The Internet of Things (Part 3)

摘要

In our first installment, we talked about the various ways we have connected our embedded systems wirelessly to the Internet. In Part 2, I covered the various decisions that need to be made in choosing a carrier for your embedded system. This month we will look in detail at how we have connected simple devices wirelessly to the Internet. Yesterday, we had a new potential client fly in to see us to discuss their need to create an Internet of Things (IoT) device for their very non-electronic company. This company has been in business for over 50 years making and innovating extremely low-tech products. Now they wanted their extremely low-tech product to be wirelessly connected to the Internet. They came to us with a prototype developed by their general manager using an Arduino and a development kit. This was a man who had no electrical engineering background. It was quite impressive. He did not have any complications sending the data to the cloud. He did struggle with designing the sensor to obtain the data he desired. With the feasibility behind them and after becoming knowledgeable enough to know what it takes to join the IoT revolution, they wanted us to turn it into a product. This shows how easy it is to take a simple microcontroller, talk to a complex cell module, and create a device that will soon join the IoT revolution. Many of our systems are similar to theirs and use a very simple microcontroller with very little memory. Some cell modules offer a good assortment of options for connecting to the web. Since some of the module manufacturers we use require an NDA to obtain their documentation, we will only talk about our experience with a Swiss company called u-blox who freely publishes their technical documentation on-line. In particular we will talk about the features of the LISA C200, which supports CDMA. Other modules have similar functionality. Figure 1 shows the basic system architecture that we will be reviewing this month.