Solar Relay v2
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Transcript of Solar Relay v2
Page | 1
Solar 3G internet repeater Guide
This is version 2 This relay station is my only source of internet with nothing to fall back to, ensuring
uptime, performance and the lifespan of the station is very important to me. This
version has the updates I’ve made to the relay since posting my previous guide on
Scribd.
I learnt a lot during the build and a lot more in the half a year or so it was running.
This updated guide:
Incorporates a whack of new features over my previous station
Simplified with less parts
Redesigned with a large station lifespan in mind
What is a solar internet repeater? It is a small, remotely placed station powered by solar to receive internet from 3G/4G
where you have reception and relay it back to your house where you don’t.
If you cannot get any form of internet where you live a relay may be a good option
to get a fast and reliable internet connection.
What’s in this guide? This guide has all the steps you will need to take to make a relay station of your own
from finding the perfect spot to put it to using the internet.
It should be easy to substitute any of the hardware I use with any other compatible
hardware you like. This guide was written with the following in mind:
My ISP is Telstra BigPond connecting via the BigPond branded Sierra Wireless
AirCard 312U
All hardware configuration using a computer is done using Windows 7
Relay is for 3G as I don’t have 4G in my area – switch of modem/antenna
would enable this in the future. Any reception stuff is mainly for 3G
Based my exact needs and is suited to my location
When I decided to ditch my really crappy satellite connection and escape the
extortionate fees, I didn’t have a guide to go off and surprisingly, there isn’t much
information on the internet in one central place.
Page | 2
Choosing a site Finding the perfect spot
Kind of obvious but… The first thing you need to do is make sure you even get reception in your area. To
start with, use the official BigPond coverage maps to give you a good idea if any
3G/4G reception is available in your area. The maps use some sort of computer
wizardry to determine if reception is most likely available so they aren’t pinpoint
accurate.
The second thing to do is wander around your property with a mobile phone or a
laptop with a 3G modem. By doing this you will be able to do speed checks,
determine reliability and narrow down area with better reception. Most smartphones
have an engineering menu you can access to give more detailed reception details.
Use Bing to search for instructions for your phone model.
Remember your site needs to have direct line of sight to your house!
Ubiquiti Networks have an online tool to plan wireless links called AirLink. It uses
Google Earth plugin (unfortunately) to put markers on the map where the stations
are. You can use the tool to see which radio will give a better quality signal.
If you have three bars or less, I strongly recommend you get yourself an external
antenna and try to boost reception. I tend to find that any less than 4 bars give
constant drop-outs and poor performance.
You may have more than one Telstra tower in your area that may offer a more
reliable connection. It is worth seeing if this is the case.
Finding Telstra towers I already knew where my nearest Telstra tower was but wanted to try and find any
other towers that may be closer to get better reception. This site shows tower
locations for Telstra and other 3G providers but it hasn’t been updated in years so I
rang BigPond support.
If anyone else wants to find Telstra towers then whatever you do, don’t call support.
The support staff don’t have access to this information and string you along instead
of being honest about not having a clue.
There are a few website you can use to find nearby mobile towers, some more
comprehensive than others. This site is the most comprehensive that I have found.
Page | 3
No reception on your property? Try somebody else’s! Unfortunately, I cannot get a strong enough mobile signal at my house. Even with an
external antenna on my roof, I can only connect for a few seconds before it drops out
for hours at a time.
My super-nice neighbour is lucky enough to have a tall hill on her property that can
get full five bar reception. Even luckier for me, she gave me permission to put a relay
station on her farm and wander up there whenever I like – free of charge.
The relay station (pushpin 2) is 1.75 kilometres from my house (pushpin 1) and
approx. 16km from the station as the crow flies (in the direction of the red arrow).
My location is in the open away from trees that may fall on it or cast shadows over it
(reducing solar output) and will be unobstructed by trees for a good couple of
decades.
Page | 4
Getting better reception
Having a strong signal should help lower any dropouts and improve the signal
quality.
