The “Internet of Things” (IOT) has been a hot topic for years. Connecting “things” is something everyone seems to be doing. Back in 2014, I was at forefront of getting "Thing" on the internet with the NXP Kinetis K64 MCU!
https://hackaday.com/2014/04/16/building-the-internet-of-thing-at-ftf2014/
"Thing" came with a command line interface over a TCP connection:
Figure 2. The Thing Command Line Interface
If you want a good chuckle, there are some additional details on the hackaday site:
https://hackaday.io/project/778-internet-of-thing
The Case for Cellular Industrial IOT
All the "things" that make modern life possible are driven by large machines which represent a large capital investment that carry continuous maintenance costs. These large machines are part of a value stream that allow a business function. Like any device made by humans, these machines require upkeep and maintenance. In many cases an organization pays a technician to routinely check and repair the machine. The technician’s time and overhead costs money. It does not matter if the technician is internal to the organization or is part of a vendor’s maintenance team for which you pay a service fee. The best case is that the technician can routinely (say monthly) inspect these machines and show up for repairs when there are issues. After all, when the machines making Oreo cookies goes down, we need a solution ASAP!
In this scenario, you can put a dollar figure to the cost of routine maintenance checks and repairs. This monthly “subscription” is the cost of doing business. Instead of paying someone to perform maintenance checks on a routine basis, why not automate the data collection and use the power of the cloud computing to make inferences of about what is going on? One you understand the bottom line of your operating and maintenance costs, you can now see where the IOT - and the cellular IOT- is an incredible value. I have observed many people turned off by the idea of “monthly” fees for IOT. In the context of the scenario I have presented, it is the most inexpensive way to do business and it provides continuous value. You can know the state of your critical processes anytime, anywhere. In fact, local to me there is a company who saves companies hundreds of millions a year using the Industrial IOT model.
For this concept to work, we need our sensors and edge devices to get to the Internet. I argue that *cellular* communication is an inexpensive, secure and reliable way to provide connectivity for these scenarios. There are new cellular protocols, namely CAT-M1 and NB-IOT, which enable low power (even battery powered) connectivity solutions and are backed by networks which have had billions of dollars of investment. Some may say “Why not WIFI, isn’t that free?”.
Nope! Network connectivity is never free. You can always trace its cost to somewhere or someone. Think about a network engineer’s time and consider a fully burdened rate of $150USD/hour. This is not an unheard of true cost to pay for a network security engineer to audit and provision devices With cellular, you can end up with data plans that are a few dollars per month. If the report rate is small, it can be sub dollar a month. Ask yourself this question:
If the problem you are solving does not warrant a few dollars a month in being able to access information remotely, is there even value in monitoring the asset or process?
If we are talking about machines that cost 10’s or 100’s of thousands of dollars, the decision is very simple. The idea of “parallel” networking has been very important component in securing the Industrial IOT. Using cellular, one can send a solution that is ready at unboxing which does not need to touch a customer’s internal network.
The global cellular network for sensors has had 10's of billions of dollars of investment allowing access to the one of the most advanced wireless network humans have built.
An Interesting NXP Powered Cellular IOT Application
With cellular, a customer can get connectivity out of the box without incurring the expense of a network engineer on every deployment We can even isolate the network traffic, so the IOT solution is never visible to the public internet. Data is available and secure. When you need reliability, easy installation, and instant customer value, cellular is a great option. I am currently working on fermentation monitoring platform for craft brewers. For the TZero Brew service, we are often asked if it is Wi-Fi enabled. The short answer is, “No”. For many products, Wi-Fi is an awful choice, and ends up eating away at the value proposition of the product. This may seem contrary to popular opinion, but when you focus on customer value, it is easy understand why. The goal is to deliver continuous value, and get in the brewery without interrupting a brewer’s daily workflow. If the solution is not easy to install and deploy, it is not providing value.
Figure 3: A Cellular Connected Ultrasonic Fermentation Monitor
The TZero Brew product starts with an NXP powered Ultrasonic Probe. The raw is data processed in the MCU "at the edge" with a reduce data set transmitted to the "cloud" through a cellular network. We then use the power of cloud processing to do more complicated algorithms to estimate the state of the fluid over time so brewers can knowledge of what is going inside fermentation vessels anytime, anywhere.
