I have been adding GPS logging to my Bicycle Dashcam. All of the example Python code (eg: https://gpsd.gitlab.io/gpsd/gpsd-client-example-code.html) I’ve found online throws this error after about a minute:
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Exception has occurred: KeyError'el'File "example2.py", line 12, inwhile 0 == session.read():KeyError: 'el'
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I’m not sure if this is a problem unique to my GPS receiver, but it regularly sends data that is not “class”:“TPV” (eg: “class”:“SKY”) - TPV is the data with coordinates, and whenever that happens, all the sample code throws a KeyError.
I’ve found the easiest way to fix this is to add a TRY/EXCEPT inside the forever loop, catch the KeyError expection, and PASS. Here is an adaptation of code I found on Stackoverflow that solves the problem - I’ve submitted it as an improvement, hopefully they accept my edits!
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import threading
import time
from gps import *
from datetime import datetime
class GpsPoller(threading.Thread):
def __init__(self):
threading.Thread.__init__(self)
self.session = gps(mode=WATCH_ENABLE)
self.current_value = None
def get_current_value(self):
return self.current_value
def run(self):
while True: #moved the try INTO the forever loop, so pass from the except resumes collecting data
try:
self.current_value = self.session.next()
time.sleep(0.2) # tune this, you might not get values that quickly
except KeyError as e: #catch the KerError, and return to the forever loop
pass
except StopIteration:
pass
#if __name__ == '__main__':
gpsp = GpsPoller()
gpsp.start()
# gpsp now polls every .2 seconds for new data, storing it in self.current_value
while 1:
# In the main thread, every 5 seconds print the current value
time.sleep(5)
value=gpsp.get_current_value()
print(value)
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Update (May 6, 2023): I found a better solution: the gpsd-py3 library works great.
