This month’s Datasheet rounds up nine microcontrollers (MCUs) that come equipped with built-in RF capabilities. Whether via Wi-Fi, Bluetooth, or another RF capability, the selection of devices in the following gallery covers an array of wireless needs—everything from smart home to industrial to medical applications.
As microcontrollers (MCUs) evolved to contain more and more powerful CPUs, the tendency among designers was to devote more of the IC package to these CPUs and leave the memory and peripheral functions to be handled by external chips. And on the customer side, if you required a more powerful CPU, you likely also needed better and more precise peripheral function blocks (and memory) that were best handled using external devices, anyway. Hence, the trend in MCUs for some time was toward more powerful CPUs and less “stuff.”
Today, of course, designers can fit a powerful CPU and a host of peripheral devices into one or two large IC packages. We know and love these powerful new chips as Systems-on-Chips (SoCs), containing most of the peripheral devices needed to make, for example, a personal computer. SoCs are found in Raspberry Pis, single-board computers (SBCs), streaming TV boxes, routers, and so forth.
Notably, while these devices do just about everything else, they typically did not, for a while, have built-in Wi-Fi or Bluetooth. So, when Espressif Systems introduced the ESP8266 in 2014, containing built-in Wi-Fi in addition to everything else found in existing MCUs, it sold like hotcakes. Its successor—the ESP32—added Bluetooth and has proven to be still more popular.
Nevertheless, MCUs with built-in Wi-Fi remain something of a niche class of devices. The smaller applications for which MCUs are used are low-power, often battery-operated, and Bluetooth is of course a much better fit for such applications than Wi-Fi. But any application that either needs to be autonomous (that is, not tied to any Bluetooth host) or needs to transfer large amounts of data (such as a video signal) will probably have to budget the power to run Wi-Fi.
This month’s Datasheet focuses on MCUs with built-in Wi-Fi, Bluetooth, or other RF capabilities. The following gallery features some big names, like the aforementioned Espressif, or like Nordic Semiconductor, who have an exciting first offering in a new SoC series. It also includes some, perhaps, lesser-known players—namely, EDATEC, an official design partner to Raspberry Pi based in China. Where possible I highlighted devices with built-in Wi-Fi, but Bluetooth and Bluetooth Low Energy remain the wireless technologies of choice for many of the latest MCUs and SoCs.
Industrial Embedded Computer Built Around a Pi
EDATEC, one of two China-based companies who are official design partners to Raspberry Pi, released an industrial embedded computer built around the Raspberry Pi Compute Module 4. The CM4 Industrial features a powerful quad-core CPU with up to 8GB RAM and up to 32GB eMMC, and comes with two RJ45 ports, a 4G/LTE module, certified 2.4/5.8G dual-band Wi-Fi, Bluetooth, and support for external antennas. The device targets the industrial control, intelligent manufacturing, Internet-of-Things (IoT) gateway, and advertising display markets.
- Quad-core CPU w/ up to 8GB RAM and up to 8GB eMMC that can be used simultaneously
- Dual LAN support with 1x Gig-Ethernet and 1x Fast Ethernet (100Mbps)
- Support for a wide range of wireless options that include dual-band Wi-Fi, Bluetooth, and 4G LTE with optional GPS
- Industrial interface w/ an 8V-36V DC power input, battery backed real time clock (RTC), SPI-based Flash, 1x Rs232, 2x RS485, 3x ADC channels, 2x isolated display interface (DI), and 1x SPDT relay
- Metal case acts as a heat sink to reduce CPU speed down-shifting
- Support for DIN-rail and wall mounting
MCU Built for Matter
No gallery of RF-enabled MCUs would be complete without an offering from Espressif. In recent years, the company has proven to be the manufacturer of choice for many prototypers and embedded developers—the ESP32 is often featured in Circuit Cellar’s pages. Espressif’s recently released ESP32-C6, currently in mass production, offers Wi-Fi 6 (2.4GHz), Bluetooth Low Energy (BLE) 5.0, and 802.15.4 (Thread and Zigbee) in a 5x5mm package. Built around a single-core 32-bit RISC-V processor at up to 160MHz, the ESP32-C6 is aimed at smart connected devices, especially those using Matter and/or low-power Wi-Fi.
