Deliver Power, Performance, and Versatility in Meager Square Millimeters
Design spaces have become increasingly smaller as system developers try to cram more embedded functionality into IoT projects. Now, tiny, embedded boards are more capable than ever of packing CPU, GPU, memory, and I/O resources onto minuscule slivers of printed circuit board real estate.
A funny thing happened when Raspberry Pi launched the successor to its famous RP2040-based Pico board in August of this year. One of the company’s bloggers reported that the Raspberry Pi Pico 2 with the RP2350 MCU has twice the performance of its predecessor and includes many of the features it originally intended to deliver with the RP2040. On the previous launch, it either couldn’t find the real estate to include essential features such as security, or the silicon didn’t exist with the right power/performance/cost metrics to offer the full spectrum of critical features.
The RP2040 is legendary despite any perceived shortcomings. Still, Moore’s Law has seemingly caught the wave of the tiny, embedded boards, and the RP2350 has plenty of processing horsepower, memory, and I/O resources packed into a 21mm-x-51mm board. Although many projects featuring the RP2040 have been documented on Circuit Cellar’s pages, including this edition, one can only imagine what projects the RP Pico 2 might inspire with a more complete allotment of computing resources.
But the revolution the Raspberry Pi inspired with Pico doesn’t cover everything that tiny, embedded boards have to offer. Developers might have a familiar PCB and want to add functionality to another board. To add WiFi and Bluetooth connectivity, for example, just order Espessif’s ESP32-PICO-MINI-02U module, and viola, the project has all the wireless connectivity a project might need while only sacrificing 13.2mm x 11.2mm x 2.4mm (0.52” by 0.44” x 0.09”) of PCB real estate. It is the tiniest board mentioned in this month’s selection of tiny, embedded boards.
Discreet functionality is just one of the magical benefits of an explosion of tiny boards. For example, a host board might be unable to accommodate a thermopile sensor, so Mikroe in Sweden offers IR Thermo 4 Click in a 28.6mm x 25.4mm (1.12” x 1”) form factor. It’s easily added through the company’s clickboard connectors. Still, you would have to ensure the host system is compatible to capture the functionality it provides for skin temperature monitoring, over-temperature protection, human presence sensing, and motion detection.
Or maybe you’re obsessed with inertial measurement units. In that case, Adafruit enables a standalone IMU breakout board featuring the classic MPU-6050 triple-axis accelerometer plus gyro combo to feed your host all the data it needs for a sensor fusion application. It doesn’t take much to add, with dimensions of 26.0mm x 17.8mm x 4.6mm or 1” x 0.7” x 0.2” and 1.8g (0.1oz) weight.
If computational ambitions exceed the typical MCU performance parameters but space is still a major constraint, then consider Nvidia’s Jetson Orin Nano, which packs 472 GFLOPS of AI performance into 69.6mm x 45mm of PCB real estate. Run multiple streams of high-resolution steaming video simultaneously or operate multiple neural networks in parallel. This baby can handle it.
Staying with more industrial IoT applications, where’s my robot? I need my hourly foot massage. Oh, I see; it’s recharging again. I thought it took its regular “coffee break” 30 minutes ago. Well, no problem; I will replace it with a bot running an EmbeddedTS TS-4100, which typically uses only 1W for an Arm Cortex-A7-based NXP i.MX 6UltraLite and operates up to 696MHz with WiFi and Bluetooth on a 75mm x 55mm board. My feet can’t wait to get pampered all day.
Tiny, embedded boards such as these and profiled on the following pages give you the performance, power efficiency, versatility, and added functionality needed for various applications without making your system design balloon like an overhydrated camel.
Add an IMU to Me
If sensor fusion is what you’re after, the MPU-6050 triple-axis accelerometer plus gyro combo has been the go-to inertial measurement unit for eons, seemingly. Adafruit puts this in a breakout board MPU-6050 6-DoF Accel and Gyro Sensor that needs no solder. Just hook up your favorite microcontroller with I2C and the accelerometer indicates the direction toward Earth and the gyroscope senses how fast the board is being twisted around. It is included here because it was used in a recent Circuit Cellar issue, #412, “Catching Lightning in an IMU.”
