Thingspeak bills itself as “an open application platform designed to enable meaninful connections between people and things.” The graphic above demonstrates how dynamic temperature level readings can be made available on the internet via Thingspeak.
In working with the Thingspeak API Sirleech has developed code he calls RestduinoThingspeak. It’s a Python script to read a RESTduino Analog pin and upload to Thingspeak. He says:
This is a great way to offload HTTP processing from your Arduino to another computer. It’s useful when you still want to be able control the Arduino over a web interface (in this case via a RESTful web service) for automation application where it’s desired to log data as well as control the device.
Below is my ThingSpeak live graph showing the outdoor light level in Mtn.View CA over the past 24 hours.
http://api.thingspeak.com/channels/627/charts/2?timescale=10&width=1000&height=600
Note: No matter how much data your channel has accumulated, ThingSpeak will not give you a graph containing data covering more than 8000 samples. So in my case, sampling every minute, I can’t see more than about 6 days of past history. (If I rewrote my hardware to upload one sample every 10 minutes, I could get about 8 weeks of storage.) See also: http://community.thingspeak.com/forum/thingspeak-api/number-of-data-recorded-in-a-chart/
Historical data is available via using the start and end parameters. That may help seeing the older data. You can always use timescale instead of altering your code. timescale=60 automatically samples your data once every 60 minutes. You can also use median=60 if you have noisy data every hour.
I have tried using timescale=60, etc. but it has no effect on the 8000 sample barrier (always the same 6 day limit, with my data stream). I’ll look for instructions about “start” and “end”, the simple tries I made resulted in no graph at all.
Good point. We might change that.
If anyone can tell me what the proper date format for start/end is, I’d love to know! I also asked here but no reply: http://community.thingspeak.com/forum/thingspeak-api/what-is-the-start-and-end-date-format/#p170
Time format is as follows: 2011-07-09 00:00:00 (%20 is an encoded space) – that’s year, month, date, hours, minutes, seconds – all 2 digits long.
http://api.thingspeak.com/channels/627/charts/2?timescale=10&width=600&height=400&start=2011-07-08%2000:00:00&end=2011-07-09%2000:00:00