best way to log and display data online

hi all, im getting a dht22 temp reading every 2mins and id like to log the data so i can easy manipulate it and display it online. id like to build a web page where i can see graphs of the temp readings per deay, month, year etc as well as max, min and avg of the temp in the time frame the user selected.

i was wondering which is the best way to log the data, so it can be displayed and graphed easily in a php/js page.

one approach would be using a mysql database but i wouldnt like to run a server 24/7
another one is to log the data on an sd card in csv but i really dont know if its easy to access it and uploaded on a web page using graphs, gauces etc.
3rd would be to use an app like thingspeak, plotly but i know theyve got limitations on the plots and the data uploaded.

any help and ideas would be appreciated.

thanks. :grinning:

I think you have too many options for me to be able to suggest anything.

If you don't want to run a server 24/7 then your Arduino must have somewhere to store data until it is time to upload it. An SD Card would probably be suitable.

But if you don't upload the data as it is collected you will need to consider whether there is sufficient time to upload all the data that has collected on the SD Card.

Another question is whether you want to store the data permanently on the server or whether you are content for it to flash past the user and be gone forever. A database such as MySql or SQlite would be convenient for storing data on the server.

How are you going to host your server?

This EzScrn demo may be of some interest. As written, the server to not store the data, but it could easily be adapted to do so.


yeah id like the data to be stored permanently. the server would run ideally on the ehternet shield sd card. i dont want to have a pc running 24/7

You might also look into uploading your data to one of the several IoT (Internet of Things) websites. I have had a free account on Xively for a couple of years now.

From my Arduino Ethernet shield or Wi-Fi Shield I am able to upload data (RGB LED data in my case) to my "device" on Xively. I upload once per minute, RGB values between 8-255, but you can set up your data anyway you want. This site is ideal for temperature measurements and other sensor data logging.

Then I can log into Xively from any where with an internet browser and I can see my data logged and graphed.

You might consider something like this.

The site you want to start with is:

Kind regards... dsmavis

all iot websites have some sort of limitations. either on the rate or the amount of data uploaded.
id like to store values every 2-15min 24/7 365days a year

ps. xively has closed down the sign ups

all iot websites have some sort of limitations. either on the rate or the amount of data uploaded.
id like to store values every 2-15min 24/7 365days a year

I was sending three temperatures to xively at ten second intervals for a couple of years and other IoT services are just as capable.

2bytes every 2 minutes = 60 bytes an hour.

24*365 *60 bytes =525600 bytes a year.

Yep. About half a megabyte.

There should be plenty of online ftp/mysql/database servers that will give you that.

Xively signups closed down? Are you sure?

I found this on their site:

Doesn't this work?

Like I said, I have had my free account for 2+ years. It was Pachube when I signed up, then Cosm. Now it is Xively.

Anyway, I just login because I am already a member so I don't know if the signups have been disabled, but I poked around a bit and did find the signup link above.

yep xively has closed down the new accounts. even id you sign up you get the message.
i found grovestreams. 5MB/month seems promising

Okay. Thanks for the info. I'm sure there are other sites that could work for you and it seems you may have aleady found one.