I'm wanting to be able to print and update values retrieved from a small GPS in real time. For whatever reason, the code will not update the GPS value, and only prints the same value until I restart the code. My guess is the variable is not able to update, but I wouldn't know how to fix that.
while ser.inWaiting() > 0:
decoded = (ser.read(1).decode)
echo += decoded()
class GPS:
def __init__(self):
#Write GPSinput
out = ''
ser.write(com.GPSstatus.encode())
time.sleep(1)
#Read output
while ser.inWaiting() > 0:
decoded = (ser.read(1).decode)
out += decoded()
strlen = len(str(out))
substr = out[0:strlen-9]
#GPS? information list
variables = substr.splitlines()
#Storing each output in a variable
self.PULSE_SAWTOOTH = [int(s) for s in variables[1] if s.isdigit()]
self.TRACKED_SATELLITES = [int(s) for s in variables[2] if s.isdigit()]
self.VISIBLE_SATELLITES = [int(s) for s in variables[3] if s.isdigit()]
self.LONGITUDE = variables[5]
self.longlen = len(self.LONGITUDE)
self.LONGDEG = self.LONGITUDE[0:self.longlen-7]
self.LONGMIN = self.LONGITUDE[self.longlen-7:]
self.LATITUDE = variables[6]
self.latlen = len(self.LATITUDE)
self.LATDEG = self.LATITUDE[0:self.latlen-7]
self.LATMIN = self.LATITUDE[self.latlen-7:]
self.HEIGHT = variables[7]
self.KNOTS = variables[8]
self.DEGREES = [9]
self.GPS_STATUS = variables[10]
self.TIMING_MODE = variables[17]
self.FIRMWARE_VERSION = variables[20]
if __name__ == "__main__":
#Call the functions
gps = GPS()
for i in range(100):
print(gps.LATITUDE)
#Enterable Parameters
# PULSE_SAWTOOTH
# TRACKED_SATELLITES
# VISIBLE_SATELLITES
# LONGITUDE
# longlen
# LONGDEG
# LONGMIN
# LATITUDE
# latlen
# LATDEG
# LATMIN
# HEIGHT
# KNOTS
# DEGREES
# GPS_STATUS
# TIMING_MODE
# FIRMWARE_VERSION
I'm guessing this is a pretty simple solution, but I'm a beginner and I don't fully understand whats happening enough to fix it. If anyone could shed some knowledge and help with my problem it would be greatly appreciated.
Aside from the while loop indent error and possible decode error. You're getting the same output for print(gps.LATITUDE) every time because you never update it, either by the gps object, or a call to a member function of class GPS. Your initial gps object always has LATITUDE equal to the value variables[6] and if that variable isn't changing, neither will your LATITUDE variable. You have options, you can either update LATITUDE directly:
class GPS:
def __init__(self , latitudeValue = 0):
self.LATITUDE = latitudeValue
if __name__ == "__main__":
gps = GPS()
print(gps.LATITUDE) # Prints 0, default value of latitudeValue
gps.LATITUDE = 5
print(gps.LATITUDE) # Now prints 5, changed value of LATITUDE in gps object
Or you can make it part of a function call:
class GPS:
def __init__(self , latitudeValue = 0):
self.LATITUDE = latitudeValue
def updateLatitude(self , newValue):
self.LATITUDE = newValue
if __name__ == "__main__":
gps = GPS()
print(gps.LATITUDE) # Prints 0
gps.updateLatitude(10) # Updates LATITUDE VALUE
print(gps.LATITUDE) # Prints 10
You can use either method with whatever the value of variables[6] is. Likewise, you can use this with all member variables of your class.
For real-time updating you need to use a event handling function, this scenario possibly calls for a listener. Without knowing more about the device passing data through the bus. If the manufacturer of your device doesn't supply an API to work with, then while you can use a loop to constantly reinitialize an object, another approach is module reloading.