- Single-core 32-bit RISC-V processor up to 160MHz
- 512kB SRAM
- Wi-Fi 6 802.11b/g/n/ax 2.4GHz with target wake time (TWT) for low-power Wi-Fi applications
- Zigbee 3.0
- Thread 1.3
- Embedded USB CDC and JTAG (no need for an external debugger)
- Parallel IOs up to 16-bit
- Event Task Matrix (ETM)
- Trusted execution environment (TEE) controller and access permission management (APM)
- 2x TWAI controller, compatible with ISO 11898-1 (CAN Specification 2.0)
Peripheral-Rich MCU Ready for Seamless Multi-Protocol Implementation
Microchip’s PIC32CX-BZ2 MCU System-on-a-Chip (SoC) is a wireless microcontroller rich with peripherals. The device is BLE 5.2 and Zigbee 3.0 certified, the software stacks for which were built on the MPLAB Harmony v3 framework to enable seamless multi-protocol implementation so designers can focus on their end product. This MCU is aimed at solutions in smart home and industrial automation applications, such as home appliances, HVAC sensors and controls, smart doors and locks, motor control, and intelligent lighting. This SoC is part of a larger PIC32CX-BZ2 family that also includes modules.
- 64MHz Arm Cortex M4F processor
- 1MB Flash with Error Correction Code (ECC)
- 32KB nonvolatile read Flash
- 128KB multi-port programmable Quality of Service (QoS) SRAM
- 29 GPIOs
- Internal and external clock options
Powerful, Efficient, Secure Multiprotocol SoC
Nordic Semiconductor’s nRF54H20 is a fourth-generation multiprotocol System-on-a-Chip (SoC). The device is the company’s first SoC in the recently-announced Bluetooth Low Energy (BLE) nRF54H series—following Nordic’s award-winning and popular nRF51, nRF52, and NRF53 series—that features a new hardware architecture fabricated on the GlobalFoundries 22FDX leading process node. Built on multiple Arm Cortex-M33 processors and multiple RISC-V coprocessors (all of which are clocked up to 320MHz and optimized for a specific type of workload), the nRF54H20 is ideal for IoT applications that demand high processing power, excellent energy efficiency, and state-of-the-art security.
- Multiple Arm Cortex-M33 processors, clocked up to 320MHz
- Multiple RISC-V coprocessors
- 2 MB non-volatile memory
- 1 MB RAM
- Bluetooth Low Energy, LE Audio, Bluetooth mesh, Thread, and Matter
- New peripherals: High-speed USB (480 Mbps), CAN FD controller, 2 x I3C and 14-bit ADC
- Designed for PSA Certified Level 3 IoT security standard
- Physical security
Secure Tri-Radio Device For Interoperable Smart Solutions
NXP Semiconductors’ IW612 is a secure tri-radio device that brings highly integrated 2.4/5GHz dual-band 1×1 Wi-Fi 6, Bluetooth and BLE 5.2, 802.15.4, and Matter. The device enables simultaneous transmit and receive for higher performance in smart solutions, and comes with a full-feature Wi-Fi subsystem powered by NXP’s 802.11ax (Wi-Fi 6) tech to bring high throughput, network efficiency, low latency and an improved range. The IW612 is geared toward multiple IoT and industrial smart applications.
- Dedicated, independent CPUs and memories for Wi-Fi and Bluetooth
- Efficient power management system supports deep-sleep low-power mode
- Single and dual antenna configurations
- Wi-Fi: 1×1 2.4/5 GHz, up to 80 MHz channel, UL/DL MU-MIMO and OFDMA, TWT
- Bluetooth: Bluetooth 5.2, integrated high power PA up to +20dBm transmit power
- 802.15.4: IEEE 802.15.4-2015 compliant supporting Thread in 2.4GHz band, integrated high power PA up to +20 dBm transmit power
A Power Supply Ready For Harsh Industrial Environments
Renesas’ RA4W1 is a low-energy, single-chip 32-bit MCU with 48MHz Bluetooth 5.0. The device comes with 2Mbit high-throughput (HT) and long-range support, and is intended for IoT applications needing a high-performance core (such as the Arm Cortex-M4 core its built on). With an efficient low power process as well as open and flexible ecosystem support provided by its FreeRTOS-based Flexible Software Package (FSP), the RA4W1 has full function support for BLE 5.0 long-range and mesh networking.
