Category Archives: Technology

Articles about general technology – illustrative but not necessarily about farm networking.

Getting the most out of your router – part 1

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wrt54g

The venerable Linksys WRT54G – Courtesy of Linksys

The world of networking is complex, including that little bundle of technology sitting on your shelf – your router. It is actually a pretty amazing little device that can probably do more than you realize. In truth, the typical “consumer” router is a combination of three devices:

  1. A router – a router is a device with two or more ports that is used to connect two or more networks together. Typically, the consumer router has a “WAN” port that connects to the “Wide Area Network” of your Internet Service provider and “LAN” ports for your Local Area Network.
  2. An Ethernet switch – you may have noticed that your router doesn’t have two ports; most actually have five: one WAN port and four LAN ports. Inside the box is an Ethernet switch that turns the LAN port of the router into 4 LAN ports to which you can connect wired computers, servers, and even additional Ethernet switches if needed. Actually, it’s 5 LAN ports, because the fifth one is connected to…
  3. A WiFi Access Point – this is simply a wireless radio connected to an internal LAN port that provides a WiFi signal for computers, tablets, smartphones, IP cameras, entertainment systems, and all kinds of other things. This WiFi radio is usually optimized for short-range, indoor use, providing maximum throughput for a short distance.

One of the odd and important facts about a router is that it has two Internet Protocol (IP) addresses: one on the network to which its WAN port is connected (which should be a public IP address, visible from the Internet – e.g. 108.162.198.52, ayrstone.com’s address), and one on the LAN port, the network it creates for you (a private address, not usable from the Internet, e.g. 192.168.1.1). Its job is to take data packets from each network and move them to their destination network. So, if your computer is at 192.168.1.50 on the LAN, and it receives a packet on its WAN port destined for 192.168.1.50, it passes it to the LAN port where it finds its way to your computer. Similarly, if your computer creates a connection to 108.162.198.52, the router receives packets from your computer on its LAN port and routes them to the WAN port. When you print to your networked printer (at, say, 192.168.1.100), it receives packets from your computer and then just turns them around and sends them back down the LAN port, since they are not destined for the Internet.

The ability of the router to accept traffic on a single public IP address and enable several different computers at private IP addresses to have separate “conversations” with the Internet is called “Network Address Translation” or NAT. The way it does this is by using “ports” – simply numbers associated with every IP address.

Each IP address has 65,535 possible ports. Some ports have pre-assigned purposes, some are available for use by applications, and some are ephemeral – here’s a good explanation of which are which. NAT uses those ephemeral ports to keep the conversations between your network and the Internet straight; for instance, your computer’s conversation with this website might be using your public IP address’s port 55135, while another computer on your network might be having a conversation with another website on port 61234. To the two websites, it looks like the traffic is coming from a single computer, specifically your router. Your router then routes the responses from the websites to the correct computer based on the port on which the data comes in.

The private IP addresses on your network are usually assigned by your router using Dynamic Host Configuration Protocol or DHCP. When a computer connects to your network, it will ask the router for an address via DHCP, and the router will provide it one (assuming it has one to provide). The address is referred to as a “lease,” because it will expire at some point after the device leaves the network, so it can be used by another device. However, note that you can simply assign a static IP address to a device in your network, as long as (1) it is an IP address inside your network (usually meaning it has the same three first numbers as everything else on your local network, e.g. 192.168.1.x) and (2) it does not interfere with the DHCP settings on your router (if your DHCP server begins at 192.168.1.50 and your router is at 192.168.1.1, use static addresses between 192.168.1.2 and 192.168.1.49, and KEEP TRACK OF THEM WHEN YOU ASSIGN THEM!!!)

The first tip for getting the most out of your router is this: set up your router’s DHCP server carefully. I suggest setting your router’s IP address as 192.168.1.1 and setting your router’s DHCP range from 192.168.1.50 to 192.168.1.254 (204 addresses). The reason for this particular range is that, first, it allows for a large number of devices to automatically use your router, getting private IP addresses via DHCP (204) but still leaves you 48 addresses you can use for devices you want to statically assign. This gives you the flexibility to maintain, expand, and control your home network.