Related
i'm stuck with this problem, i can't read the variables bpm and spo2 from the function run_sensor (i need these two variables in another script). If someone can help me, thanks.
class HeartRateMonitor(object):
LOOP_TIME = 0.10
def __init__(self, print_raw=False, print_result=False):
self.bpm = 0
if print_raw is True:
print('IR, Red')
self.print_raw = print_raw
self.print_result = print_result
def run_sensor(self):
sensor = MAX30102()
ir_data = []
red_data = []
bpms = []
# run until told to stop
while not self._thread.stopped:
# check if any data is available
num_bytes = sensor.get_data_present()
if num_bytes > 0:
# grab all the data and stash it into arrays
if len(ir_data) == 100:
bpm, valid_bpm, spo2, valid_spo2 = hrcalc.calc_hr_and_spo2(ir_data, red_data) # <-------------- here
if valid_bpm:
bpms.append(bpm)
while len(bpms) > 4:
bpms.pop(0)
self.bpm = np.mean(bpms)
if (np.mean(ir_data) < 50000 and np.mean(red_data) < 50000):
self.bpm = 0
if self.print_result:
print("Finger not detected")
if self.print_result:
print("BPM: {0}, SpO2: {1}".format(round(self.bpm), round(spo2)))
You need to use Global keyword for this issue. Write this -
global bpm
global spo2
under the function you need to use the variables in
You can't access class variables from another function. However, if you were to create an instance of the HeartRateMonitor class, then you can import it and get its bpm and spo2.
instance = HeartRateMonitor()
Then, in your other script:
from heartratemonitor.py import instance
instance.run_sensor() # I assume this is what you want to do
print(instance.bpm)
print(instance.spo2)
Apologies for this newbie question. I'm not sure if I even phrased it correctly.
I have a class inside a function that lists a bunch of variables, and I want to be able to choose which variables are printed and returned at the final function call. However, I clearly don't understand enough about objects to accomplish this, because it raises errors when I try to attempt something.
def gpscall(call):
#Write GPSinput
out = ''
ser.write(com.GPSstatus.encode())
time.sleep(1)
#Read output
while ser.inWaiting() > 0:
decoded = (ser.read(1).decode)
out += decoded()
strlen = len(str(out))
substr = out[0:strlen-9]
#GPS? information list
variables = substr.splitlines()
#Storing each output in a variable
class GPS:
PULSE_SAWTOOTH = [int(s) for s in variables[1] if s.isdigit()]
TRACKED_SATELLITES = [int(s) for s in variables[2] if s.isdigit()]
VISIBLE_SATELLITES = [int(s) for s in variables[3] if s.isdigit()]
LONGITUDE = variables[5]
longlen = len(LONGITUDE)
LONGDEG = LONGITUDE[0:longlen-7]
LONGMIN = LONGITUDE[longlen-7:]
LATITUDE = variables[6]
latlen = len(LATITUDE)
LATDEG = LATITUDE[0:latlen-7]
LATMIN = LATITUDE[latlen-7:]
HEIGHT = variables[7]
KNOTS = variables[8]
DEGREES = [9]
GPS_STATUS = variables[10]
TIMING_MODE = variables[17]
FIRMWARE_VERSION = variables[20]
print (call)
return (call)
if __name__ == "__main__":
#Call the functions
gpscall(gpscall.GPS.LATITUDE)
This raises the error,
Function 'gpscall' has no 'GPS' member.
I don't understand why it cannot see the class, I think I'm using the function parameters incorrectly.
Any help with my poorly written code would be greatly appreciated.
