Posted by mudz Apr 7, 2015
AIM: To establish a connection between IoT starter Kit and Internet enabled Modem via AirGrid Modules.
Requirements: ARM mbed IoT Starter Kit, 2 AirGrid M5-HP Modules, 4 Ethernet Cables, 2 PoE adapters, Internet enabled Modem.
FRDM-K64F Starter Kit connected with AP(AirGrid Module) Station(AirGrid Module) connected to office Modem(Internet) or pc
Introduction:
The Idea is to test the ARM mbed IoT starter Kit for Home automation. It is just a test not full implementation of this kit for home automation. In this Experiment we are going to connect Starter Kit(at home) to the Modem(Internet at workplace) with the help of two AirGrid modules which create a Wireless Lan link between Home and office. If this experiment is successful we know that we can replace the modem with our PC (at workplace) to give control commands over Wireless link to Starter Kit for Home automation or smart home like features.
Tasks to perform:
1. Configure AirGrid M5-HP modules to Work as Wireless link.
2. Connect ARM mbed IoT starter Kit with AirGrid M5-HP module(AP).
3. Connect Station AirGrid module to Internet(modem)
Task 1:
Aim: To establish a Wireless link between two AirGrid Modules.
This is done by configuring one of the AirGrid module to work as a Station and the other one as Access Point. How to do it? I will Explain it step by step but first lets get familiar with the equipments we will be using for this experiment.
1. AirGrid M5-HP Module 2. Power over Ethernet (PoE)
1. AirGrid M5-HP : These modules provides a Wireless Lan Links for long distance data transmission with the help of Antenna. These Modules generally works on 5GHz (Unlicensed Band Radio) frequency range. for more on these moduels visit: https://www.ubnt.com/airmax/airgridm/
These modules does not work right away after opening them from the box. We need to configure these modules to work and that too as per our requirements i.e. how we want to use them. For now, we just want to create a wireless link between our home and Office. So we need to make one module to work as Station (at Internet side; office) and Access point (at Kit side: Home).
2. PoE: Power over Ethernet adapters provide power to these AirGrid modules. These PoE's are highly reliable and are generally used for continous working conditions. Output voltage is in range of : DC 24v, 0.5A.
If we take a closer look at these PoE, we find two Ethenet ports mentioned as POE & LAN written on its surface. We connect Airgrid Module to POE via Ethernet cable. This POE provides the required power to drive the AirGrid Modules. To establish a connection between PC/Modem to this Airgrid Module we connect Ethernet cable to this(PoE's) LAN port.
Powering the AirGrid Module:
Connect POE to the AirGRid Module via ethernet cable and connect power cord to the PoE adapter. Switch on the PoE adapter.
3. Airgrid Module connected to POE via ethernet Cable
Configure the AirGrid Modules:
We need to configure each AirGrid module one by one. Lets first connec one of the module and configure it as Station.
Configuring Airgrid Module as STATION:-
1. We already have supplied power to the Airgrid module, now connect the ethernet cable coming out of the LAN port of the PoE adapter(shown in above picture 3.) to the PC/Laptop.
2. Now the pc is connected to AirGrid module and the connection is shown as limited connection on pc.
3. To access the AirGrid module we need to login it by its Default IP Address: 192.168.1.20. Lets try opening in internet Explorer.
4. There was a problem opening this default IP address. Lets try one more time but this time we configure our ethernet adaptor on our computer with IP Address: 192.168.1.41 & subnet mask: 255.255.255.0.
5. Lets try to login again. This time it shows certificate error and asks whether to continue to this site or not. Click continue and a Login page is shown over the browser.
6. Login with default username and password: ubnt. Choose your country, accept Terms & conditions and hit login.
7. A welcome screen as shown in Image below will appear. We now know that this module is already configured as Station(by looking at the Wireless Mode in MAIN tab). We still need to configure it with our specifications. Lets move to WIRELESS Tab.
8. Enable WDS. Write MAC address(written adjacent to the ethernet port) of the other AirGrid Module. Enable Frequency Scan List and choose 5835 MHz.
9. Important Step: Lower Down the Output Power near to 0 dBm. I have done this as my distance is very close. Sometimes they blow up if the power set is 25dBm. So for closer range it should be as low as possible.