- 26.0mm x 17.8mm x 4.6mm
- 1.8g/0.1oz weight
- 3.3V Feather/Raspberry Pi
- 5V Arduino/Metro328
- SCL pin
- 12C clock connector
- 0.1” standard header
- 4 2.5mm (0.1”) mounting holes
- Adafruit library download
- Python/Circuit Python
- Arduino drivers
- 3VDC-to-5VDC step down regulator
- 3Vo
- SDA -I2C data pin
- STEMMA QT connectors
- Interrupt pin
- AD0 I2C Address pin
- Advanced FS, SCE, SDE, and CLKIN
- Gyro X-, Y-, and Z-axes sensors
- External sync connected to FSYNC pin
- 3 integrated 16-bit ADCs
- Bias, sensitivity temperature stability
- Digital output triple-axis accelerometer
- ±2g, ±4g, ±8g and ±16g range
Arduino Nano
The Arduino Nano is small, complete, and breadboard friendly. It’s based on the ATmega328 (Arduino Nano 3.x). Measuring only 18mm x 45mm PCB size, it has the same functionality as the Arduino Duemilanove, but in a different package. It lacks only a DC power jack and works with a Mini-B USB cable instead of a standard one. The rest is up to you.
- ATmega328 8-bit AVR architecture microcontroller
- 2.7V to 5V operation
- 32KB Flash memory
- 2KB SRAM
- 16MHz clock speed
- 16 MIPS throughput
- Fully static operation
- On-chip two-cycle multiplier
- 10,000 flash/100,000 EEPROM cycles
- 1.5mA at 3V, 4MHz active mode:
- 1μA at 3V power-down mode
- 8-channel 10-bit ADC
- Programmable serial USART
- 8 analog IN pins
- I2C: A4 (SDA) and A5 (SCL)
- 1KB EEPROM
- 20mA DC current per I/O Pins
- 7V to 12V input voltage
- Sleep modes – Idle
- Power-save
- Power-down
- Standby
- Extended standby
- 22 Digital I/O Pins
- SPI: 10, 11, 12 , 13
- 19mA power consumption
- 18mm x 45mm PCB size
- Auto range: –40°C to 125°C
That One Watt
How much work can you perform on 1W of power? Typically, the EmbeddedTS TS-4100 ultra-low power, standalone IOT-ready system on module operates an Arm Cortex-A7-based NXP i.MX 6UltraLite operating up to 696MHz with Wi-Fi and Bluetooth. And this is all before lunch in a 75mm x 55mm form factor. And what have you done?
- 1W typical power usage
- Wi-Fi
- Customizable off-load engine
- Rugged, industrial environment ready
- -40 °C to +85 °C temperature range
- NXP i.MX 6UL
- (Arm Cortex-A7 @ 696MHz)
- 4GB MLC eMMC,
- Up to 1GB RAM
- MicroSD slot
- 802.11b/g/n; Bluetooth LE
- USB OTG Micro-AB USB receptacle
- USB console output with Micro-B USB receptacle
- 2 10/100 Ethernet ports
- I2S Audio
- USB Host
- USB OTG
- I2C Bus
- 46 DIO
- 2 CAN
- 4 PWM
- SPI Bus
- ZPU: FPGA includes integrated ZPU
- 32-bit CPU for RT offloading
- CPU-ZPU memory access to ZPU
- 5VDC input power
- Dimensions: 75mm x 55mm
Express Yourself Wirelessly
When space is the primary consideration for design, there might be some tradeoffs on performance. Not so, says Espressif. Just add the ESP32-PICO-MINI-02U module with dimensions of just 13.2mm x 11.2mm x 2.4mm (0.52” x 0.44” x 0.09”), the tiniest embedded board in this review. Get all the WiFi, Bluetooth, and Bluetooth LE you need in IoT applications for home automation, smart building, consumer electronics, and industrial controls.
- ESP32-PICO-V3-02 SiP
- 240MHz Xtensa dual core 32-bit LX6 microprocessor
- 2.4GHz WiFi + Bluetooth + Bluetooth LE module
- 8MB Flash
- 2MB PSRAM
- 27 GPIOs
- 448KB ROM for booting
- 520KB SRAM for data and instructions
- SD card
- UART
- SPI
- SDIO
- I2C
- I2S
- IR
- GPIO
- ADC
- DAC
- TWAI
- Ethernet MAC
- 802.11n up to 150 Mbps bit rate
- Bluetooth V4.2 BR/EDR
- 3.0V ~ 3.6V operating voltage
- –40°C ~ 85°C operating temperature
Sensitivity from Afar
Mikroe offers the IR Thermo 4 Click as a compact add-on board for precise sensing applications. Suited for remote skin temperature monitoring, over-temperature protection, human presence sensing, and motion detection, the board features the Excelitas TPiS 1T 1386 L5.5 H thermopile sensor known for high accuracy and narrow 5-degree field of view. Used for host systems built on the MikroBUS standard, developers can take advantage of this board’s 28.6mm x 25.4mm (1.12” x 1”) dimensions.