With no external antenna, the site gets the full five bars of reception, an average ping
of 59 – 75 milliseconds and -70 to -80 dBm reception. With the modem lying on the
ground, it drops to 3-4 bars of reception.
With an 11 dBi antenna, I get -65 to -67 dBm. There isn’t a huge amount of
difference with or without an antenna, but the drop in signal strength with the
modem lying on ground level is the same as you’ll experience when the modem is
locked up tightly in a weatherproof enclosure.
Buyer beware
In the last year since I started planning my station, I’ve gone through three antennas
to try and get the best signal quality possible. The key thing learned about antennas
is antennas are not equal.
Don’t be tricked into thinking that the details and specifications listed for an antenna
are accurate. A perfect example of this is the 22 dBi antenna. Somebody on the
Whirlpool forums once said the only time it is 22dBi is on the marketing material. The
antenna is more like 14 dBi but in my experience gives worst results than this 10 dBi
antenna.
Beware of antennas that are made in China as the quality is very questionable and
the specifications are a work of fiction.
The antenna I have is the ZCG Scalar Y806A, giving 11 dBi gain and is made of
stainless steel (also comes in aluminium). The antenna:
Gives an accurate gain
Specifications are 100% correct
Is designed and made in Australia
The elements are welded to the boom and not screwed
No nylon/rubber caps
The aluminium version is not plated like the Chinese counterparts (evident by
the red rust on the them after being outdoors for an hour)
The ZCG antenna gives me -67 dBm compared to the -76 dBm from the Chinese
rubbish. The ZCG antennas are not cheap but a worth every cent in my opinion and
will most likely outlive me.
Page | 5
If the ZCG antennas are out of your budget, you can get a regular antenna in various
levels of gain from the internet. RF Shop, City Technology, Telco Antennas or eBay
are a few sites that sell Telstra 3G antennas (850MHz).
It is possible make your own for a bargain basement price. Here is a very long and
meaty forum post about making your own.
Page | 6
Solar power Components required
Constant uptime Since the relay station is remotely positioned with no access to mains power, it needs
to be reliable to enable it to run 24x7x365 from solar power.
The relay will draw the power it needs from a battery. This battery will also be used to
store a few days reserve power for inclement weather. A solar regulator is
responsible for charging the battery from the solar panel and distributing power to
the load.
Sunlight You need to consider how much sunlight your proposed site will get (insolation).
During winter, sunlight is not as intense and the days are shorter. It is a good practice
to base your power calculations off winter sunlight figures to ensure there is plenty
of power during the cooler months.
You can get the figures for your area in Australia here.
Power consumption To save money, I strongly recommend using a power meter to measure how much
your gear uses before buying the solar panel and battery. Solar panels and batteries
are quite expensive to chop and change if you get this wrong.
All the following calculations are based off the equipment in my station.
What size battery will I need? A deep-cycle battery is a type of battery that is designed to be regularly deeply
discharged using most of its capacity where car batteries are designed to provide
small amounts of power before being recharged. You need a deep-cycle battery for
the station.
1. Determine how many amp hours per day is used
a. 3 watts per hour = 72 watts per day / 12 volt system = 6 amps
2. Determine the battery storage required for 4 days of reserve
a. 6 amp hours per day multiplied by 4 days = 24 amps
b. 24/ 0.8 (AGM batteries can discharge to 80%) = 30 amp battery
Page | 7
I’ve gone for an AGM (Absorbent Glass Mat) battery. These batteries are a sealed
lead acid battery that can be safely discharged to 80% of their capacity without
causing any problems, don’t require any maintenance, can be used on their side and
have a long service life (8+ years depending on manufacturer and how you treat it).
Other types of deep-cycle batteries are Gel and flooded/wet cells.
How big does the solar panel need to be? Use the following calculation to work out what size solar panel is required. Batteries
don’t store 100% so the calculation needs to reflect this.
