Overview Of Wireless Low-Power MCUs on the 2022 Market

Low Power ESP32 Module

With the Internet of Things (IoT) quickly gaining mainstream attention, the market for, especially wireless, microcontrollers was never broader. We’ll explore MCU solutions for different types of applications including Bluetooth Low Energy, ZigBee, Bluetooth/Wi-Fi meshes, and more!

Use cases

Which communication method should you use? Wi-Fi, Bluetooth, ZigBee, Thread, and others are all different quite different wireless communication protocols. Depending on your projects needs, one will definitely be more suitable than other so let’s go and compare them.

Parameter Wi-Fi ZigBee Bluetooth Low Energy LoRa Thread
Data transfer speed Up to 300 Mbps 20 - 250 kbps 125 kbps - 2 Mbps 27 kbps - 50 Kbps 250 kbps
Operating frequency 2.4 GHz 868 / 915 MHz, 2.4 GHz 2.4 GHz 169 / 433 MHz (Asia), 868 MHz (Europe), 915 MHz (North America) 169 / 433 MHz (Asia), 868 MHz (Europe), 915 MHz (North America)
Operating range ~ 200 m (~ 660 ft) 10 - 100 m (30 - 300 ft) 10 m (30 ft) 5 km (3 mi) - urban areas 15 km (10 mi) - rural areas/clean line of sight 100 m (300 ft)
Coincell battery life (power consumption) N/A Depending on usage, more than a year Depending on usage, more than a year Depending on usage, more than a year Depending on usage, more than a year
Maximum amount of inter-connected nodes 2,007 65,000+ 8 Up to 1000 additional End Nodes 250+ (maximum of 32 routers)
Nice to mention Most widely used form of consumer wireless communication Most widely used form of consumer wireless communication Most widely used form of consumer wireless communication Most widely used form of consumer wireless communication

Top players on the market

Espressif

One of the most popular semi-conductor companies related to IoT in the past few years with a rich portfolio of wireless microcontrollers, development environments and a big community that makes it even better.

ESP32

No doubt that ESP32 is one of the most loved. and most popular Espressif’s MCUs with both Bluetooth and Wi-Fi. It’s designed to operate in really harsh environments, capable of handling -40℃ to 125℃

ESP32 offers ultra-low power consumption. In deep sleep, ESP32 draws almost 150µA. Assuming you use a 2200mAh battery, that would last you an outstandingyearars and 8 months of use!

Antenna switches, RF balun, power amplifier, lnoisesie receive amplifiers, filters and power management modules are all built-in in the ESP32

Pros

  • Astonishingly low-power consumption
  • Relatively low-cost
  • Big community and lots of open-source libraries

Cons

  • Starting a Wi-Fi connection can be a bit power demanding
  • Not straight-forward to integrate with existing Arduino projects

ESP8266 / ESP8266EX

Both ESP modules offer a 32-bit. RISC-based, Tensilica processor running at a clock speed of 160MHz. They’re very similar to ESP32, offering the same built-in features.

They’re also capable of functioning in high-demand industrial environments

Real-Time Operating System (RTOS) support is really good, with many open-source RTOS available for rapid use and integration.

ESP32-S2

ESP32-S2 is a security-oriented MCU from Espressif featuring secure boot and flash encryption

The private key and device secrets are separated and protected from software access.

ESP32-S2 has specific cryptographic accelerators for enhanced performance and protection against physical fault injection attacks.

S2 can drive displays, touch sensors and it offers 42 GPIO pins!

Pros

  • Offers RSA-3072 secure boot and AES-128//192/256-XTS flash encryption
  • Has a dedicated cryptographic accelerator unit
  • Security-oritented

Cons

  • I2C at 100kHz bus runs very slowly
  • Deep sleep and wake up sources
  • No DAC-based audio output

ESP32-S3

ESP32-S3, its twin ESP32-S2 is a security-oriented MCU, designed for AIoT supporting both Wi-Fi and BLE5, powered by a dual-core XTensa LX7 at 240 MHz with 45 GPIOs.

AI accelerator adds support for vector instructions

Besides secure boot and flash encryption, S3 has a digital signature and HMAC.

