Just started to experiment logging data to GroveStreams.com using Arduino UNO + Ethernet Shield.
Used the example code from Grovestreams.com and modified it to work with DHT22 TempSensor. In total I´d like to have 4 sensors logging temperature and humidity every 30 - 60 min.
Logging data from one sensor seems to be working for a couple of hours. Adding more sensors will upload one set of data and then fail. Suppose that the reson for this is that my Arduino runs out of memory ?!
I will try it out with an Arduino Mega that has a lot more memory....
Anyone with the same experience? Any suggestions how to make logging work with multiple sensors using the Arduino UNO?
It might help if you posted your code. There should not be a memory problem as you should be simply reading the sensor and passing the data straight through to Grovestreams. I recognise that logging every 30 minutes seems a long time but you make no mention of accumulating more frequent data.
I added the DHT library and also some memory monitoring code from desert-home.com. Code is made to handle 4 different DHT22. Howerver, just one DHT is "active" in code. I have attached the code Grovestreams_DHT.txt
OK, I'm guessing a bit here but I think you are right, you are running out of memory but this is caused by junk or, at best, inappropriate code. I submit the problem is all that String stuff clogging up the works, and using a Mega will probably do no more than delay the inevitable.
I'm afraid I can't help much as, even if I have correctly identified the problem, my solution is to avoid having anything to do with strings.
I have lost heart with Grovestreams and have stuck with Xively for the moment. You might get some useful information here.
Draythomp is the guru of choice for this stuff and is OK with Grovestreams!
You may find the problem is simply one of properly presenting the data.
Having said the above about the Mega, I think they are more appropriate for thsi sort of work, but that is because of the size the programme can get to be.