- Excelitas CaliPile TPiS 1T 1386 L5.5 H thermopile sensor
- 5° FoV
- EEPROM data storage
- Isothermal TO-39 package
- Integrated 50µW signal processing
- Ambient and object temperature sensing
- Integrated lens hood
- Minimizes stray light
- Enhanced thermal stability
- Mid-field human presence sensing
- Far-field human motion detection
- Passive light-barrier for people counting
- Built-in ADC and multiple filter options
- Operation Voltage: 2.6V to 3.6V
- Sensitivity S40: 60 Counts/K
- Time Constant: 15ms
- Accuracy < 0.3 K
- I2C interface
- 3.3V input voltage
- Interrupt function for presence, motion, over-temperature
AI Edge Innovation
Here-a-flop,there-a-flop, everywhere a Giga FLOP, which is, in the parlance or our times, Giga Floating Point Operations Per second, or FLOPS 109 (or ten to the ninth power). Nvidia’s Jetson Orin Nano series evaluation boards modules deliver up to 40 TOPS of AI performance in the smallest form-factor. The evaluation board is 100mm x 79mmx 21mm and the standalone boards are 69.6mm x 45mm.
- 40 TOPS
- 1024-core NVIDIA Ampere architecture GPU with 32 Tensor Cores
- 625MHz GPU performance
- 6-core Arm Cortex-A78AE v8.2 64-bit CPU
- 1.5MB L2 + 4MB L3 memory
- 1.5 GHz CPU performance
- 8GB 128-bit LPDDR5 memory
- Storage: SD Card Slot & external NVMe via M.2 Key M)
- 1080p30 video encode s
- 4K60 (H.265) video decode
- 2 4K30 (H.265) video decode
- 5 1080p60 (H.265) video decode
- 11 1080p30 (H.265) video decode
- 2 MIPI CSI-2 22-pin connectors
- 4 PCIe Gen3 M.2 Key M
- 2 PCIe Gen3 M.2 Key M slot
- M.2 Key E slot
- 4x USB 3.2 Gen2
- USB Type-A connector
- USB Type-C connector for UFP
- GbE connector
- 40-Pin expansion header (UART, SPI, I2S, I2C, GPIO)
- 100mm x 79mmx 21mm
Picture Perfect Orange Pi
Picked primarily because it offers a 64-bit processor, the Orange Pi 3B is powered by Rockchip RK3566 quad-core made in 22nm advanced process technology, with up to 1.8GHz main frequency. An integrated ARM Mali G52 2EE graphics processor with OpenGL ES 1.1/2.0/3.2, OpenCL 2.0, Vulkan 1.1 support makes it ideal for 4K output high-definition quality. Have fun stuffing this 56mm x 89mm board into a flat panel.
- RockchipRK3566 CPU
- Quad-core 64-bit Cortex-A55 processor
- ARM Mali G52 2EE GPU
- OpenGL ES 1.1/2.0/3.2, OpenCL 2.0, Vulkan 1.1
- Embedded 2D acceleration hardware
- Integrated RKNN NPU AI accelerator
- 4K@60fps H.265/H.264/VP9 video decoding VPU
- 1080P@100fps H.265 video encoding
- 1080P@60fps H.264 video encoding
- RockChip RK809-5 PMU
- 2GB/4GB/8GB LPDDR4/4x
- 16GB/32GB/64GB/128GB/256GB memory
- SPI Flash: 16MB/32MB
- M.2 M-KEY slot
- SATA3 or PCIe2.0
- NVME SSDs
- Micro SD slot
- Wi-Fi+BT
- 10/100/1000Mbps Ethernet
- HDMI TX 2.0 , 4K@60fps video output
- 1*MIPI DSI 2 lane
- USB 3.0 HOST
- 2 USB 2.0 HOST
- Dimensions: 56mm x 89mm
More Power, Same Tiny Size
Raspberry Pi Pico 2 upgrades the previous generation Pico RP2040 chip with a high-performance RP2350 microcontroller, boasting dual ArmCortex-M33 cores or dual Hazard3 RISC-V at 150 MHz. It’s paired with a PIO interfacing subsystem and a comprehensive security architecture based on the Arm Trust for Cortex-M.