Unlike S2, it offers high-speed octal SPI flash and PSRAM

Pros

  • Secure boot, flash encryption
  • Digital signature and HMAC
  • Vector instructions
  • High speed SPI flash and PSRAM

Cons

  • No current Arduino support

ESP32-C3

A RISC-V based MCU with Wi-Fi and BLE5, supporting both BLE and Bluetooth long-range, running on a single core at 160 MHz with 22 GPIOs.

C3 can work in BLE SIG and Espressif Wi-Fi Furthermore meshes.

Like S2 and S3, it offers secure boot and flash encryption.

Pros

  • Single-core, cost-effective alternative to ESP8266
  • Integrade USB/serial and JTAG make it easy to exchange files and data via USB
  • Supports Arduino framework

Cons

  • Relatively new, may not be as widely supported as previous ones

ST

STM32WB series

STM32WB series of MCUs support BLE5.2, IEEE 802.15.4, ZigBee and thread, running either individually or concurrently.

With ST’s enormous ecosystem, it’s easy-to-use and implement other development boards from their family.

Series offers end-device trustability and anti-cloning features. It uses certified and free-of-charge radio stacks.

Comes in very popular packages - UQFN48 to UFBGA129 or as a ready-to-use module.

  • STM32WBx0 - dual-core WMCU based on Arm Cortex-M4 @ 64MHz
  • STM32WBx5 - Arm Cortex-M4 @ 64MHz and an Arm Cortex-MO+ core @ 32MHz
  • STM32WBxM - wireless module addresses 2.4GHz solutions with BLE, 802.15.4 protocols, including ZigBee, Thread, as well as proprietary protocols

STM32WL series

STM32WL are all LoRa-enabled SoCs, which makes them suitable for very long-distance communication. They’re fully open and support multi-modulation.

It is an ideal choice for LPWAN (Low-power Wide Area Networks) and IoT devices.

Without compromising on performance, SoCs from STM32WL series offer ultra-low power consumption.

  • STM32WL5x - Arm Cortex-M4 and Arm Cortex-M0+ @ 48MHz, and a sub-GHz radio-based Semtech SX126x, STM32WL5x supporting LoRa, (G)FSK, (G)MSK and BPSK modulations
  • STM32WLEx - Arm Cortex-M4 @ 48MHz, and a sub-GHz radio-based on Semtech SX126x, STM32WL5x supporting LoRa, (G)FSK, (G)MSK and BPSK modulations

Texas Instruments (TI)

TI offers a wide range of MCUs for different applications. For an easier overview take a look at TI’s website .

NXP

NXP has a very, very wide range of MCUs for quite a lot of applications. We’ll cover some of them:

  • 2.4GHz Audio streaming
    • NXH3670UK - Arm Cortex-M0+, 2.36GHz to 2.5GHz carrier frequency
      • BLE4.2 - 1Mbps and 2Mbps PHY modes
      • 8.5mW at the headphones side
      • Sleep current < 63uA
      • Continous RX current < 3.7mA @ 1.2V
      • Continous TX current < 7.3mA @ 1.2V
      • Interfaces: SPI, UARTs, GPIOs, I2S
      • Latency < 20ms
      • WLCSP 34 package
  • BLE
    • KW39/38/37 - Arm Cortex-M0+, 2.4GHz, BLE5, < 10mA for receive
  • DSRC Safety modem
    • SAF5100 - AEC-Q100 qualified, SAF5100 is a software-defined radio processor providing a V2X system solution for intelligent transport systems applications
    • SAF5400 - The RoadLINK SAF5400 is an automotive-qualified single chip DSRC modem for V2X applications.
    • SXF1800 - The SXF1800 is a Secure Element IC, which provides tamper-resistant cryptographic functionality for V2X applications as defined by ETSI 102 097 (EU) and IEEE 1609.2 (US) standards.
    • TEF5100 - The TEF5100 transceiver architecture is based on direct conversion for both the transmitter and receiver, which eliminates expensive external filters.