1. 6 amp hours / 0.8 battery efficiency factor / 4 hours of sun in winter = 1.875
2. 1.875 multiplied by 12 volt system = 22.5 watts
3. 4 days power (288 watts) / 5 hours of sunlight = 60 watt solar panel (rounded
up)
Step 3 factors in weather. If there is a rainy spell that lasts for 4 days and then the
next day it is sunny, that is 4 days of power to capture as it may start raining again. If
it rains a lot in your location, this step should be considered.
Draining the battery below 80% regularly may damage it, shortening the lifespan.
What size regulator do I need? You need to select a solar regulator that can handle more than the short circuit
current (Isc) of your solar panel (you can find this on the manufactures’ specs). An
extra 25% is added as a safe measure.
1. 3.9 amps (solar panel Isc value) multiplied by 1.25 = 4.875 amps
2. Round this up to the nearest size regulator
If you’ve chosen to use an AGM or Gel battery, make sure your chosen regulator
supports charging these battery types otherwise charging can result in battery
damage.
Summary To ensure plenty of power, the station’s power system requires:
30 amp hour battery for 4 days reserve power
60 watts of solar panel to aid in speedy recharge after rainy weather
5 amp solar regulator
Page | 8
Required parts Components required
Router that supports the 312U modem Not all 3G capable routers on the market support the 312U properly and some have
firmware issues. Routers made by MiktoTik support the modem with no troubles at
all.
I’m using 711UA-2HnD model which:
Uses very little power
Has inbuilt 2GHz 802.11b/g/n
Designed to run at temperatures up to 65°C so it won’t overheat in summer or
cook itself like the BigPond Elite Gateway (3G21WB)
Designed for remote installations and has no issues being run off solar
Don’t have to worry about the modem firmware or any software issues
MikroTik routers are powered by their operating system RouterOS.
Wireless link to your home The relay has a wireless radio on either end to send data back and forth. You need a
radio for the home end as the internet end of the relay is covered with the on-board
wireless.
Get yourself a cheap wireless radio by Ubiquiti Networks. These radios are powerful
and simple to use and once configured, it can be left alone with no need to ever
touch it again. Any Ubiquiti radio will do. I’m using the AirGrid M2 16dBi 2.4GHz.
They come in both 2.4GHz (can go through some tree patches) and 5.8GHz (useless if
you haven’t got a clear line of sight).
All Ubiquiti radios are powered via POE (power over Ethernet). This is a good reason
to use the on-board wireless with the MikroTik router as it saves having to worry
about POE and DC-DC power converters to run it from solar.
Get your Ubiquiti radio and shielded network cable from GoWiFi in New Zealand –
they always have them in stock and are a bargain compared to any store in Australia.
New Zealand and Australia share the same power sockets which is handy so you
don’t have to use another brand injector or power adaptors.
Page | 9
Mounting pole selection My station is in the middle of nowhere so I’m using a galvanised pole to mount the
equipment to.
I’ve since switched from a 48 mm (2 inch) pole with a light wall thickness to a 76 mm
(3 inch) with a medium wall thickness. The pole would shake back and forth in a
gentle breeze or with a light tap. This wasn’t causing any problems; I just preferred
something a little more solid. See render at bottom for comparison of poles.
My pole is 3.3 metres tall with 50 cm of that buried in the ground with three bags of
rapid set sand, cement & gravel mix.
Remember most antennas only come with mounts that support up to a 2 inch
pole – keep this in mind as you may not be able to get a larger mount for your
antenna.
You can source metal poles by using the Yellow Pages online and look under metal
merchants.
Enclosure selection You need an enclosure to house all the parts in and keep it safe from the weather. I
went for an enclosure that is roomy enough to house all the parts + the battery in
one spot with ample airflow.
L-Com sells excellent quality and affordable enclosures made of fibreglass with
reinforced polyester. Some models have cooling fans with a thermostat that turn on
at a set temperature and off again automatically which may be handy if it gets very
hot in summer where you live.
