Stefano Viola's NiCE5340 SoM Pushes Miniaturization Boundaries
nRF53 Bluetooth SoC, iCE40 FPGA, nPM1100 battery charger, and 10 sensors are packed into this 16x29 mm PCB.
Design challenges are a fantastic way to hone your skills and acquire new ones. Stefano Viola, an experienced electronics engineer, sought a miniaturization challenge. This journey led to a system-on-module (SoM) named NiCE5340, an ingeniously tiny PCB that merges a Bluetooth SoC, FPGA, and a wide array of sensors.
"I had been wondering for some time what would be the result of combining a powerful low-power MCU with an equally versatile low-power FPGA." —Stefano Viola
Viola packed many integrated circuits (ICs) onto NiCE5340's 16- by 29-millimeter printed circuit board. A Nordic Semiconductor nRF5340 system-on-chip (SoC) is at the center. Next to it is a Lattice semiconductor iCE40 Ultra Plus FPGA. At least 11 sensors complement these two processing chips.
The nRF53 SoC contains two Arm Cortex-M33 processors and a 2.4 GHz radio. The RF block supports Bluetooth 5.4, Bluetooth LE (BLE), Thread, Zigbee, and proprietary protocols. An nPM1100, also from Nordic, provides power management and LiPo battery charging.
Lattice's iCE40 FPGA has gained notoriety because of the open source tools that generate bitstreams for these parts. Viola connected the iCE40 to the nRF53 via Quad-SPI (QSPI) and I2C. Its IO pins break out to pads on the back.
While the NiCE5340 incorporates nearly every sensor type in its design, Viola acknowledges that not all of them (together) may have a practical application. However, the potential uses of these sensors are vast, ranging from environmental monitoring to health tracking, making the NiCE5340 a versatile and adaptable PCB.
- 6DOF IMU: LSM6DSMTR (STMicroelectronics)
- Biosignal converting unit: AS7057-BWL (Osram)
- Magnetometer: MMC3630KJ (Memsic)
- SAR sensor (touch): SX9328ICSTRT (Semtech)
- PDM MEMS MIC: ICS-41351 (TDK)
- Humidity/temperature: SHTC3 (Sensirion)
- Haptic driver: DRV2605LYZF (Texas Instruments)
- RGB IR color sensor: BH1749NUC-E2 (Rohm)
- Barometric pressure sensor: DPS310XTSA1 (Infineon)
- Charge/discharge current measurement: INA231AIYFDT (Texas Instruments)
- RTC: MAX31342EWA+T (Analog Devices)
If you inspect the small board closely, you might notice no obvious way to program either the nRF53 or the iCE40. Since the board has an onboard chip antenna and an MHF4 connector for an external antenna, one option is to program the nRF53 over-the-air (OTA). The FPGA might be programmable OTA via the nRF53 as well. However, Viola still needs to test this capability.
The PCB's back has land-grid-array (LGA)-style pads. Viola also designed a carrier board to attach the NiCE5340 PCB. The pads break out many more signals from the SoC, including the nRF53's native USB port. A flat ribbon cable connector could also support the nRF53's NFC antenna!
As Viola conceived this board as a design exercise, the long-term intentions are yet to be fully defined. The NiCE5340 GitHub repository already hosts a PDF schematic, and Viola says it will eventually include code examples. If you're eager to explore this board's potential or have suggestions for its design, reach out to Stefano Viola via this LinkedIn post.