Perhaps something like so is your intention? __init__ will initialize the object, and the self. will "save variables to the object."
class GPS:
def __init__(self):
#Write GPSinput
ser.write(com.GPSstatus.encode())
#Read output
out = ''
while ser.inWaiting() > 0:
decoded = (ser.read(1).decode)
out += decoded()
#GPS information list
substr = out[0:len(str(out))-9]
variables = substr.splitlines()
self.PULSE_SAWTOOTH = [int(s) for s in variables[1] if s.isdigit()]
self.TRACKED_SATELLITES = [int(s) for s in variables[2] if s.isdigit()]
self.VISIBLE_SATELLITES = [int(s) for s in variables[3] if s.isdigit()]
self.LONGITUDE = variables[5]
self.LONGDEG = LONGITUDE[0:len(LONGITUDE)-7]
self.LONGMIN = LONGITUDE[len(LONGITUDE)-7:]
self.LATITUDE = variables[6]
self.LATDEG = LATITUDE[0:len(LATITUDE)-7]
self.LATMIN = LATITUDE[len(LATITUDE)-7:]
self.HEIGHT = variables[7]
self.KNOTS = variables[8]
self.DEGREES = variables[9]
self.GPS_STATUS = variables[10]
self.TIMING_MODE = variables[17]
self.FIRMWARE_VERSION = variables[20]
gps = GPS()
print(gps.GPS_STATUS)
Yor cls inside the function is perfect and there is nothing wrong there. You are just trying to call the function and the cls objects in a wrong way.
if __name__ == "__main__":
#Call the functions
gpscall(gpscall.GPS.LATITUDE) <---- ERROR HERE
gpscall is a function, so when you are trying to access GPS.LATITUDE, it won't find any objects. You would have to do either this
gpscall(gpscall("").GPS.LATITUDE)
But I think the best way to do this is to write the func inside the cls. You will still be able to access all the variables of the cls, and it won't create much hassle.
PS: That's a good question, not a noob one. Good luck (y)
I have a problem that involves collecting data continuously from multiple sources.
My setup as it is currently, writes each data entry from each source to a MySQL db, and then, with another python program, does Select's that bring all the data together. I need to make INSERT's at roughly 1000/second and as it is my SELECT's can take 15-20 seconds each.
The whole process takes so long the data is obsolete before I get to do anything useful with it.
I have created a toy example to try and demonstrate what I am looking for.
program 1 'generateClasses':
import time
import random
from datetime import datetime
class Race:
def __init__(self,name):
hist = {}
now = datetime.now()
self.name = name
self.now = now
hist[now] = 0
self.v = 0
self.hist = hist # example variable's.
def update(self,name,v):
now = datetime.now()
hist = self.hist
hist[now] = v
self.v = v
self.now - now
self.hist = hist
class Looper:
def __init__(self,name):
self.a = Race(name)
def loop(self,name):
# simulating the streaming API
while True:
v = self.a.v
v += 1
self.a.update(name,v)
print(a,datetime.now(),v) # can i access this stream using the location displayed with the print(a)?
time.sleep(0.1) # this should be more like time.sleep(0.001)
def pickData(self,name):
v = self.v
self.loop(name)
print('The state at {} {} = '.format(self.now,self.v))
return self.hist
if __name__ == "__main__":
x = 'Some_ID'
a = Looper(x)
a.loop(x)
program 2:
from generateClasses import Looper
from datetime import datetime
import time
start_time = int((datetime.now() - datetime(1970, 1, 1)).total_seconds())
print(start_time)
x = 'Some_orher_ID'
a = Looper(x)
print('this will print')
a.loop(x)
print('this wont ever print')
a.pickdata(x)
# this last section is the functionality i am looking for in this program, but, as it is, it will never run.
x = ‘Some_ID’
while True:
now_time = int((datetime.now() - datetime(1970, 1, 1)).total_seconds())
print(start_time)
if int(now_time-start_time) == 10:
a.pickData(x)
# b.pickData(x)
# c.pickData(x)
# d.pickData(x)
# make further actions.....
What happens currently in my examples is that it creates its own loop using the class structure from the first program.
What I want it to do is call the the pickData() method from program 2 at timely intervals of my choosing on a loop running in another program.
Is my best option picking a db located in memory and getting a faster computer?
Maybe something can be done with the object location shown when you print the instance name?
I have uploaded to github if anybody fancies it..
I would be grateful of any suggestions.
also, recommendations for further reading would be appreciated also.
