Pytrack GPS library

[tttadam]

Hi there!

Can you recommend me a library for pytrack?
What's in the documentation is very basic.
It would be nice to get information some additional information like, time, altitude, speed, Visible satelites, etc?
What library did you used and what was the project?
(I am working on a weather ballon)

Thanks! :)

[jcaron]

@tttadam

You may want to get a look at:

• https://github.com/inmcm/micropyGPS
• https://github.com/andrethemac/L76GLNSV4/blob/master/L76GNSV4.py

Note that both are linked to in the Pytrack examples page.

[tttadam]

@jcaron Yes you are right, I wasn't profound enough.
micropyGPS looks really powerful. However, It's not clear for me how to use it.
Because this library for uart, but pytrack use I2c am I missing something?
Is there a sample code where I can start? micropyGPS use predifined gps sentences.
Thanks in advance.

[jcaron]

@tttadam micropyGPS does not handle the I/O, it's up to you to feed it the data using the update function.

You'll find an example here: https://github.com/gregcope/L76micropyGPS

The core of it is really just:

    while True:
        # get some NMEA data
        someNmeaData = str(self.i2c.readfrom(GPS_I2CADDR, 128))

        # Pass NMEA data to micropyGPS object
        for x in someNmeaData:
            self.my_gps.update(str(x))
        time.sleep(0.25)

[tttadam]

@jcaron Thank you.

[tttadam]

I am having some issues with L76micropyGPS.py library, if I want to use the I2C.
When I create an I2C object in the main.py

i2c=I2C(0, I2C.MASTER)

I got an OSError: I2C bus error in L76micropyGPS.py at line 54.
I think it because me and the library both want to use I2C. But I would like to work with a temperature sensor wich communicates in I2C, and later I would like to chain other envirement sensors (as far as I know I can use multiple external sensor on the same pins. )

[jcaron]

@tttadam unless you provide the full code you are using and full details of what is connected where there’s very little chance anybody is going to be able to help you.

[tttadam]

@jcaron Fair enough, sorry. :)

This is how my boot.py looks like,
the GPS set up is from line 50 to 60. This part is run alright, expect some rare cases minor issues with the rtc setup:

# # this runs first
# #TODO: CLEAN IT up, SD Class(inprogress),
import pycom
import os
import math
import machine
from machine import SD, Pin, UART
from pytrack import Pytrack
import utime
import time
import _thread
import gc
from L76micropyGPS import L76micropyGPS
from micropyGPS import MicropyGPS
#my classes
from  rgbsignal import RGBSignal
from sdlogger import SDLogger

uart = UART(0, baudrate=115200)
os.dupterm(uart)

#TODO:test it, 	outsource it
runcount = pycom.nvs_get('runcount')
print("The current value of the run counter is: "+str(runcount))
pycom.nvs_set('runcount', runcount+1)

# this is the led notification class
fb = RGBSignal() 

#the main file will be called
machine.main('main.py')

#buttonpin = Pin('G17', mode= Pin.IN, pull=Pin.PULL_UP) #button pin on expansion board
buttonpin = Pin('G4', mode= Pin.IN, pull=Pin.PULL_UP) #button pin on pytrack board
start = True
print("Push the button for start booting")
#def message(self, color="cyan", interval=0.5, iteration=3):
_thread.start_new_thread(fb.message, ["cyan",0.1,0.3])
while start:
    utime.sleep_ms(10)
    if buttonpin() == 0:
        start = False
_thread.start_new_thread(fb.startup, [])
print("Boot file process is started.")

gc.enable()
print("GC is enabled")
print("Free Mem: {}".format(gc.mem_free()))

#Setting up the gps:
py = Pytrack()
my_gps = MicropyGPS(local_offset=1,location_formatting='dd')
L76micropyGPS = L76micropyGPS(my_gps, py)
gpsThread = L76micropyGPS.startGPSThread()
print("Waiting for gps signal")
counter = 0
while (my_gps.timestamp == (0, 0, 0)):
    print("Waiting for gps signal: "+str(counter)+" "+str(my_gps.date)+" "+str(my_gps.timestamp))
    counter +=1
    time.sleep(2)
time.sleep(4)
print("Date: "+str(my_gps.date))
print("GPS signal is found")
print("Time: "+str(my_gps.timestamp))
time.sleep(2)
print(my_gps.date[0])
print(my_gps.date[1])
print(my_gps.date[2])


print("Setting up the RTC")
rtc = machine.RTC()
print("RTC before init: {}".format(rtc.now()))
dateYear = int(str(20) + str(my_gps.date[2]))
rtc.init((dateYear, my_gps.date[1], my_gps.date[0], my_gps.timestamp[0], my_gps.timestamp[1], int(my_gps.timestamp[2]), 0, 0)) #seting up the rtc 
print("RTC is set : {}".format(rtc.now()))




#Create logstructure after GPS initalizaed
dataLogger = SDLogger(uart)
dataLogger.sdFormat()
foldername = str("Flight_"+
             str(runcount)+"_"+
             str(dateYear)+"-"+
             str(my_gps.date[1])+"-"+
             str(my_gps.date[0])+"_"+
             str(my_gps.timestamp[0])+"-"+
             str(my_gps.timestamp[1])+"-"+
             str(int(my_gps.timestamp[2])))

dataLogger.createFolder(foldername)
logfilename = str("LogOfRun"+"_"+
          str(runcount)+"_"+
          str(dateYear)+"-"+
          str(my_gps.date[1])+"-"+
          str(my_gps.date[0])+"_"+
          str(my_gps.timestamp[0])+"-"+
          str(my_gps.timestamp[1])+"-"+
          str(int(my_gps.timestamp[2])))
logheader = "TimeStamp;GPSTimeStamp;Sensor;Value;Location"
dataLogger.creatLogFile(logheader,logfilename)
# #TODO: Create separate log for sytemlog, telemetry, and sensor data

After the boot.py main.py is next, This fails at line 30, when I create the I2C object. With an OSError: I2C bus error in L76micropyGPS.py at line 54.

from machine import I2C, Pin, UART
import machine
from SI7021 import SI7021
import gc
import _thread
#my classes
from  rgbsignal import RGBSignal
from sdlogger import SDLogger


start = True
buttonpin = Pin('G4', mode= Pin.IN, pull=Pin.PULL_UP) #button pin on pytrack board
_thread.start_new_thread(fb.message, ["yellow",0.1,3])
print("Push the button for start main")
while start:
    time.sleep_ms(10)
    if buttonpin() == 0:
        start = False
_thread.start_new_thread(fb.startup, [])


print("Main has started")
print("Free Mem: {}".format(gc.mem_free()))
i2c=I2C(0, I2C.MASTER)
print(i2c.scan())

[tttadam]

This post is deleted!

[tttadam]

I found the issue.
I gave my I2C object an ID = 1, and that solved the issue.

[gregcope]

@tttadam Hi. Looks like you might have found my L76micropyGPS.py useful. Any feedback welcome! I just updated the doco as the issue has been resolved, and I had not updated the README.