I also have this enclosure that I’m using it as a toolbox (mounted upside down so it
opens the same way as the main enclosure) to store screwdrivers, shifting spanners,
scissors, spare nuts and bolts, cable ties and a multimeter. It comes very handy in
case I forget to pack something I don’t have to walk another 4 kilometres to get it.
Solar panel mount selection To mount the solar panel to the pole you will need pole mount. Iron Ridge is one of
several manufacturers of pole mounts made in stainless steel, come with all the nuts
and bolts and easy to follow instructions.
An online sizing calculator is available to tell you what mount you need by entering a
solar panel model and the quantity of panels. Iron Ridge doesn’t sell panels directly
but Bing can help you or look at their distributors list.
Page | 10
Parts list All the parts I use in my station are listed below. To make it easy, the part itself links
to the manufacturer’s website and the country to the website where I purchased
from.
All prices are in the country of origin for each part and the cost of postage is not
included in any of the items.
Part Country Price
Ubiquiti AirGrid M2 2.4GHz 16dBi NZ $139
Ubiquiti ToughCable – 5 metre length NZ $8.25
MikroTik RouterBOARD 711UA-2HnD AU $89
ZCG Scalar Y806A stainless steel antenna AU $300
ZCG Stainless steel S48-76 mount AU $280
2m antenna cable N-Male to FME female x2 AU $44
Tight-fitting patch lead for 312U AU $15
ZCG 2.4GHz Yagi P2P antenna (Y2400-9) AU $350
MMCX to FME-Male plug pigtail AU $15
Steca PR 2020-IP solar regulator AU $200
SunTech 60 watt solar panel AU $682
IronRidge side-of-pole mount USA $77.90
ZCG 3" stainless steel U-Bolt (6167) AU $18
ZCG 3" stainless steel VEE block (6172) AU $55
Lifeline 12V 43aH AGM battery* AU $381.50
Battery leads with terminal lugs AU $20
Galvanised pole (3" OD, medium wall) AU $80
Glavanised top cap for pole AU $2.40
Quickset sand + cement + gravel (3 bags) AU $23.85
DC barrel jack adaptor AU $2.95
Weatherproof enclosure with cooling fan USA $189.99
Enclosure hole plugs USA $6.99
Universal pole mounting kit x2 USA $79.99
Blank aluminium mounting plate USA $21.84
Rubber bumper for mouting plate feet USA $13.95
Rubber bumper for battery feet USA $14.95
Custom length solar cables AU $40
Anderson power plugs AU $9.90
Total (accounting for exchange rates) ~$3,200
Page | 11
Shipping all the individual items from America to me would have cost a fortune. I
used Shipito to have all the items from the various suppliers sent to them to be
consolidated before being forwarded on to me.
The cost of shipping all the items via DHL Express (with insurance) was the same as
just shipping the enclosure to me by itself.
* Lifeline battery This battery is a perfect fit for the enclosure but it is a starting battery.
After several emails with a technician from Lifeline, the battery is more of a dual
purpose battery and will work with a solar application just fine without damaging it.
Lifeline does make a 33aH battery that you can purchase here. The battery I’m using
provides around and extra day and half power reserve.
Compared to version 1 As you can see, the cost is approx. $700 more with far better quality parts such as the
battery and antennas. There is a lot of money to be saved if you are not too fussed
on these items – around $700.
Solar regulator You might have noticed I’ve gone for a 20 amp regulator when only 5 is needed –
the Steca PR 2020-IP regulator is the only one that needs little ventilation room, has
a LCD screen (very handy), as load disconnect button and can be removed from its
enclosure.
Making sure everything will fit Since the enclosure was from USA and delivery times are quite long, it is good to
make sure everything fits so you aren’t trying to cram everything in or waiting weeks
extra as you’ve got to get another enclosure or another part.
Using a 3D modelling programme, I used the technical drawing available from
manufactures of the parts to make sure everything fitted nicely with plenty of airflow
and see if it would all work together.