Id, conf = recognizer.predict(gray[y:y+h,x:x+w]
def hour(cn):
for z in range(9,17):
if now.hour == z:
worksheet(cn, str(z)+":00")
def identify(number):
sht = gc.open("Test")
wks3 = sht.worksheet("NAMES")
b = wks3.acell('B'+str(number)).value
a = wks3.acell('A'+str(number)).value
if(Id == a and conf<65):
print(Id, conf)
Id = str(b)
Time = time.ctime()
hour(number)
elif(conf>64):
print(conf)
Id = "Unknown"
for m in range(2,100):
identify(m)
The above code is being used for facial recognition, I copied what I felt was necessary, it is not the entire code.
I'm trying create a function which I want to call back in a for loop
What am I doing wrong? I've been looking t this for 6 hours now, and anything I try doesn't seem to work.
I get a message back saying "UnboundLocalError: local variable 'Id' referenced before assignment"
It's impossible because I'm assigning with:
a = wks3.acell('A'+str(number)).value
So it grabs the ID number from the google spread sheet and checks if it is equaled to that, can someone tell me where I'm going wrong here?
def identify(number):
sht = gc.open("Test")
wks3 = sht.worksheet("NAMES")
b = wks3.acell('B'+str(number)).value
a = wks3.acell('A'+str(number)).value
#because you did, Id = ?
if(Id == a and conf<65):
print(Id, conf)
Id = str(b)
Time = time.ctime()
hour(number)
elif(conf>64):
print(conf)
Id = "Unknown"
Because you did, variable Id isn't passed as any parameter or global/local variable or as an argument to existing class.
If Id was parameter:
def identify(number,Id):
If Id was global variable:
def identify(number):
global Id
If Id was local variable:
def identify(number):
id = None # or some other data type
And if Id was argument from some class:
some_class.Id
In short you referenced Id before it was initialised. This is rookie mistake and there is some stuff where you can actually init a variable in if elif else statement but you need to trow a none of above logic of the rule.
if True: Id = 2; elif False: Id = 3; else: Id =0 #this is pseudocode, don't paste it in.
Also have in mind that next variable is also Unbound conf
EDIT:
Often to avoid this problem we write code like this:
def somefunction(parm1,parm2... ):
# global variables : description for variable stack is optional
global var1,var2 # if needed
#local variables
var3,var4 = None;
var5 = 'something else'
#in body functions : functions inside functions or just general program functions
def a(... ): return ...
#body : actually what function/program does.
# returning , finishing statement.
Language: Python
I want the value of a variable to be initialized to zero at the start of the execution. This variable is used in a function & its value may also get changed within the function. But I do not want the value of this variable to reset to zero whenever a function call is made. Instead, its value should be equal to the updated value from its previous function call.
Example:
get_current() is constantly returning a different value when it is called.
ctemp is initially zero.
In the first function call get_current_difference() will return cdiff & then update the value of ctemp such that ctemp = current.
In the second function call, the value of ctemp should not be zero. Instead, it should be equal to the updated value from the first function call.
import serial
arduino = serial.Serial('/dev/ttyACM1',9600)
ctemp = 0
def get_current():
line = arduino.readline()
string = line.replace('\r\n','')
return string
def get_current_difference():
global ctemp
current = get_current()
cdiff = float(current) - ctemp
return cdiff
ctemp = current
while 1:
current = get_current_difference()
print(current)
You return before setting value of ctemp
return cdiff
ctemp = current
must become
ctemp = current
return cdiff
You are describing mutable state and a function to modify it, which is what classes are for.
class Temperature:
def __init__(self, arduino):
self.ctemp = 0
self.arduino = arduino
def current(self):
line = self.arduino.readline()
return line.replace('\r\n', '')
def difference(self):
current = self.current()
cdiff = float(current) - self.ctemp
self.ctemp = current
return cdiff
t = Tempurature(serial.Serial('/dev/ttyACM1', 9600)
while True:
print(t.difference())
Using a class scales if, for example, you have multiple temperature monitors to work with.