg_addr, reg_data)
def INTDisable(self):
reg_data = [0x00]
reg_addr = 0x19
self.bmp3_set_regs(reg_addr, reg_data)
class DFRobot_BMP388_SPI(DFRobot_BMP388):
def __init__(self,cs):
self.spi = spidev.SpiDev(0,0)
self.cs = cs
GPIO.setwarnings(False)
GPIO.setmode(GPIO.BCM)
GPIO.setup(self.cs, GPIO.OUT,initial=1)
super(DFRobot_BMP388_SPI,self).__init__()
def bmp3_get_regs(self,reg,len):
regAddr = [reg|0x80]
GPIO.output(self.cs,0)
self.spi.xfer(regAddr)
rslt = self.spi.readbytes(len+1)
GPIO.output(self.cs,1)
data = bytearray(len)
for i in range(0,len):
data[i] = rslt[i+1]
return data
def bmp3_set_regs(self,reg,data):
value = []
for i in range(0,len(data)):
value.append(data[i])
regAddr = [reg&0x7f]
GPIO.output(self.cs,0)
self.spi.xfer(regAddr)
self.spi.xfer(value)
GPIO.output(self.cs,1)
class DFRobot_BMP388_I2C(DFRobot_BMP388):
def __init__(self, addr):
self._addr = addr
self.i2c = smbus.SMBus(1)
super(DFRobot_BMP388_I2C,self).__init__()
def bmp3_get_regs(self,reg,len):
rslt = self.i2c.read_i2c_block_data(self._addr,reg,len)
return rslt
def bmp3_set_regs(self,reg,data):
self.i2c.write_i2c_block_data(self._addr,reg,data)
# Create a bmp388 object to communicate with I2C.
bmp388 = DFRobot_BMP388_I2C(0x77)
#first
time.sleep(300)
ground_level = 470.0
seaLevel = bmp388.readSeaLevel(ground_level)
altitude = bmp388.readCalibratedAltitude(seaLevel)
temp = bmp388.readTemperature()
pres = bmp388.readPressure()
now = datetime.datetime.now()
file = open("/boot/Harvest/temp_and_press_sensor.txt", "a")
file.write(now.strftime("%Y/%m/%d %H:%M:%S") + " - TEMP: %s ºC" %temp + " | PRESS: %s Pa" %pres + "\n")
file.close()
#second
time.sleep(14100)
ground_level = 470.0
seaLevel = bmp388.readSeaLevel(ground_level)
altitude = bmp388.readCalibratedAltitude(seaLevel)
temp = bmp388.readTemperature()
pres = bmp388.readPressure()
now = datetime.datetime.now()
file = open("/boot/Harvest/temp_and_press_sensor.txt", "a")
file.write(now.strftime("%Y/%m/%d %H:%M:%S") + " - TEMP: %s ºC" %temp + " | PRESS: %s Pa" %pres + "\n")
file.close()
#thirth
time.sleep(14400)
ground_level = 470.0
seaLevel = bmp388.readSeaLevel(ground_level)
altitude = bmp388.readCalibratedAltitude(seaLevel)
temp = bmp388.readTemperature()
pres = bmp388.readPressure()
now = datetime.datetime.now()
file = open("/boot/Harvest/temp_and_press_sensor.txt", "a")
file.write(now.strftime("%Y/%m/%d %H:%M:%S") + " - TEMP: %s ºC" %temp + " | PRESS: %s Pa" %pres + "\n")
file.close()
#fourth
time.sleep(14400)
ground_level = 470.0
seaLevel = bmp388.readSeaLevel(ground_level)
altitude = bmp388.readCalibratedAltitude(seaLevel)
temp = bmp388.readTemperature()
pres = bmp388.readPressure()
now = datetime.datetime.now()
file = open("/boot/Harvest/temp_and_press_sensor.txt", "a")
file.write(now.strftime("%Y/%m/%d %H:%M:%S") + " - TEMP: %s ºC" %temp + " | PRESS: %s Pa" %pres + "\n" + "\n")
file.close()
I want this code to run every time I power my raspberry, so, in the terminal, I typed: sudo crontab -e, and choose nano. And then I wrote: @reboot python /home/pi/Desktop/Harvest/bmp388.py & and save it. The problem that I am facing is that when I run the code from the python editor everything works and the values are written in the txt file, but when I reboot my rpi and wait the time necessary to run and write inside the txt file, it never does. I even tried to create a txt file and then write inside this new file, but does noting, so I am assuming that the code is not running. I found it stranger because, inside the crontab, I also have another line of code to run a different program at reboot and this program runs every single time.
Do you know what might be the problem?
Thank you, Afonso