If you don’t have the technical skills to make a 3D model, I highly recommend
making one from cardboard. It is far easier to know if there is enough room before
spending lots of money and time.
Page | 12
The top image is my beautiful, ILM quality render and the bottom is the result. Most
of the images were sourced from product brochures and manuals with the rest
coming from similar items. All items are correct to within a few millimetres of their
actual size.
Page | 13
How it will go together
Station The station end of the network is not as complex as you might think.
Home The home end is pretty straight-forward.
Page | 14
Setting up the Ubiquiti radio
Getting Windows to work with radio To set the Ubiquiti radio up to act as a wireless bridge between the station and your
house, you need to follow the steps below:
1. Plug the POE injector into a power point
2. Connect a shielded Ethernet cable to the radio and the other end to the jack
marked POE on the injector
3. Connect an Ethernet cable to the jack marked LAN on the POE injector and
the other end to a PC.
4. Right+Click on your network icon in the Notification area and click Open
Network and Sharing Center
5. Click on Change adapter settings
6. Right+Click on the network adapter the AirGrid is plugged into and click
Properties
7. Click on Internet Protocol Version 4 (TCP/IPv4) then click the Properties
8. Enter the details as below, and then click Ok. The radio is now ready to
configure.
Page | 15
Open a web browser and go to 192.168.0.20. By default, ubnt is both the username
and password.
1. Select Station WDS from the list
2. Enter a SSID – remember this as it will be the same on the MikroTik router
3. Choose a security method and a pre-shared key – remember this as it will be
the same on the MikroTik router
4. Press Change but do not click Apply just yet
Page | 16
Click on the Network tab and apply the following changes:
1. Select Bridge from the list
2. Make sure DHCP is checked
3. Press Change
4. Press the Apply button
Feel free to change any other items you want whilst you’re such as the country,
antenna type, time, device name, etc.
The radio will restart once you click apply and after it starts back up, it will be ready
to use. You can unplug it from your PC.
Remember to remove the IP you changed on the network adapter.
Page | 17
RouterBOARD setup
Connecting to the router After registering the modem, plug it into the USB port on the router, connect the
power and use an Ethernet cable to connect the router to your PC.
After powering on the router, use WinBox to connect to the router from your PC. It
does not need to be installed which is nice.
Upgrading RouterOS Depending on how long your router has been journeying around the supply chain, it
may have an out of date version of RouterOS. From my experience, the 312U modem
will not work at all on any version below 5.2. To see what version you have, look at
the title strip on WinBox.
If you already have a version 5.2 or higher, you can skip the next step if you’d prefer.
Newer versions include bug fixes so I’d recommended upgrading. To upgrade,
download the combined package for the RB700 series from the MikroTik download
page.
After downloading the combined package, click Files on the menu in WinBox. Drag
the downloaded file to the title strip in the files list – this will ensure it will be in the
root menu and not any other folders present.
Reboot the router and it will automatically upgrade RouterOS. Check the title strip to
confirm it went okay.
Page | 18
Configuring PPP-Client To create a connection to BigPond, go to Interfaces then choose PPP-Client from
the drop-down list:
Use the following instructions to finish creating the interface:
1. Give your PPP-Client a nice and meaningful name
2. Select the USB port from the list
3. Set both the info channel to 2 and the data to 3
4. The BigPond APN is telstra.bigpond
Page | 19
1. The phone number to dial is *99#
2. Your username is your full BigPond email associated with your BigPond
account
3. Your BigPond password
4. Make sure Dial On Demand (disabled will allow BigPond to automatically
connect without having to manually dial) is unchecked and Use Peer DNS
(tells the modem to use BigPond’s DNS servers) is checked
5. Click Apply
6. Click OK
The connection to BigPond is now complete. You can view network details, the IEMI
code of your modem (listed as serial number) and the mobile reception by clicking
Info… on the right-hand side.