Alternately, most modern routers support DHCP Reservations, which allow you to ensure that the router ALWAYS provides the same IP address to a device on the network. That way you get the advantage of a static IP address (knowing where a device is at all times) with the advantage of DHCP (ease of configuring devices and the IP addresses being managed by the router).

Click here to go to part 2

Myths about Wireless Farm Networking

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Myths are fun, but this guy won’t help you get the work done.

We have been talking about the myths of Wireless Farm Networking lately, and I wanted to add my own two cents worth here.

The article about the myths is excellent and stands on its own – I strongly suggest you read it. I thought I’d add a little about the topic here, by focusing on three aspects: Wireless, Farm, and Networking.

Wireless – I have seen “wired” farm networks – a number of livestock producers have trenched and buried fiber lines to their livestock buildings (Ethernet can only go 100 yards) for monitoring and control. However, it’s much cheaper now to go wireless, and it gives you much more flexibility. To build a good wireless network on your farm, you have to learn about “line of sight” (or, more correctly, Fresnel Zones) and position equipment so it has both power available and good radio signal from the rest of the network. It used to be that having a private wireless network across your farm was either technically impossible or cost-prohibitive, but we are proving that wrong every day.

Farm – A farm is pretty much defined as being in a rural area, and we’ve all seen that what works in town doesn’t necessarily work on the Farm, and vice-versa. The AyrMesh network is designed for farm use – relatively few people and machines spread out over a relatively large area. There are lots of good solutions for networking in town, where there are a lot of people in a small area, but they will never work as well as a solution designed specifically for the farm.

Network – The Internet Protocol (IP) network is the single, unified data communications medium for this century. I have seen farms that had a wireless link for their weather station, another wireless link for their GPS corrections, a home WiFI system and cellular coverage. Getting rid of the “point-to-point” solutions and putting everything on the network enables you to collect and transmit the data you need more easily, deliver what you need over the Internet, and gives you the option of adding new technologies to your operation quickly and easily.

Some people think this is revolutionary, but I would argue nothing could be further from the truth: this is the result of a clear evolution over time. In the 1970s academicians started tying computers together and transferring data over the first networks. In the 1980s networks came out of academia and started being used for business and even personal purposes; in the meantime, ham radio operators and researchers were starting to send digital data over radio waves. In the 1990s companies started to network their offices to share files and printers, as well as sending emails. Building-to-building microwave links became relatively common, and Industrial Automation moved to IP networks. In the 2000s the consumer internet became a reality, as did WiFi for wireless data, and we all got “on the net.” Now, in the 2010s, we have the Internet of Things and the low cost of high-power wireless networking, making this the decade of Wireless Farm Networking. The ability to monitor farm data and even control farm operations using a local network connected to the global internet will change agriculture forever.

Unmanned Aerial Vehicles (“Drones”) and Wireless Farm Networks

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One of the hottest topics in “Ag Tech” at the moment is Unmanned Aerial Vehicles (UAVs, also known as drones) and the role they can play for the farmer. Drones are hot right now, in Ag and other industries, because technology has made them much more adaptable and much lower in cost.

The possible benefits are tantalizing: an automatic, self-flying platform that can loft things into the air, take them where you need them, and take actions you prescribe. Just a few of the things drones can conceivably do for you:

  1. Take visible-light, near-infrared, and infrared photographs of all your fields at much higher resolution and in less time than satellite
  2. Get instant thermocline and other weather data (pop up 1000′ and check the temperature, wind speed, barometric pressure, etc.)
  3. “Run and get it” service for small items (see the beer drone and Amazon Prime Air)

When I was at the World Ag Expo a few weeks ago, there were several companies showing off drones and talking about drone-based ag services. Please make note of the distinction between drones and drone-based services, because, at the moment, it’s important. Or maybe not. I’ll explain as well as possible.

The Federal Aviation Administration has had a long-standing rule against the use of UAVs for “commercial purposes” – anything involving making money. Now, you can buy model airplanes with very sophisticated self-flying and video systems for fun or research, but not for any money-making purpose. However, a number of people couldn’t help themselves in making use of these amazing machines to enhance their businesses, and they have been getting “cease and desist” letters from the FAA. One guy named Raphael Pirker actually was fined by the FAA, giving him the opportunity to challenge the fine. He appealed to the National Transit Safety Board, and the administrative judge there ruled that the FAA did not have in place any actual regulations for the use of UAVs in non-navigable airspace, and therefore could not enforce the fine against Pirker. There’s a good article about this in Scientific American.