Figure 4. Anytime, Anywhere access to your Process.
This particular application extends beyond brewing. We can remotely access critical fluids, such as glycol in $150k chillers, to keep critical processes running and machines operating smoothly without requiring some to routinely take samples of the fluids. We are even available to power the next generation of bio-farms for Synthetic Biology applications!
Sure, for delivering Instagram and YouTube, Wi-Fi is a useful data pipe. For an industrial grade service offering, Wi-Fi does not always provide the most value to the customer. At TZero, there have been two general scenarios that we have encountered when getting sensor data into the Cloud:
- You walk into a customer location and there is a consumer-grade router and switch in a back room. Great. You’re given the Wi-Fi password and the default SSID. How is that for security? Are you willing to let your service quality be controlled by a consumer-grade router in a closet? Even the best intentions yield spotty service and poor security.
- A larger organization will almost certainly have IT staff and some form of digital security policy. In this scenario, you will not be able to connect to their network (wired or wireless) without some level of audit. It will not be simple. This can potentially take weeks of red tape and approval. How much does a network engineer cost for hours of their time? Both the customer and solution provider incur a non-trivial deployment cost.
Our solution bypasses the connectivity conundrum completely by using cellular. Couple that with the fact that some equipment may be outside and have no WIFI connectivity. The solution is ready and configured on day one. It is true that cellular coverage is not everywhere, but I would argue that is in most places where critical processes are. It can cover a huge swath of applications. Couple that with the fact that technologies such as CAT-M1 and NB-IOT can reach further than the modulation schemes used in your phone's cellular chipset. This capability is baked into the 3GPP standards and they were engineered for the IOT.
There is often confusion that "Edge Processing" and "Cloud" solutions are distinct offerings. In my opinion, they should be combined to enable truly remarkable offerings.
This is where the LPC55S69 can come into the picture.
Combining the LPC55S69 w/ Cellular Communications
In previous articles, I showed that the LPC55S69 has a ton of great features for sensor data processing with the PowerQuad, security features with the Cortex M33 and CASPER while offering two cores for implementing your logic at the edge. Pair it with a cellular modem and you have a great starting point for Industrial IOT applications.
In this series of articles, I am going to show the LPC55S69 being connected to a cellular network using a Digi XBEE3 CAT-M1 cellular module. The Digi module is a great starting point as you get a well-documented, easy to use pre-certified module that can accelerate your development.
Figure 4. Digi CAT M1 Pre Certified CAT M1/NB-IOT Cellular Modem
To get started, I designed a simple “shield” for the LPC55S69-EVK to be able to connect to the Digi modem. Thanks to JLCPCB and their low cost 2-layer service, $2 + shipping got me a quick breakout board to attach the modem to the LPC55S69-EVK.
Figure 3: Its Turtles All the way Down! The XBEE3 Cellular Adapter
At this point in life I rarely wire things up by hand. PCBs are so inexpensive for prototypes that I almost always start with designing a PCB Putting it all together, I have a nice development platform for the Digi XBee3 cellular module with the LPC55S69:
Figure 4. The LPC55S69-EVK with Cellular Shield
I hope I have given you some points to consider about cellular IOT. Next time, I am going to show you some basic operations you can do with the LPC55S69 and a cellular modem. Because security is always on everyone’s mind, I will be showing off the wolfSSL stack and how to get it running on the LPC55S69. In my opinion, wolfSSL is the best embedded C library for handling SSL/TLS connections. It is the most rigorously test security stack currently on the mark. It can be ported to just about any platform, has extensive documentation and also includes extra software such as wolfMQTT and wolfSSH which will enable you next secure industrial IOT application. I have been using the wolfSSL “stack” to connect to cloud based IOT services such as Azure IOT Hub.
In the meantime while I am putting together the demonstrations checkout, Digi and WolfSSL:
https://www.digi.com/products/embedded-systems/digi-xbee/cellular-modems/xbee3-cellular-lte-m-nb-iot