Dev Kit Weekly: STMicro's STM32U5 NUCLEO-144 Evaluation Board
July 29, 2022
Video
You can see how fast you could get into deep water with what probably started out as a desire to take some simple measurements. Fortunately, ST has a life raft for Industrial IoT prototypers in the form of STM32U5 NUCLEO-144 evaluation boards like this one for the STM32U575ZIT6Q MCU.
Image source: https://www.st.com/resource/en/user_manual/dm00789949-.pdf
The STM32U5 portfolio is a family of extreme low-power secure microcontrollers designed around a 160 MHz Arm Cortex-M33 CPU with a single-precision floating point unit, DSP instructions, a memory protection unit, and a bunch of specialized math, imaging, and crypto accelerators. All of that is enough to efficiently capture and analyze sensor readings at the edge even if you’re running on a battery or other limited power supply because STM32U5 devices draw just 110 nA in shutdown, 300 nA in standby, and as little as 19 µA per MHz in active mode.
If you’re the trust but verify type, check out EEMBC’s ULPMark and SecureMark benchmarking databases to see for yourself.
EEMBC Energy Benchmark Results for the STM32:
- 535 ULPMark-CP
- 149 ULPMark-PP
- 133000 SecureMark-TLS
Those double-take-inducing power consumption numbers are possible thanks to innovative new features on the STM32U5 like low-power background autonomous mode (LPBAM) that are especially relevant for local sensor monitoring. LPBAM provides direct memory access to peripherals while the CPU is asleep and no software is running so operations like peripheral reconfiguration and data transfers can be performed essentially for free.
Image source: https://www.st.com/resource/en/application_note/an5645-stm32u5-series-power-optimization-using-lpbam-stmicroelectronics.pdf
Industrial IoT sensor developers can use LPBAM to monitor sensors connected over the I2C, SPI, and UART interfaces. But they can also use the feature for single-sequence ADC conversions, which leverage a low-power timer PWM to trigger the STM32U5’s integrated 12- or 14-bit ADCs. At a 1 kHz sampling frequency, LPBAM ADC conversion can yield 90% current consumption savings over traditional run/sleep/stop operations.
Image source: https://www.st.com/resource/en/application_note/an5645-stm32u5-series-power-optimization-using-lpbam-stmicroelectronics.pdf
Image source: https://www.st.com/resource/en/datasheet/stm32u575ag.pdf
On the board, you’d access all this functionality via a do-it-all USB Type C Full Speed port that carries power and data, as well as the Arduino UNO v3-compatible ST Zio connectors that you can plug any number of off the shelf sensor shields into, as well as ST morpho extension pin headers for connecting scopes, logic analyzers, voltometers or other prototyping boards to the Nucleo. There’s also an onboard STLINK-V3E debugger/programmer with USB re-enumeration capability that eliminates the need for an external probe.
The STLINK-V3E debugger and programmer is also your ticket to the STM32U575ZIT6Q MCU’s TrustZone-enabled memory subsystem, which includes 786 Kb of SRAM and 2 MB of dual-bank Flash memory.
These and other onboard security mechanisms, like secure data storage with a hardware unique key, side-channel resistant AES encryption, and active tamper detection, have helped the STM32U575ZIT6Q achieve Arm PSA Level 3 and Security Evaluation Standard for IoT Platforms Level 3 certifications.
The same can be said of developing against industry standards, which if you’re designing an industrial sensor system, you will be.
The X-CUBE-STL functional safety package provided as a library in the STM32 Cube development environment provides a functional safety package for engineers who need to certify functions up to IEC 61508 safety integrity levels 2 or 3. The TÜV Rheinland-certified X-CUBE-STL includes a software-based diagnostic suite that uses a fault-injection methodology to detect random hardware failures in the CPU, SRAM, or Flash memory.
To access it you’ll need to sign an NDA and download the STM32CubeU5 MCU Package, which also includes reference code for things like Trusted Firmware M (TF-M) in accordance with the Arm PSA security model and examples of features like LPBAM.
So, we’ve come full circle and given you everything you need to get started build an Industrial IoT sensor module of your own courtesy ST Micro’s STM32U5 NUCLEO-144 evaluation board. Now you just need to get one, which will cost you just $22.54 per unit — not bad at all.
But as always, you can enter the raffle below to test your luck and win this board right here, and we’ll ship it to you anywhere in the world for free.
As always, thanks for watching. Good luck on what should be a simplified industrial IoT sensor system deployment, and we’ll see you next week on Dev Kit Weekly.
