ESP8266 Community Forum

- Tue Aug 04, 2015 3:53 pm #25034 Hi,

I'm in the process of building a set of temperature sensors for different rooms in my home. I was wondering if anyone has any recommendations as to how frequently I should publish the room temperature? I was thinking about every 5 to 15 minutes should be adequate.

My goal is to collect individual room temperature data over a long period of time and analyze the data.

Thanks for your help!

- Wed Aug 05, 2015 3:02 am #25063 Once an hour is sufficient for a long time ( one week, month )
Look at similar issue: http://silesia-eco.ue.wroc.pl/Home/EcoHCentralH

- Wed Aug 05, 2015 9:58 am #25088 I'm collecting every 1 minute, logging on 5 minute steps using RRD. I keep 1 year of data at 5 minute resolution, 5 years of data at 1 hour resolution, and 15 years of data at 1 hour resolution.

Disk space is cheap these days. By taking advantage of RRDs capabilities to handle multiple samples per sample period and consolidate those accordingly, I am able to reduce the number of sample periods for which data is not collected.

In my tests, a 3.7v 2500mah LiPo battery with a 6"x6" solar cell is able to be fully charged by about 11 AM after running all night doing these collections. (Summer time). Probably about 2 PM during winter, but I have no winter time experience as yet.

In my environment it's about 4-8 seconds from Boot through collection, WiFi connection, and data posted to web server, then go back to deep sleep for 55 seconds.

I'm using the ESP8266 with Dallas/Maxim OneWire DS18B20 temperature probes.

I'm also using Particle Photon boards with DHT-22 Temperature/Humidity probes. I plan to add DHT-22 support to my ESP software and add OneWire support to my Photon software.

Both use the same CGI script by posting a simple query string.

- Wed Aug 05, 2015 4:36 pm #25121 Great feedback! I really appreciate it!

I plan on using the ESP8266-01 and DHT22. Still figuring out power. All of the sensors are in the home but I'm not sure I want to take up a power outlet for each room, so I'm considering using a LiPo battery (I have a few expired cell phones I've been hacking the batteries out of!)

It sounds like a good overall design is to also load a Rasberry Pi with Mosquito MQTT as a broker and then Node-RED to orchestrate the published data over to storage (perhaps CouchDB or MongoDB). After that it is just a matter of layering analytics on top.