32-bit MCUs Penetrate IoT Ecosystem
Microcontroller manufacturers are gearing up to serve the Internet of Things sector with 32-bit devices that enable designers to lower power and cost.
While 8-bit and 16-bit MCUs are well suited for IoT end-node applications, the 32-bit MCU has a key function in the IoT pyramid: It provides the data throughput, reading sensors and sending real-time sensor data over an IP-based network. The 32-bit architecture allows designers to put low-power connectivity next to it and communicate directly to the Wi-Fi access point or GSM modem.
Silicon Labs' latest addition to its 32-bit MCU portfolio includes the EFM32 Zero Gecko family based on the ARM Cortex-M0+ core. The MCUs are designed to achieve the lowest system energy consumption for battery-powered IoT applications such as smart meters, security systems, and wireless sensor nodes, as well as systems powered by harvested energy.
"32-bit MCUs—and in particular those based on ARM processors—are clearly the sweet spot for the connected device market," said Daniel Cooley, senior director of marketing, microcontroller products, Silicon Labs Inc., Austin, TX. "ARM Cortex-M processors are becoming the de facto standard choice for most connected device applications that require a combination of ultra-low power and low cost."
The EFM32 Zero Gecko MCUs feature an energy management system with five energy modes that enable applications to remain in an energy-optimal state, spending as little time as possible in the energy-hungry active mode.
Microchip's 32-bit MCU line covers devices ranging from inexpensive, low pin-count parts for sensor measurement up to devices focused on advanced connectivity. Its more advanced parts include the PIC32MX6 and MX7 devices, which offer increased flash and RAM memory sizes, faster core operating frequencies up to 100 MHz, an 10/100 Base-T Ethernet connectivity. Microchip also recently released PIC32MZ series of devices, offering up to 2Mbytes of flash and a core operating frequency of 200 MHz.
"As advances are made into low-power operation of 32-bit devices, a higher percentage of the IoT market will become 32-bit MCU based." said Brett Novak, principal marketing engineer, MCU32 division, Microchip Technology Inc., Scottsdale, AZ.
"In the bigger picture of the IoT, there are devices ranging from simple Bluetooth LE 'beacons,' which broadcast basic environmental details, to high-end data concentrators with advanced connectivity. In our beacon application, we want a simple, very small, very lower-power MCU capable of running on coin cell batteries for extended periods of time, connected to a simple Bluetooth LE radio. While this is traditionally served with
8- and 16-bit devices, advances in process and clocking are allowing 32-bit devices to become more competitive in this space."
Atmel offers several products aimed at the IoT sector. They include the SmartConnect SAM R21 single chip, which combines an ARM Cortex-M0+ based 32-bit microcontroller and 2.4-GHz RF transceiver. It offers a link budget of 105 dBm while consuming 50% less current than the existing offerings, according to Eieland. It also recently introduced SmartConnect WiFi, a new family that integrates Atmel's ultra-low-power MCUs and wireless connectivity solutions into an easy, turnkey IoT solution that can directly connect to a Wi-Fi access point.
"In addition to low power and cost, the 32-bit MCUs tailored for the IoT must be easy to use," said Andreas Eieland, Atmel Corp.'s senior product marketing manager.
"For all IoT devices, ease of use will be essential, with the projected growth there is no room for devices that are cumbersome to configure, hard to program, or products where vendors do not provide all the network and peripheral coded needed," Eieland said, adding that the company provides all source code for free through the Atmel Software Framework.