On board Flash memory has been doubled to 4MB compared to its predecessor. With board dimensions, 21mm × 51mm, the Raspberry Pi Pico 2 has an operating temperature range from -20°C to +85°C.
- Dual Arm Cortex-M33 or
- Dual Hazard3 RISC-V processors @ 150MHz
- 520 KB on-chip SRAM
- Pico 1 SW, HW compatible
- Drag-and-drop programming
- Castellated module allows soldering direct to carrier boards
- Enhanced security features
- ARM TrustZone for Cortex-M
- Optional boot signing
- Enforced on-chip mask ROM
- Key fingerprint in OTP
- Protected OTP storage
- Global bus filtering
- Arm or RISC-V security/privilege levels
- Hardware mitigations for fault injection attacks
- Hardware SHA-256 accelerator
- 2 UART
- 3ADC channels
- 12 PIO state machines
- Operating temperature -20°C to +85°C
- 1.8VDC to 5.5VDC input voltage
High Performance at Low Power
Balancing high performance and low power is always a delicate dance and Seco offers the SMARC module powered by the Qualcomm QCS6490 processor with he options of one Arm Cortex-A78 @2.7GHz, three Arm Cortex-A78s @2.4 GHz, and four Arm Cortex-A55 @1.8 GHz on an 82mm x 50mm board for applications in industrial automation, digital sig
- QCS6490 processor
- LPDDR5-6400 up to 12GB
- LVDS dual-channel 18-bit/24-bit
- eDP V1.4,
- MIPI DSI 4 lanes
- Display Port through USB 3.1 Type C
- Primary display: FHD+ @120 fps
- Secondary display: 4k Ultra HD @60Hz
- Qualcomm AdrenoTM 643L GPU
- 64GB eMMC 5.1 drive on-board
- SD 4-bit interface
- UFS 2.x/3.1 flash option
- 2 gigabit Ethernet interfaces
- Optional Wi-Fi + BT5.0
- USB 3.1
- USB 2.0 OTG
- 1 USB 2.0 or 4 USB 2.0 (Hub option)
- 2 UART (RX/TX/RTS/CTS)
- 2 UART (RX/TX)
- CAN via SPI
- I2C
- Ultra-low power RTC 2xPWM
- 50°C to 60°C commercial range
- -30°C to 85°C industrial range
- Size: 82mm x 50mm
- Edgehog OS
- Data orchestration
Datasheet URLs:
Adafruit: https://www.adafruit.com/product/3886
Arduino: https://store-usa.arduino.cc/products/arduino-nano
Embeddedts: https://www.embeddedts.com/products/TS-4100
Espressif: https://espressif.com/sites/default/files/documentation/esp32-pico-mini-02_datasheet_en.pdf
Mikroe: https://www.mikroe.com/ir-thermo-4-click
Nvidia: https://www.nvidia.com/en-us/autonomous-machines/embedded-systems/jetson-orin/#tech-specs
Orange Pi: http://www.orangepi.org/html/hardWare/computerAndMicrocontrollers/details/Orange-Pi-3B.html
Raspberry Pi: https://datasheets.raspberrypi.com/rp2350/rp2350-datasheet.pdf
Seco: https://www.seco.com/Datasheet/Modules/SMARC/SOM-SMARC-QCS6490_datasheet.pdf
PUBLISHED IN CIRCUIT CELLAR MAGAZINE • DECEMBER 2024 #413 – Get a PDF of the issue
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Tom Murphy has been plying his trade as a technology journalist for more than 25 years, first as an editor/writer/reporter and then as a communications professional. He has earned industry recognition for both journalistic endeavors and technology campaigns. Before joining Circuit Cellar magazine as editor-in-chief (2024), Tom wrote tech briefs, newsletters, blogs, press releases, white papers, and technical articles for numerous clients, primarily in the semiconductor industry. His introduction into the industry came as an editor for “Electronic News” covering microprocessor companies, the fabless semiconductor phenomena, communication chips, and many others. When he’s not tapping away at the keyboard, Tom learns Dungeons and Dragons terminology from his 10-year-old daughter and walks his bulldog (slowly) around the block.