So, apparently, one currently can use UAVs for commercial pursuits, with some (not entirely clear) limitations. I’ll bet if you take your drone anywhere near a commercial airfield, for instance, you’ll get to meet some members of law enforcement and spend time with them. I’ll bet if you take your drone near any government installation, you will get to spend a serious amount of time with members of law enforcement and/or the military. In either case I’ll wager you’ll get to contribute a good amount of money to the government. And there are undoubtedly some private citizens who will happily shotgun your UAV out of the sky on sight.

I’ll also wager that the FAA (or some other part of the government) will create some rules about UAVs to protect people from stuff falling out of the sky on top of people and property, and having our neighbors peeking in 2nd (or 102nd)-story windows. But, for the moment, it looks like the skies are open, particularly out in the rural areas, and I expect farmers to be the first to benefit from UAVs. Some people like Chad Colby are already talking publicly about the opportunities.

Honestly, I think the current “state of the art” is mostly a plaything: the drones that are currently available are mostly manually radio-controlled and focused on live picture-taking. UAVs I have seen that might be put to use on the farm must be charged, taken to the field, flown around the field, and then the pictures (or other data) downloaded off the UAV (by bluetooth, WiFi, or transfer from some kind of flash card). This is a significant commitment of time, which limits how often you can really use the drone. A crop scout may be able to save a lot of the time he would normally spend by using a UAV to survey fields, but there’s benefit to the grower having a drone or drones that would continually survey fields.

The reason I am particularly interested in Ag Drones is because I believe they can become an important part of the day-to-day information-gathering apparatus. To be truly useful, however, I believe they must be:

  • Autonomous: flying over your fields automatically without intervention. Ideally, they would have a “home” out in the field where they would stay, and they would do their flying at specific times with no human interaction needed.
  • Smart: able to recognize problems and take appropriate action – recognize if there is something different in the fields, avoid danger, and report back
  • Connected: automatically uploading data collected and sending alerts to you as needed. For instance, a drone flying over your fields taking infrared photos might use the wireless farm network to automatically upload the pictures to a service that automatically scans them for anomalies indicating crop stress.
  • Self-maintaining: self-charging and self-monitoring, needing little maintenance and letting you know when it needs “help”

My own vision is that an Ag drone should be programmed with pre-configured flight paths and connected via WiFi with a wireless farm network for constant (or at least mostly constant) communication. It should be able to download changes to its schedule and pre-configured flight paths off the network, and It should also be able to land on a platform that will automatically charge the drone’s batteries for the next flight. Set up this way:

  • The grower, scout, or agronomist doesn’t have to go out and mess around with the drone – it can just do its thing as often as it needs to (pending charging of the batteries)
  • The data can be automatically collected on the grower’s PC or on a central server (on the farm or on the Internet) – it can even be automatically processed and problems (plant stress, aberrant weather conditions, etc.) can be automatically reported to the grower
  • The drone works for the farmer, not the other way around.

All the pieces exist today to create drones that can meet these criteria, but I’m not aware of any pre-built planes or copters that are ready-to-use. However, there are open-source software projects that have built auto-pilot systems for drones and other robots (e.g. the ArduCopter), and there is discussion of induction charging of quadcopters in the “DIY” forums. And heavier-lift copters (capable of picking up fairly heavy items and transporting them) are also in the works. Imagine being able to get out your cellphone and “tell” your copter to bring you the parts you forgot back at the workshop, then hearing it whirring its way toward you a few minutes later. And then, when it delivers them, it DOESN’T TELL YOU YOU’RE AN IDIOT for forgetting the parts. For me, that would be nearly priceless.

In short, I think there are a lot of possible benefits from using UAVs on the farm, and I’m eager to see them start to deliver those benefits. However, I think a lot of the benefits are greatly enhanced by having the UAVs connected to a wireless farm network – I believe the two technologies will work hand-in-hand, each enhancing the value of the other.