Remote Accessing your home network using smart phone and 5€ Linux H/W

In my quest for finding a cheapest off-the-shelf linux h/w, I came across this 5Euro device capable of running open-source linux OS(openwrt). I was delighted to see this tiny little device(A5-V11-router) consuming just around 0.3Watts - this is a perfect piece of h/w for IoT application.

Here are some interesting facts about this little device(A5-V11-router).
1)100Mbit Ethernet port
2)IEEE802.1b/g/n wifi interface
2)An usb port for attaching peripheral device
4)360Mhz Mips CPU(Ralink RT5350)
5)32Mb SDRAM
6)4Mb flash.
7)red and blue LED for showing different status.

It was intended to be used as an internet-hotspot  in combination with usb-3g-dongle and simcard. But, for my use, i have overwritten OEM fmw with my own customized openwrt(a5v11-xmpp) image which can be downloaded from here.

Q: what is the purpose of customized a5v11-xmpp image?
Ans: in this image, I have stripped down most of the router/wifi functionality to accomodate an xmpp-chat-client-daemon(lib-gloox based) to act as a chat-bot. Xmpp makes it easy to access your home network without tweaking your home router settings(e.g:port-opening/NAT etc). You dont need to expose any ports of your home-broadband-router to the internet.

Overwrite OEM firmware of a5-v11-router with a5v11-xmpp image and keep this little piece connected to your home internet so that you can "chat" with your h/w even when you are outside of home network.


Setup Instructions:

Step-1: Xmpp master/slave account creation.
As explained here, you need to prepare two xmpp/jabber accounts on your favorite jabber-server. and let these two accounts be "friends" so that xmpp-server can pass the messages between these two accounts.

Step-2: connect CAT-5/6 cable between your pc and a5-v11-router and power ON the router.

Step -3: Overwrite Stock Firmware with openwrt based a5v11-xmpp-image
On openwrt wiki there are instructions about how to overwrite stock firmware with openwrt-firmware. For overwriting the stock firmware with a5v11-xmpp-image, you can follow a step-by-step guide as detailed here in my other blog.

Step-5: Connect a5-v11-router to your home router's network(internet).

Step-6: login  to host "my-a5v11" using ssh/putty (user: root | pw: brb0x)

Step-7: prepare login details (This step is redundant as it is already explained in step-3)
echo "user: test-slave-account@xabber.de" >/etc/xmproxy/xmpp-login.txt; echo "pw: chatbotpw">>/etc/xmproxy/xmpp-login.txt ; reboot
Note: in above command, replace test-slave-account details with your own user/pw. (also use passwd command to change the default root password(brb0x) to your own)

Step-8: prepare your smart phone with xabber app and login using  test-master-account username and password.

Step-9: you will see that your a5-v11-router is online on your smart-phone's xabber app.

Step-10: type "help" and send the message to a5-v11-router, you will get the reply with list of available commands.


Q: Ok, what now? i have this tiny little device sitting next to my home router consuming 0.3w, what next? what can i do with it? can you give some examples?

Ans: here are some commands that makes this device useful.
1)From your smart-phone(no matter where u r in the word, as long as your phone is on internet) send "publicip" chat message and you get the response from chat-bot showing public-ip of your home router, this helps you to be independent of dynamic-dns setup, you can always see public-ip using xabber app.

2)connect i2c-tiny-usb (as shown in the picture below) to generate i2c from USB port of a5-v11-router, with i2c you can control/read many pheripheral chips ex: temp/humidity sensor, power sensor, gpio relay-control(use your imagination for home automation with i2c).
send  "shellcmd i2cdetect -r -y 0" and wait for "return=Success" message, and then read the output of last triggered shell command using "shellcmdresp" to see what i2c devices were detected.
ex: use "shellcmd i2cset -f -y 1 0x3c 0x00 0xff b" to make all pins of PCF8574 high.

3)Control sonoff wifi relays having tasmota firmware. ex: In your home network, if there is a sonoff relay at ip 192.168.1.10, send the following commands to chat-bot for controlling the relay(chat-bot uses http GET commands to control sonoff relays).
                a)"sonoff 192.168.1.10 on"        - switches ON the relay.
                b)"sonoff 192.168.1.10 off"       - switches OFF the relay.

                c)"sonoff 192.168.1.10 toggle"  - toggles the relay.
                d)"sonoff 192.168.1.10"             - reads the current state of relay.
Note: Incase if  sonoff relay has a hostname, replace the ip with hostname in the example above.

