DIFF ADVICE - DHT22 sensor using nRF24L01+ and 2 nano’s - Battery power options

Projects General Guidance
1

ADVICE CHANGE
Post #3
Didnt create a new thread, thought it’d be better to remain in one thread.

Hi

I’ve just build a temp and humidity unit with a rgb LED and lcd display, with the help of you guys here on other threads.

The original purpose of this was to monitor the temp in my sons room. Which then I realised the display etc would not be needed, so thats going to be another project, being a weather station.

My next plan is to have the dht22 in the room, with the lcd display elsewhere on another unit. How could this be done, the only thing I’ve found is an ESP8266, which I need to research more into.

I’ve only used an Uno so far but I was thinking of getting a Nano to encase with the lcd display and power via battery.

Is the ESP8266 the only option, any other recommendations? I’ve already got the ESP8266 01

Thank you

2

If you want to just send the temperature and humidity directly to another Arduino for display (no WiFi needed) I would suggest a rf24 radio connected to your choice of Arduino on each end. See Robin2's simple rf24 tutorial.

3

groundFungus:
If you want to just send the temperature and humidity directly to another Arduino for display (no WiFi needed) I would suggest a rf24 radio connected to your choice of Arduino on each end. See Robin2's simple rf24 tutorial.

Ah I see. Not come across that before. Will have a read. Thank you.

Any other methods?

4

Advice Change

With the advice above, I plan to have two separate units, one with a Nano, DHT22 and a nRF24L01+ Transmitter.

The second unit with a Nano and a nRF24L01+ as the receiver.

Looking at data sheets its appears the current consumption would be;

Transmitter 11.3mA at 0dB
Receiver 13.5mA at 2Mbps
DHT 1.5mA measuring
50uA at standby

I’m not sure what the consumption of a Nano is as of yet, as I dont own one yet.

I’ll only use it in the evening to monitor my sons room and then will switch it off through the day. Well thats the plan.

I’d planned to use two AA batteries per unit by using a DC-DC converter, giving a 5V output. Then the other conponents will be powered by 3.3V. I know the best way would be to build, trail and error but I need to order the parts.

Would AA batteries work long term or would the better option be to use 18560 batteries? Aside from the recharging capabilities, just considering power/current drainage.

Apologies I’m asking a lot here.

5

If you want to minimize consumption don't use a Nano, just make up standalone Atmega 328 on a piece of stripboard. See this Arduino Breadboard tutorial. If you use the internal 8MHz oscillator very few external parts are needed

See also Nick Gammon's power saving tutorial

...R

6

Robin2:
If you want to minimize consumption don't use a Nano, just make up standalone Atmega 328 on a piece of stripboard. See this Arduino Breadboard tutorial. If you use the internal 8MHz oscillator very few external parts are needed

See also Nick Gammon's power saving tutorial

...R

Thanks for the links. The N. Gammon one looks very informative and indepth. I’ll have a read of both.

I had considered that but just wanted an excuse to buy some Nano boards to be honest ha.

I’ll have a look down that road, an individual IC.

Also thanks for the article regarding the nRF24L01+. I’ll ise the tutorial when testing the unit.