Help choosing the right wireless module

[paimpozhil]

Hi All,

I'm very basic at electronics and wireless.

What I'm trying to do is , get my battery/solar PV voltages and current monitored remotely from another location on my home.

I've chosen the Raspberry Pi to store/make the data available all over the home/internet with Ethernet connection.

NRF24L01+ module with printed antenna is used to communicate the Ardino and the Raspberry pi which acts as a hub.

I went with the NRF24 at first place because they are very cheap than lets say xbee , at just 2$ it was great and cheap to learn .

So far I've succeeded passing the data from Arduino back to raspberry Pi however it works only with small distance (4M-5M) passing 1 wall or so.
I need to be able to pass this data through almost 3-4 walls of concrete and with distance of roughly 10-12M or less.

There is 2 other vareity of the NRF24 circuits available. one with a only SMA antenna.. and another with PA/LNA and SMA
http://www.ebay.com/itm/NRF24L01-PA-LNA-SMA-Antenna-Wireless-Transceiver-communication-module-2-4G-1100m-/310673096920?pt=LH_DefaultDomain_0&hash=item48558f40d8

costs about 12$

http://www.ebay.com/itm/Arduino-2-4G-NRF24L01-Wireless-Transceiver-Module-SMA-Antenna-Microcontroll-/200932672566?pt=LH_DefaultDomain_0&hash=item2ec8854436
costs about 7$


I want to know if PA/LNA is worth the extra 5$ or would the SMA antenna alone do the job for my requirement?

Is bigger antenna version required at both the ends or would it suffice to have the HUB use the wireless chip with bigger antenna and leave the sensors with the basic  NRF24L01+ without external antenna?

Let me know if this chip will do the job , or if i should consider other alternatives like xbee or RF12M

[gr0b]

Hello,

I use the nRF24l01+ radios too. For my nodes I just use the cheap $1 versions (same as you) but for the the main base station I use a version with PA/LNA + ext ant(~2dBi).
http://www.aliexpress.com/item/Free-Shipping-nRF24L01-PA-LNA-wireless-communication-modules-with-antenna-2-4GHz-2Mbps-1000m/709420583.html
about $8 each.
As the higher powered modules use more power I only use them on the base station and not on the battery powered nodes, This works fine for me out of box giving range of over 30m with 3 brick walls and a stainless steel kitchen between. 

One little problem with the module is that it has a SMA connector not a RP-SMA connector but it is not too hard to get an adapter for or replace it.
Most 802.11BGN(WiFi) antennas are RP-SMA and because 802.11BGN is also 2.4Ghz you can use Wifi antennas to boost your range, on one of my modules I replaced the ~2dBi pigtail antenna with a cheap 12dBi wifi antenna( the smaller antenna worked just fine I just did this because I could)   

To boost your range you can also change you data rate. I use 2Mb as battery is more important then range for me currently but if you drop your range down to 250Kb you should get much better range(~30m) just using the cheap modules. The RF24 library also lets you adjust the transmit power, make sure you have it set to max.     

[ardman26]

Hello Friends,
I am working on a project of Home Automation System, which includes wireless sensor nodes and a central device.
I am looking for a cheap RF transceiver  for transmitting and receiving the signals from sensor nodes.
So I have to receive the data from multiple nodes. So which RF module is fit for the purpose.The module must be compatible with UNO board

I have to communicate with few bits of data.
For multiply receiving the data which one is better multiplexing or multiple  channel receiver.
Please help. Its urgent.

[flyboy]

I'm also getting interested in wireless.  Does anyone in the community have some sort of chart or side-by-side comparison with some strengths/weaknesses for beginners such as myself?  I've been trying to do some research, but I'm still having some difficulty in how to choose a suitable solution.

[Arrch]

Does anyone in the community have some sort of chart or side-by-side comparison with some strengths/weaknesses for beginners such as myself?  I've been trying to do some research, but I'm still having some difficulty in how to choose a suitable solution.

SparkFun has a comparison tutorial up somewhere on their site.