4)on your network if there are linux pc's, you can trigger remote commands via sshpass of the chat-bot. Here is an example..
                a)"shellcmd sshpass -praspberry ssh -y pi@raspi-ip  sudo reboot" would reboot raspi.
                b)"shellcmd sshpass -praspberry ssh -y pi@raspi-ip  sudo poweroff" would switch off raspi.

                c)"shellcmd sshpass -praspberry ssh -y pi@raspi-ip  omxplay /tmp/video.mp4" would start playing mp4 video.

5)send etherwake command to turn on a PC which was already in WoL mode, ex:

                 a)"shellcmd etherwake 00:00:DE:AD:BE:EF" (replace the MAC id with actual one)

watch-out this blog for for more use cases...

Q: I dont trust your ready to use image, I need to know the details, where are the sources? how can i create the image myself?
Ans: Here is the link to sources and build instruction so that you can create your own trusted image.

RBox - A Lightweight Linux system for IoT

Update(18.11.2016): Raspi image provided here works only on Raspberry pi B+ 

RBox is an acronym for RemoteBox which is a light weight linux system specifically designed to address the connectivity challenges of IoT devices on public internet. Some of the key features of Rbox are as listed below.

1. Runs on low cost opensource h/w like Raspberry Pi B+, BeagleboneBlack and BeagleboneGreen.
2. Less than 20Mb of update-binary image for Raspi and less than 10Mb of update-binary for beaglebone.
3. Provides an easy way of online update to latest Rbox version from a remote location and without having to remove SDCard, It uses a dual-boot mechanism for fail-safe linux upgrade against power-outage or network-failure.
4. Keeps your Raspi or Beaglebone always accessible via xmpp chat server on public internet.
5. Xmpp chat messages will allow you to remotely read/write GPIO pins of Raspi or Beaglebone.
6. Provides basic set of commands to monitor the health status of Rbox.
7. Lets you connect Huawei E173 GSM modem to usb port of raspi or beagle, and provides basic set of sim management commands like read-sms,send-sms, delete-sms, dial-ussd-code and voice-dialling(for the moment its dialing only, no GSM-to-voip bridging).
8. Open source project hosted on Gighub

What are the Applications of RBox?

Although RBox is in early stage of the development, there could be many use cases where it can be deployed for remote asset management. As of now, I came across following use cases where RBox can be useful.

1. Home Automation
2. Remotely Deployed GSM SIM Management.

How to deploy RBox on Raspberry Pi B or B+?

1. First and foremost is to have two xmpp login accounts on publicly available jabber servers(So far RBox has been tested with jabber.de/xabber.de and ubuntu-jabber.de). Follow my previous Post on how to create master and slave xmpp accounts(ensure that master/slave accounts have authorized each other to send/receive messages).
2. Download the initial SDCard Image from here.
3. Unzip the downloaded xz image using 7zip or your favorite decompression tool.
4. Write the unzipped binary image to Sdcard using Win32DiskImager. 
5. After writing the image to SDCard, remove and re-insert the card on your PC. Your PC will detect a new drive as "boot" where raspi's kernel and boot images are listed.
6. In this "boot" drive, create a new file called xmpp-login.txt and copy this text. After copy, edit this file and replace sample user and password with actual username and password of your slave-device which you created in Step-1.
7. Remove the SDCard from PC, and insert it into Raspberry Pi, connect network cable and power it ON(ensure that your LAN has internet connectivity).
8. On your android phone, open xabber app and login using master's username and password which you created in Step-1.
9. If everything goes well, raspi will show up as online on your xabber client.
10. Send a "Help" to your raspi-slave, it will reply with list of available commands.
11. Send "Sysupdate;reboot" and wait for raspi to update to latest RBox image, after update, it will reboot and be back online again with latest RBox version. Here is the detailed information on all available commands.

Please note that RBox is in its initial development phase, so far i am a lone contributor to this project, hopefully it will get better as more contributors join. Let me know in comments section if you are facing any problems.

In the coming days, I would be posting information on "How to deploy RBox for Beagleboneblack/green".