Page | 20
Configuring NAT Go to IP->Firewall then click on the NAT tab and click on :
1. Set the Chain option to srcnat
2. Select the BigPond interface from the list
1. Choose masquerade from the list
2. Click Apply
3. Click OK
Page | 21
Updating the clock
Most RouterBOARDs don’t have a real-time clock. Every time the router is shutdown
or rebooted, the clock will revert to its favourite date in the ‘70s. This is fine if you
don’t care about the time, but having the correct time is useful when running scripts
or viewing events in the log.
To have the time automatically synchronized so you don’t have to manually set it
after every reboot, you can set up the SNTP Client. Go to System->SNTP Client and
set up the client as follows:
1. Check this box to enable the SNTP client
2. Change the mode to unicast
3. Enter a primary and secondary NTP server
4. Click Apply
5. Click OK
You can get NTP servers from the NTP Pool Project for your country. Copy and paste
the address e.g. oceania.pool.ntp.org. The IP will automatically be resolved and filled
in.
Page | 22
Creating a security profile A security profile allows you to protect the wireless link with a WPA2 key. Go to
Security Profiles tab then click :
1. Give the profile a meaningful name such as wpa2
2. Check WPA2 PSK. Uncheck any less secure methods
1. Enter the pre-shared key - this is the same as the one you chose the
Ubiquiti radio
3. Click OK
Page | 23
Configuring the bridge
Go to Bridge and then click on under the Bridges tab:
1. Give the bridge a meaningful name
2. Click OK
On the Ports tab on the Bridges dialog:
1. Select the Ethernet interface from the list
2. Select the bridge from the previous step
3. Click OK
Page | 24
Configuring the on-board wireless
Go to Wireless and then double-click wlan1 and under the Wireless tab:
2. Select bridge as the mode
3. Enter the network SSID – this is the same as the one you chose the Ubiquiti
radio
4. Select the security profile you’ve previously configured
5. Make sure the bridge is enabled
6. Click Apply
You can configure any other settings here such as the frequency, channel width and
band. If you clicked the Advanced mode button on the right-hand side, you can
choose your country and antenna gain.
Go to the WDS tab:
1. Select dynamic as the WDS mode
2. Select the bridge created previously
3. Click OK
Page | 25
Network details
The router needs an IP address, go to IP->Addresses then click on :
1. Enter the following IP: 192.168.88.1/24
2. Enter the IP 192.168.88.0
3. Select wds-bridge as the interface
4. Click OK
To enable the home end of the wireless link to plug into your home router’s WAN
port, you need to create a route. Go to IP->Routes then click on the red plus:
1. Enter 192.168.89.0/24 - remember this as it will be needed to configure
your home router
1. Enter the IP 192.168.88.2
2. Click OK
Page | 26
DNS
Go to IP->DNS then click on :
1. Give the DNS entry a meaningful name
2. Enter the IP 192.168.88.1
3. Click OK
Preventing remote unauthorised connections Every couple of days, dozens of retards try to remotely connect to my router. To
prevent any type of connection to your router except for WinBox, go to IP-Services
and click the red cross as shown below to any connection method you wish to block.
Page | 27
Home router configuration
To support your internet relay and allow it to connect to the WAN port of your home
router, you will need to make a couple of changes to your router. Since there are
hundreds of routers on the market, there are no pictures for this.
Any existing router you may have with a WAN port can be used. No special features
are required.
Internet connection
You need to configure your internet connection in the router as follows:
Connection type = static IP
Internet IP address = 192.168.88.2
Subnet mask = 255.255.255.0
Default gateway = 192.168.88.1
Primary DNS = 192.168.88.1
DHCP
My home router is the DHCP server for my network and I have the following details:
IP address = 192.168.89.1
Subnet mask = 255.255.255.0
Primary DNS = 192.168.88.1
These are the only settings you need to modify in your home router. If you would like
to use different IP addresses, then feel free to do so.
This was the last step in configuring the hardware
You now should be able to use the internet if you have followed all the steps exactly
as they are above.
