We often hear about the Internet of Things (IoT). The vision is to connect sensors, machines, appliances, vehicles, even signs and roadways, to the Internet. A huge portion of IoT growth is expected to be wireless. In this blog, I'll take a look at some wireless machine-to-machine (M2M) solutions and the capabilities they provide.
Last month, Martin Rowe reported from Cisco’s Bill Swift’s DesignCon keynote that "by 2020 50 billion devices will be connected to the Internet." A lot of these will be some kind of M2M connection. ABI Research recently reported that M2M cellular module shipments increased 21 percent in 2012 and will reach 100 million in 2015. As you will see below, this will mean billions of physical connections.
In another Cisco forecast, global M2M traffic grows at 86 percent CAGR through 2016 to over 500 petabytes per month (500 million gigabytes!). That forecast also is based mainly on cellular M2M data, so the actual M2M data traffic is more, once you include local network connections.
An M2M gateway can do a lot of things, but at least it will have a network connection plus one other I/O connected to something. You need gateways to send the collected data or measurements to a network where you can do something with the information. Even a simple smart-sensor comprising a temperature sensor connected to a cellular modem is its own gateway, but gateways can do a lot more. The network link can be Ethernet via a wire, or a cellular/WAN wireless connection, routing through a service provider onto the Internet. Another option is via WiFi to a local network.
The I/O side of the gateway provides options to connect things to the network. To support all the connections, most devices include a microprocessor, usually based on an ARM core. For example, Laird Technologies offers the SDC-WB40NBT (Figure 1) module designed to be integrated into customer electronics and provide connectivity between WiFi and other I/O. Other than antenna connectors, the physical interface is through a Kyocera 120-pin connector located on the lower edge of the board. This product is targeted at OEMs designing M2M products.
Figure 1. Laird Technologies SDC-WB40NBT module.
You can see an Atmel chip, which includes a 396MHz ARM9 core supporting all the I/O. To the left is a Broadcom chip providing 802.11a/b/g/n and Bluetooth 3.1EDR (up to seven simultaneous connections). Laird says it provides Linux as the user development environment. The company also says it will soon offer a version with twice the memory and supporting Bluetooth Low Energy (BLE). The range of I/O possibilities is shown in the block diagram. Ethernet, UART, USB, 2-wire (including CAN Bus), serial, SDIO (SD Card interface), GPIO, and analog (voltage) I/O are provided. Drivers are pre-loaded for all I/O.
The user manual shows that the input power (the 3.3VDC shown in the diagram) uses three power pins and three ground pins, and all the other signals have their own ground pins. That should help reduce problems with power, as well as crosstalk issues. Given all the I/O options, this device may find its way into industrial monitoring, security, telematics, and other applications.
Continue to Part 2