[chokapick]

Anyone knows approximately what will be the power consumption of an RX unit powered by batteries with just the DHT22 sensor?

I would like to estimate the consumption of the circuit in order to decide if I'll need to find a better power solution or the batteries will be enough.

[werk_ag]

Anyone knows approximately what will be the power consumption of an RX unit powered by batteries with just the DHT22 sensor?

I would like to estimate the consumption of the circuit in order to decide if I'll need to find a better power solution or the batteries will be enough.

Do you mean RX unit or TX unit?
Anyway, only the Arduino Nano have a consumption of around 35mA, which not makes it very suitable to be powered by batteries, unless you are thinking in large capacity batteries.
If your question is about the TX unit with just the DHT22 sensor, you may expect an average consumption of 80 to 90 mA.

[chokapick]

Upsss... I was talking about TX unit, not RX.

In the meanwhile I remember that I have an USB adapter that shows the power consumption. It's a bit late today, but tomorrow I'll check that and post the results.

[werk_ag]

Can you please give me some info about your USB device, that gives you indication of current consumption from the equipment connected via the device?
It can be very useful!

[chokapick]

What I use is this:
http://www.ebay.co.uk/sch/i.html?_from=R...r&_sacat=0

But as you can see in the attached picture this model doesn't have enough resolution for this propose.

[werk_ag]

Thanks for that info. Anyway it's a interesting device.