DS18B20 temperature sensor and power consumption


I'm in the process of building a wireless and solar Arduino based temperature sensor.

Obviously power consumption is important because it's going to (hopefully) be reliant on solar/battery power.

Currently I'm using Bluetooth for the wireless communication but this will more than likely change to nRF24L01+ when the parts arrive.

Power is provided by 4xAA NiMH batteries through the regulated 5V pin and I get about 48 hours in total.

I've tried with both the Pro Mini and Nano boards and power consumption is identical. I will probably go to a barebones/breadboard setup with an atmega328p chip with a minimum amount of components to reduce the consumption.

I'm using a premade DS18B20 module (this one) - I will change this for a bare sensor and resistor for the final build.

My main question is though: When idle (with BT connected) the consumption is 43.3mA. When the temperature is actually being read from the sensor the consumption drops to ~30mA. Temperature is read every 5 seconds.

Can someone explain this drop in consumption? Am I right in thinking that if I increase the frequency of the temperature being read (constant loop maybe) that my overall consumption will decrease?


It's hard to explain the drop in consumption, without sketch/schematic.

Looking at your temperature-sensor module, I do notice a led that you don't really need.

Nick Gammon has a nice tutorial on how to save energy on the controller side b.t.w. http://gammon.com.au/power

I'll post the sketch this evening (I'm in the UK).

Yeah, definitely going to get rid of that sensor board in favour of sensor on its own. Every mA helps!

Spotted that tutorial a while back but lost it so thanks for the link, definitely to implement some of the power-saving tricks.