Page | 28
Some assembling required
ZCG 2.4GHz antenna mount
No large pole mounts are available from ZCG to support poles larger than 48mm (2
inches). After discussing alternatives with ZCG, they did not recommend:
Drilling holes into the plate as it would make the holes too close to the edge
and it was designed as it was
Removing the radome as it is glued onto a bushing on the plate
As it turned out, the universal pole mounts that are used to mount L-Com enclosures
to poles has the holes in the right spot. Cutting them to the correct length (my metal
merchant did this for free) gives you a perfect custom made stainless steel mount
that is very inexpensive.
Using a circular saw with a regular wood blade sends lethal metal shards flying,
melts the mount leaving black burn marks on it and melts the teeth on your
blade. My metal merchant cut them for free.
Page | 29
Battery feet
I replaced the wooden box from my first version with sorbothane rubber bumpers.
They have 3M sticky adhesive already applied and it is just a matter of pulling off the
backing and sticking into place. The feet are tall enough to cover the cable gland +
the cables.
These feet allow some airflow around the battery + making it far easier to place the
battery in without having to worry so much about kinking the cables and getting
them caught under the battery.
Fan plugs
If I need to remove the mounting plate and take it home I would need to unscrew
the fan from the enclosure and take it with me. So don’t need to do this, I added
some small Anderson plugs.
Page | 30
Enclosure mounting plate
From my previous relay, I learned having a full-sized mounting plate was not needed
and caused too much hassle with cabling.
Since only the top portion of the plate is used, I measured what size it really needed
to be, covered of it with masking tape to protect the anodised coating then attacked
it with my circular saw.
I then placed the regulator and router on it and marked the holes before drilling
them. The rough edges can be sanded with ordinary fine grit sandpaper.
Page | 31
Once cleaned up, I removed the masking tape and attached some threaded/hollow
risers into the hole and screwed them on from the back. I already had these risers +
screw set from a previous project, but you can pick them up for cheap on eBay.
Keen observers may notice in the above picture, there are two holes in the middle
where the regulator goes. The thermostat from the original plate that came with the
enclosure I removed and attached here. It was placed under the regulator so it would
not be visible from the front.
Since the plate was cut, there is no longer any support down the bottom. Using the
same approach with the battery, I stuck sorbothane rubber bumpers on each of the
bottom corners to support the plate when pressure is applied.
Page | 32
Solar panel mounting kit
The solar panel mounts come with crappy worm-driven hose clamps. I don’t trust
them very much to hold the weight of the panel + the mount for a long time. I used
a 1 cm diameter U-Bolt (from ZCG) with some stainless steel washers and a Vee-
block behind.
This above method means the panel is rock-solid and does not wobble in the
slightest.
Page | 33
Assembling complete
Here is the new enclosure with all the wiring complete and fully operational.
Page | 34
AT commands
To issue AT commands to the modem, you will need to disable the BigPond interface
first as the channel it communicates on (channel 2) can either be used for internet
browsing or AT commands – not both.
To send AT commands to the modem, go to New Terminal and type the following:
Here is a list of useful commands to display bits and bobs of info:
Reset the modem: at!reset
Reception details: at+rscp?
Power details: at!pcvolt?
Modem temperature: at!pctemp?
The ID of the currently connected tower: at+upsc?
To exit the terminal, press the prefix key (Ctrl+A), then press Q. Remember to enable
the BigPond connection again to get internet access.
A full list of supported AT commands can be grabbed here in PDF form from Sierra
Wireless.
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Web-proxy
Storage
The RouterBOARDs don’t have an awful lot of space to use for a cache. Luckily, the
312U (and 320U) have an on-board Micro SD card slot. To make use of this, the
modem needs to have firmware version N2_0_8_5 or higher.
The latest firmware can be downloaded from Sierra Wireless.
Create the store for the cache
Go to System->Stores then:
1. Click Disks tab
2. Select the drive titled usb1
3. Click the Format Drive button
The status will change to ready once complete.
