Hi,
Looking into creating a few battery powered temperature sensors for my house. Looks like Xbee or similar (HC-05) from ebay costs about 1 GBP incl. shipping can be a good alternative.
What I'm struggling to understand is, can the HC-05 with a temperature sensor (TMP-36) work independently if connected to a battery to send temperature readings every 10-60 minutes or similar. Or do you need an Arduino or similar with each of the HC-05 to control time and tell the HC-05 to send the data..
I feel that I am misunderstanding things here.. but what Im trying to find out is. What is the best, cheapest, wireless, battery powered temperature sensor that I can create.
The HC-05 is simply a serial transmission device and you need an arduino to read the sensor and send the signal. If you use bluetooth, I think it would be better to use an HM-10.
I don't know anything about the ESP8266, but I think it might be more suitable as I understand it can be used without an Arduino.
The NRF24 is as dumb as bluetooth, but it is more suitable for arduino networking.
Nick_Pyner:
The HC-05 is simply a serial transmission device and you need an arduino to read the sensor and send the signal. If you use bluetooth, I think it would be better to use an HM-10.
I don't know anything about the ESP8266, but I think it might be more suitable as I understand it can be used without an Arduino.
The NRF24 is as dumb as bluetooth, but it is more suitable for arduino networking.
To create what I'm aiming at would require something that require very little energy, so I don't have to change the battery every week. Should aim at 1 yr + for battery life.
Wifi isn't known for being especially energy efficient, so a bluetooth type of wireless communication is probably required...
a bluetooth type of wireless communication is probably required...
Most wireless weather sensors use dirt cheap and simple 433 MHz modules or similar, and run for a couple of years on a single AA battery.
Here is an example of an extremely low power remote sensor project that runs entirely on sunlight. There is lots of other power saving info on that site.
It is easiest to simply buy the temperature sensors and use an Arduino to decode the transmissions. See this example: Reverse Engineer Wireless Temperature / Humidity / Rain Sensors — Part 1 « RAYSHOBBY.NET
jremington:
Most wireless weather sensors use dirt cheap and simple 433 MHz modules or similar, and run for a couple of years on a single AA battery.
Here is an example of an extremely low power remote sensor project that runs entirely on sunlight. There is lots of other power saving info on that site.
Great, that was perfect 
I liked the idea of the 433 MHz Nordic Semiconductor modules. I just ordered 10 (link) - anything else that I will need? in addition a kind of ATmega (or Arduino board)? and a battery holder? + capacitors and resistors etc.
anything else that I will need?
Study the link to the solar powered Arduino. Everything is in there. Lots of other useful stuff on that site, as well.