Disappearing data: downloaded excel data that was posted by python script is missing and not visible in widget
Hi,
I get 200 after a Python post to a channel like this from my Python script:
Ambient light: 13.3 lux Mass is 943.6 g 10:37 that is today, 7/24/2021 Pacific time <Response [200]
Yet the data is not showing up in the widget after 03:07 today and when I export the data it agrees with that:
2021-07-24 02:57:17 MDT 4123 947.4597598 0.833333333
2021-07-24 03:07:18 MDT 4124 947.5867868 0.833333333
here is a code snippet: note it posts every 10 minutes
-----------
request_headers = {'Content-Type':'application/json'}
try:
response = requests.post('http://api.thingspeak.com/update?api_key=' + API_KEY,
json=planta_json, headers=request_headers)
print(response)
except:
print("did not post for some reason")
------------
i never get a "did not post for some reason" debug message from the Python script. its like the data just disappears for some reason.
is there something else in the response i should look at to see why this happens? it will work fine for days then do this.
thanks
5 Kommentare
Zeit (absteigend)
and there is no Averaging or other things going on in the widget
I believe it has to do with the code sending data to ThingSpeak. Clearly one of your other channels is working: https://thingspeak.com/channels/1412172
Maybe you need to check the difference between the code posting to this channel vs the code posting to this channel: https://thingspeak.com/channels/1316073
Hi Vinod ok thanks and yes i thought so as well but here is the deal and I think its a code problem - maybe. All of the fields 1,2,3,4,5,6 in this channel https://thingspeak.com/channels/1412172 are bring driven from 3 different devices using the same exact Python code that I copied and pasted above. Notice that Fields 1 and 2, which is a device in Oregon, has never failed completely (there is missing data due to WiFi but otherwise it has been solid for almost a month). Fields 3 and 4 are the ones that stop posting for some reason but that device is in San Diego. So I did an experiment with a 4th test device here are home with the same exact Python code posting to Fields 7 and 8. That is where I saw the problem again with missing data even though my debug message gave me the status OK after posting data.
I have another channel using Arduino code / Arduino c++ API that has never failed: https://thingspeak.com/channels/798053, but that is only 1 device posting ( at the moment... my pool sensor died due to overheating in the Arizona heatwave a few weeks ago.;-)
Therefore suspecting the Python code in the trouble channels I changed the 4th test device using Python code posting to the above field 7 and 8 but different code:
# trying the new way to post
params = urllib.parse.urlencode({'field7':str(weight), 'field8':str(ambient_lux),'key':API_KEY})
headers = {"Content-type": "application/x-www-form-urlencoded","Accept": "text/plain"}
conn = http.client.HTTPConnection("api.thingspeak.com:80")
try:
conn.request("POST", "/update", params, headers)
response = conn.getresponse()
print(datetime.now().strftime("%H:%M"))
print(response.status, response.reason)
conn.close()
except:
print("did not post for some reason, connection failed")
finally:
time.sleep(SLEEP_TIME)So now I wonder ... what is the 'best' Python API usage? Notice before I never checked the channel connection nor did I close the channel connection. Now I do. Is there a 'really good' Python example you can show me ?
thanks ! Mark
If you have 4 devices posting to the same channel, how are you keeping their clocks synchronized?
Note that a channel can be updated at most every 15 seconds with a free license and at most once a second with a paid license. If you have multiple devices posting to the same channel, and their updates overlap within window I just mentioned, the second device will just get a 200 HTTP status code with a "0" in the response.
The mental model to use is each channel can be updated by one device/MCU with up to 8 sensors (i.e. fields on ThingSpeak) per device. If you have multiple devices, they should really be posting to multiple channels.
Vinod AH.. ok so that is something I never knew! that explains the missing data holes from time to time but since these things are not time sync'd in any way I would be surprised if they hit the 15 second window for days at a time..but maybe it is possible. Ok so I will next time set up one channel per device. thanks for the explanation.
So.. given these are basically Raspberry Pi Zero W devices their on board clock is not very good.. and they all started at random times by different people so I find it hard to believe they could line up posting times that closely, as matter of fact you can see in the data they are usually minutes apart... but maybe