Ambiq Micro

Apollo

  • Ultra-low power, highly integrated microcontroller designed for battery-powered devices including wearable electronics, activity & fitness monitors
  • Arm Cortex-M4 with Floating Point Unit
  • Enables complex sensor processing tasks to be completed with unprecedented battery life
  • 512KB flash and 64KB RAM
  • Memory Protection Unit
  • Wake-up interrupt controller with 12 interrupts

Apollo2 MCU / Apollo2 Blue

  • Integrated BLE controller
  • BLE5-ready radio
  • 1 MB of flash memory and 256 KB of RAM
  • SPI and I2C
  • Arm Cortex-M4

Apollo3 Blue / Blue Thin

  • Ambiq’s SPOT-based Apollo MCU family
  • DMA engine
  • QSPI interface
  • Advanced stepper motor control
  • PDM inputs

Apollo3 Blue Plus

  • Everything as Apollo3 Blue / Blue thin, including following:
  • 2 MB of flash memory and 768 KB of SRAM
  • Analog watch hand management
  • Ambiq’s Voice-on-SPOTTM
  • 2 additional MSPI modules, that increase external memory execute-in-place (XiP) aperture from 64 to 96 MB
  • 74 GPIOs

Apollo4 BLE5.1 / M4F

  • The Apollo4 SoC family is the 4th generation system processor solution built upon Ambiq’s proprietary Subthreshold Power-Optimized Technology (SPOT) platform.
  • Powered by 32-bit Arm Cortex-M4 with Floating Point Unit (FPU)
  • Up to 2 MB of MRAM and 1.8 MB of SRAM
  • Suitable for battery-powered endpoint devices, including smartwatches, childrens’s watches, fitness bands, animal trackers, far-field voice remotes, predictive health and maintenace, and the smart home

Mediatek

MT3620

MT3620 is a Microsoft Azure Sphere MCU with extensive I/O peripheral subsystem. MT3620 features an Arm Cortex-A7 application processor operates up to 500MHz and includes large L1 cache and L2 cache and integrated SRAM for highly efficient operation over a wide range of potential applications. Two general purpose Arm Cortex-M4F I/O subsystems running at up to 200MHz support the requirements of the many on-chip peripherals including 5x UART/I2C/SPI, 2x I2S, 8x ADC, up to 12 PWM counters and up to 72x GPIO, allowing a diverse range of potential applications.

MT2533

MT2533 is a dual-mode Bluetooth SoC with integrated DSP for smart wireless headphones. It combines Arm Cortex-M4, 4 MB of memory (PSRAM and flash), Bluetooth 2.1/BLE4.2 and Audio Analog Frontend.

Designed for audio management, MT2533 integrates a Tensilica HiFi Mini Digital Signal Processor (DSP). This DSP supports multiple codecs, dual microphone and speech enhancement features, including native dual microphone noise reduction (DMNR) and support for third-party software for voice wake-up

Filogic family

Filogic family incorporates Wi-Fi 6 and Bluetooth 5 combo chip for consumer devices. It enables multi-gigabit networking in a wide range of consumer devices, with segment-leading power efficiency and performance.

The Filogic 320 includes a multi-protocol baseband, integrated MCU, and a simultaneous dual-band architecture (2.4GHz, 5GHz). When paired with a MediaTek Filogic Network Processing Unit or other application processor the platform can deliver multi-gigabit Wi-Fi speeds via its 2x2 antenna. Wi-Fi/Bluetooth co-existence enables both networking technologies to operate simultaneously, while Bluetooth 5.0 integration offers seamless wireless interaction with smartphones, tablets, personal devices and other smart home products.

Nordic

Nordic is a semi-conducor company specialized in wireless MCUs and offers wide variety of devices for different applications. From low-power cellular IoT to ANT and proprietary protocols, Noridc offers many devices, but we’ll cover a few of them that are the best in their respective categories.

Low-power cellular IoT

  • nRF9160 - Low-power SIP with integrated LTE-M/NB-IoT modem and GNSS

BLE

  • nRF52 Series
  • nRF5340 SoCs (supports direction finding and Bluetooth mesh)
  • nRF52840 - ZigBee support

Range extenders

  • nRF21540 RF FEM

Conclusion

Since we’ve covered a lot of devices in this article, it’s not possible to pick a single one and call it the best. Depending on your application, you can reference this article to get a grasp on different functions, abilities and features of specific devices that will help with the development of your project.