10. Hit change and Apply settings.
11. Select Network Tab, change IP address to 192.168.1.21. Hit change and Apply. Thats it.
Now one of the Module is configured as Station:-
1. Ethernet cable connected to pc 2. Problem in Accessing default IP address of AirGrid Module
3. Configuring ethernet adaptor on computer 4. validate settings and selec Ok, network diagnostic will run automatically
5. Trying default IP again, shows Certificate Error, click Continue & add certificate in exception List. 6. Login page
7. Not configured Airgrid Module MAIN page 8. MAIN page showing No AP information
Configuring Module to Station:
9. Select Wireless Mode 10. Enable WDS, insert MAC Address of other AirGrid Module
11. Select Frequency from list 12. Output Power to 0dBm
13. Change and Apply Settings
Now changing the IP address of Station Module:
14. NETWORK page, change IP address 15. Click change and Apply
16. New IP address of Station Module, login with default Username & password 17. AirGrid Mosule configured as Station WDS
Configuring second Airgrid Module as Access Point(AP):-
1. Power up the second AirGrid module with PoE and connect the ethernet cable coming out of PoE adapter to PC.
2. Now enter the default IP address in browser: 192.168.1.20. Enter the Login details same as previous.
3. Select WIRELESS tab and choose Access Point in Wireless mode. Now the page will change few settings.
4. Enable WDS & Frequency list. Choose 5835 MHz from frequency list tab.
5. Change Output power to 0 dBm. Hit change and Apply. That's it. We need not to change NETWORK settings.
Now the other module is configured as AP(Access Point):-
18. Configuring AirGrid Module for Access Point 19. Keep NETWORK settings as it is
20. AirGrid Module configured as AP
Now, Place both the Modules in Line of sight but little far from each other:
21. Station and AP connected, LED's shows the signal strength 22. Station and AP connected, details are shown by airOS
Now we have established a Wireless connection between both the Modules, Now, we can use various test tools on airOS.
23. Different tools used to test, debug AirGrid Modules
Align Antenna:
This is used to alignment of the two AirGrid modules when they are installed on site. For better data transmission Line of Sight of two modules must be clear. We use this tool to align both the modules to get maximum data transfer with low loss and low Output Transmission power.
Align Antenna tool showing signal & noise levels Changed position of modules shows change in these readings
Site Survey:
This tool is used to Search all the wireless networks in range on all supported channels. As we have already set it for 5835 MHz it will scan for all the wireless networks in range with this frequency.
Station Module Site Survey scanning results showing AP module
Discovery:
The Device Discovery tool searches for all Ubiquiti devices on the network.
Discovery tool showing both the discovered modules with their respective IP Address
Ping:
Ping is the most common tool we use in networking. We use it to discover & find latency of the device on the network. With this tool we can ping other devices on the network directly from the device. The Ping tool uses ICMP packets to check the preliminary link quality and packet latency estimation between two network devices.
We know,
IP Address of our laptop: 192.168.1.41
IP Address of Station Module: 192.168.1.21
IP Address of AP Module: 192.168.1.20
Station side Ping tool showing AP and Laptop IP addresses to ping. Result when AP IP address is selected to ping with mentioned packets.
Traceroute:
The Traceroute tool traces the hops from the device to a specified outgoing IP address. This tool is used to find the route taken by ICMP packets across the network to the destination host.
Station side results when AP address is selected
Speed Test:
This tool is used to test the connection speed between two modules.
Station module speed test tool located two devices IP Addresses on network Speed test between Station and AP
Results of Speed test between Station and AP modules
All these tests shows we have establish a Wireless link between two AirGrid Modules Successfully and these are working with proper data transmission rate & speed.
Task 1:Complete.
Task 2: Connect ARM mbed IoT starter Kit with AirGrid M5-HP module(AP).
Disconnect both the ethernet cable from pc side, which are used to establish connection between Airgrid modules and pc/laptop. Now, we are going to install these Airgrid modules on poles and create Home to office like conditions by placing them far from each other. Connect one of the ethernet cable coming out of the PoE adapter of AP AirGrid Module to the ethernet port on the Starter Kit.
AP connected to ARM mbed IoT Starter Kit
Task 2: Complete.
Task 3: Connect Station AirGrid module to Internet(modem).
We left with one ethernet cable coming out of PoE adapter of Station Airgrid Module. We are going to connect this cable to the Modem which has Internet Access to it.
Task 3: Complete.
Final Steps & Working:
What we have done till now:
We have connected ARM mbed Iot Starter kit to AP module and Station module to Modem(Internet). Indirectly we can say, (If we consider Station and AP modules Wireless link as a single LAN cable link) we have connected Internet to the IoT starter Kit. So, Starter Kit running demo code will try to connect to IBM cloud and when the connection is established(Green LED will glow) it will send its sensors data to IBM Site over the internet. This means if the whole setup is working we should get our Startkit sensors reading on the IBM site. Let's see what happens when we power on both the modules PoE and Modem. For this experiment I have supplied power to Starter Kit with the help of a smartphone charger to show that all the readings on laptop are coming over the internet not from USB cable.
Starter Kit(at home) trying to connect to Internet(at Office) Starter Kit(Home) connected to Internet(Office) via AirGrid Modules
