Silicon Witchery Releases Development Board Integrating Nordic SoC and Lattice FPGA

Swedish embedded module supplier Silicon Witchery has released a very compact module, the S1, designed to connect a Nordic Semi nRF52840 to the most space-constrained projects, which also integrates a Lattice iCE40 field-programmable gate array (FPGA).

“Designed for efficient AI on the smallest edge devices,” Silicon Witchery claims of its combination of microprocessing and FPGA devices. “The S1 is designed to simplify your design and save you months of RF HDI [radio frequency high-density interconnect] layout. The S1 is a combination of four key components that are essential for developing tiny battery-powered products. It meets the demanding algorithms required by the application while consuming the least amount of power possible.”

Although the S1 module measures only 11×6 mm (about 0.43×0.24 inches), it includes four key blocks: a power management integrated circuit (PMIC) with a buck-boost converter and support for low-voltage regulators and battery charging functions; 32Mb external SPI flash for storage; a Nordic nRF52840 system-on-chip with a 64MHz Arm Cortex-M4 microprocessor; and a Lattice iCE40 FPGA with 5k LUTs and dedicated DSP cores.

Silicon Witchery claims that the microprocessor and FPGA can run always-on inference tasks at the edge while consuming as little as 75µA of power. Meanwhile, the integrated antenna provides wireless connectivity via Bluetooth 5.2 with long-range and Thread support. Overall, the module includes two general-purpose input/output (GPIO) pins from the nRF52 with analog-to-digital conversion (ADC) and low-power wake-up support, and another eight GPIO pins from the FPGA including I2C, I3C, SPI, and USB, as well as three adjustable Vout rails with up to 5.5V buck or boost.

In addition to the module itself, Silicon Witchery has released two development kits: the S1 Popout Board, which provides IO functionality configuration for the module, a debug port for the Cortex microprocessor, and a port for a LiPo battery and a StemmaQT/Qwiic compatible port to support external sensors. And the S1 ECG Kit, which uses the module to drive a low-power three-probe electrocardiograph with an integrated LiPo battery and onboard LEDs.