- 48MHz Arm Cortex-M4
- 512kB Flash Memory and 96kB SRAM
- 8kB Data Flash to store data as in EEPROM
- 7×7 mm QFN 56-pin package
- Capacitive touch sensing unit
- Segment LCD controller
- USB 2.0 Full Speed module supporting host and device mode
Dual-Band MCU Design for Long-Range Networks
Silicon Labs just debuted the FG28 SoC, a dual-band MCU designed for long-range networks and protocols like Amazon Sidewalk, Wi-SUN, and other proprietary protocols. It includes radios for sub-GHz (supporting device communication over one mile) and 2.4GHz BLE, and it comes equipped with a built-in AI/ML accelerator for machine learning inference. The FG28 also comes with Silicon Labs’ Secure Vault, its suite of security features geared to address IoT threats. This device is ready for edge applications in smart agriculture, smart cities, and neighborhood networks.
- The industry’s first integrated AI/ML hardware accelerator in a sub-Ghz SoC
- 1024 kB of flash storage and 256 kB of RAM
- Industry-leading Secure Vault Mid and High support
- Energy-efficient radio core with low active and sleep currents with fast wakeup times
- Up to 49 General Purpose Input/Output (GPIO) pins
Embedded Flash Memory in This 32-Bit MCU
STMicroelectronics’ STM32U595, part of the STM32U5 series, is an advanced, power-saving MCU based on the Arm Cortex-M33 (running at 160MHz with TrustZone for Armv8-M) that is designed to meet requirements for smart applications. With up to 4MB of flash memory (touted at the first 32-bit MCU with embedded flash memory) and 2,514KB of SRAM, the STM32U595 is built on an ultra-low power platform and provides a high level of integration.
- High energy efficiency: Innovative power management features; LPBAM, DMA, and IP autonomous in LP mode
- High integration: Up to 4MB internal flash memory; Up to 2.5MB RAM; USB HS with integrated PHY
- Higher security and safety: AES and PKA, side attack resistant; ECC on flash memory and SRAM
- Advanced graphics capabilities: First STM32 with advanced graphics accelerators and NeoChrom GPU
- Improved data storage: 100kcycles for 512Kb of flash
MCU Optimized for Low-Power Wireless Communication
Texas Instruments CC2340R5 SimpleLink Bluetooth 5.3 Low Energy wireless MCU is a 2.4GHz microcontroller targeting BLE and proprietary 2.4GHz applications. It’s optimized for low-power wireless communication with on-chip dual image Over-the-Air Download (OAD) support in building automation, asset tracking, and medical, retail, and personal electronics applications. It comes with Zigbee protocol stack support in the SimpleLink CC23xx Software Development Kit (SDK), and has an ultra-low standby current less than 0.71μA.
- Optimized 48MHz Arm Cortex-M0+ processor
- 2.4GHz RF transceiver compatible with Bluetooth 5.3 Low Energy
- -102dBm for Bluetooth Low Energy 125kbps
- -96.5dBm for Bluetooth Low Energy 1Mbps
- 512KB of in-system programmable flash
- 12KB of ROM for bootloader and drivers
PUBLISHED IN CIRCUIT CELLAR MAGAZINE • July 2023 #396 – Get a PDF of the issue
Sam Wallace - became Circuit Cellar's Editor-In-Chief in August 2022.
His experience in writing, editing, and teaching will provide a great perspective on the selection, presentation, and clarity of editorial content. The Circuit Cellar audience will benefit from his strong academic background encompassing a Master of Fine Arts in Writing and a Bachelor of Science in Mathematics with honors. His passion for learning and teaching is a great fit for Circuit Cellar's continuing mission of Inspiring the Evolution of Embedded Design.