Not sure what happened to the links in the mysensor store but here is the link to the sound sensor you need, make sure it is the one that has 4 pins, with analog output as an option.

http://www.ebay.com/itm/1pc-New-Analog-Sound-Sensor-Board-Microphone-MIC-Controller-For-Arduino/300951969384?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D24143%26meid%3D8558634634764594554%26pid%3D100005%26prg%3D10240%26rk%3D2%26rkt%3D6%26sd%3D251565637147&rt=nc

Here's how I'm charting the data collected,

http://forum.mysensors.org/topic/61/mysensors-electricimp-xively

Electric Imp can easily be replaced with arduino with connection to web via ethernet or wifi.

You may want to have a look at this for some ideas or inspiration, it has pro mini and nrf24l01 connections and some of the features you want.

https://oshpark.com/shared_projects/pRJiKWxV

$18 for 3 boards, pretty pricey, considering the brains of the system only costs $3 and the nrf only $1.

Check this out,
http://www.instructables.com/id/safe-and-simple-AC-PWM-Dimmer-for-arduino-Raspberr/all/?lang=pt

You may want to disconnect everything and just leave the power supply and arduino, then measure the RAW pin and VCC pin, RAW should be anything above 5V, VCC should read 5V for the 5V version and 3.3V for the 3.3V version. Any other readings on VCC suggest that your regulator on the arduino is faulty.

Could try reducing the baud rate between gateway and vera. I had trouble communicating with the serial gateway at the highest speed (only 1 way communication), reducing to 9600 solved it.

Your pro mini is a 3.3V version or 5V version. If your VCC pin measures a bit over 3V, looks like you are having a 3.3V version.

Here are the results in Xively.
You will noticed I used the Node ID and Child ID as the Channel name.

MySensors is such an awesome development! Thank you guys, keep up the wonderful work.

The objective for my first MySensors project was very simple, connect a wireless network of sensors and store the data in the cloud.
This project involves the following,

1. Several sensors (temperature, humidity, pressure, light, power)
2. Gateway
3. Electric Imp (for wireless connection to internet and Xively)
4. Xively (for logging the sensor data)

I do not own a Vera to act as the controller, though I own a Raspberry Pi, seems like there will be alot more development needed for this hardware. Hence, I settled without using a controller for now. Since I just wanted to log sensor data (no actuation for now).

Modifications needed to MySensors code:

1. Sensors
   • Since there is no controller to provide the sensor ID, i had to force the ID by entering it in the gw.begin() statement ie. gw.begin(10) for ID 10
2. Gateway
   • No modicifations needed here
3. Electric Imp (receive serial comm from gateway and post to Xively)
   • refer to https://xively.com/dev/tutorials/electric_imp/
   • Had to modify the above code to only process serial messages that contain Message Type = 1 (Set Variable)

Feel free to post your interest and I will be more then willing to share more of my experience.

also uncomment #define DEBUG in config.h to see more debug messages...

You did not mention any Controller in your setup, I'm assuming you only have the gateway + sensors up (without Controller, ie. Vera)?
First of all if you did not change any part of the code, it will not work, because the sensors always sends a request to the gateway to request for an ID, and the gateway will send request to the controller for an available ID. If no respond from Controller everything stops there. However you can bypass the ID request by just forcing an ID on the sensor code by putting the id in the gw.begin() call, ie. gw.begin(10) for ID 10.

If you need SMS/GPRS the following boards would be great,

http://imall.iteadstudio.com/development-platform/arduino/arduino-compatible-mainboard/im130514001.html
http://imall.iteadstudio.com/development-platform/arduino/arduino-compatible-mainboard/im120411004.html

Both also have the nrf24l01 adapter builtin for you MySensors network.

Battery Options (for sensors, regularly sleeping)
-1 alkaline battery + Step-up Power Converter to 3.3V
-2 alkaline batteries in series or button cell lithium battery like CR2032 (3V)
-LiPo battery (3.7V)
-3 NiMh batteries in series (3.6V)

Non-Battery Options (for gateways and repeaters, always on)
-USB Phone charger + Step-down Power Converter to 3.3V

Awesome! Thanks!

@NotYetRated Biggest difference I see is the USB FTDI onboard, good if your are connecting to a vera or something needing the comms. If it is going to be purely a sensor node, I don't see why u need this. The pro mini has 5v and 3.3v variations, or look for switchable ones, pro mini enhancements. If you are frequently reprogramming it, then easier with the nano, I'm fine using a separate ftdi board for programming purposes.

As in RF24_CHANNEL in the config.h? So this means if i compile and upload all my sensors, repeaters and gateways, all will automatically be on the channel configured in config.h?

This is an awesome development for arduino + nrf24l01. What I would like to know is what happens when there are more then 1 gateways within the radio range, ie. if your neighbour has also setup a similar network. Is there some kind of unique addressing on the gateway or sensors to be configured?

Here are some alternative arduino boards that can be used for the wonderful pairing of arduino + nrf24l01.

For sensor (arduino+nrf24l01 header) - Sensor Node by Elecrow,
http://www.elecrow.com/wiki/index.php?title=Sensor_Node_V1.2_(ATmega_328)

For gateway (arduino+ethernet+nrf24l01 header) - IBOARD by Iteadstudio,
http://imall.iteadstudio.com/development-platform/arduino/arduino-compatible-mainboard/im120410001.html

Please add any other hardware options you find and that make this project even simpler to implement.