1. Go back to the Stores tab
2. Click the
3. On the dialog;
a. Choose a meaningful name
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b. Select Web-proxy from the dropdown
c. Select usb1 drive from the dropdown
d. Click OK
Enable the proxy
Go to IP->Web Proxy then click Web Proxy Settings on the right-hand side:
1. Check Enabled
2. Enter 8080 as the port
3. Choose a size for your cache – I’ve chosen 3 gigabytes and check Cache On
Disk
4. Click OK
The textbox with the label Cache Drive should show USB1 which is the Micro SD
card inside the modem.
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Make the proxy transparent
Making the proxy transparent will automatically redirect connected users to the
proxy without having to configure proxy setting on your home router or web
browsers.
Go to IP->Firewall then click NAT tab followed by the to create a new firewall
rule:
1. Under the General tab, select dstnat from the chain list
2. Select TCP from the protocols list
3. The port will be 80
4. Choose the bridge created previously, wds-bridge, as this is where the traffic
will be coming from
5. Under the Action tab, select redirect
6. Enter 8080 as the port (the port the proxy is listening on)
7. Click OK
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Block open proxy
If the proxy is not blocked, anyone can use your proxy service over the internet. To
block the proxy, go to IP->Firewall and click the under the Filter Rules tab:
1. On the General tab, select input from the list
2. The source address is 0.0.0.0/0
3. Select TCP from the protocols list
4. Enter 8080 as the port
5. Select your internet connection from the In. Interface list
6. On the Action tab, select drop as the action
7. Click OK
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Useful websites
Some interesting stuff on power calculations
A guide to run MikroTik routers from solar
Basic info on solar panels, regulators and batteries
Transparent web proxy – mine is based from this
MikroTik Wiki
MikroTik forums
A list of 3G modems and devices that are supported by MikroTik RouterBOARD*
Ubiquiti Networks Wiki – info on radio configuration is an updated version of this
Ubiquiti Networks forums
Ubiquiti Networks AirLink – free online tool to calculate wireless links
Shipito – mail forwarding from USA to Australia (cheap shipping)
VLRA battery – Wikipedia article all about AGM and Gel batteries
AT commands – full list of commands supported by most Sierra Wireless modems
AT command info – info regarding AT commands and Sierra Wireless modems
Solar transponder – a WhirlPool article on a solar repeater
Whirlpool forum homemade antenna – how to build your own for a bargain
RFNSA – site allowing you to search your local area for mobile towers
PV calculator – online performance calculator for PV systems
Relay v1 – my first doco covering version 1 of my station
Flickr gallery – totally awesome photos
The Whirlpool forums contain a plethora of information about mobile internet. This
Wiki post has oodles of information that is well worth a look.
* Most of the modems listed have been added by the forum community. If your
modem isn’t listed, it doesn’t mean it won’t work; most likely nobody has tested it
before.
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Nutritional info
Here are some statistics and fun (if you’re a geek) facts:
My station is 1.75km with perfect line of sight from my house
It is 4.4km return trip following the river
My nearest Telstra tower is 16km away with near line of sight
The Telstra tower is 333m above sea level
My station is 150 metres above sea level
My house is 60 metres above sea level
Over 30 trips went into assembling the station alone
I carted 25 litres of water with 8 litres only needed to mix the cement
It took seven months from start to finish
Skateboards do not work as a sled to tow a battery
An electric fence shock in the small of your back can make you nauseous
Approx. 55 kg in gear carried on foot to the station
Really nice photos
Check out my Flickr gallery for a whack of really nice, higher resolution photos.
Shortcut
If you are pressed for time or don’t feel like configuring the RouterBOARD then just
email me and I can email you a configuration file. Simple!
All you will need to do is change a few settings and the router will be up and running
in no time at all.
Feedback
If you’ve got any comments, questions or suggestions, feel free to email them to me.
I’ve spent a lot of time making my station and would appreciate any feedback.
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Gallery
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