Nordic Semiconductor has introduced a new board to accelerate development with their Wi-Fi 6 companion chip. Available to ship today, the nRF7002 EK is a Wi-Fi 6 evaluation kit in an Arduino form factor. It complements Nordic’s Bluetooth (nRF52/nRF53) and cellular (nRF91) microcontroller IoT development platforms.
Nordic’s nRF70 Series are Wi-Fi 6 companion ICs with features like Target Wake Time (TWT), Orthogonal Frequency Division Multiple Access (OFDMA), BSS Coloring, and SSID-based locationing. There are three variants in the nRF70 family.
Comparing nRF70 variants (📷: Nordic Semiconductor)
The nRF7002 and nRF7001 have the same core features, with the nRF7002 supporting 2.4 and 5 GHz bands, while the nRF7001 only operates on the 2.4 GHz band. The nRF7000 is also a 2.4 GHz-only radio. However, it does not provide data communication. It primarily provides SSID data for determining location. All three chips are available in a 6×6 millimeter QFN-48 package.
nRF7002 DK (📷: Nordic Semiconductor)
Previously, Nordic launched the nRF7002 Development Kit. Compared to the new EK, that much larger board contains an nRF5340 host SoC which provides Bluetooth 5.0 and Bluetooth Low-Energy (BLE) connectivity, additional hardware for programming/debugging, and breakouts for measuring current.
The nRF7002 EK’s PCB is shaped like an Arduino Uno shield with compatible pin-spacing. The board contains an nRF7002 IC with a dual-band antenna and voltage regulator for a 5-volt supply. There is also a SWF port for measuring RF signals with a spectrum analyzer.
Nordic intends the nRF70 Evaluation Kit for use with the RF52840 DK, nRF5340 DK, and nRF9160 DK boards. However, the EK board can work with any host processor that supports SPI or QSPI interfaces with IO signaling between 1.8 and 3.6 volts. In other words, it is not 5-volt IO compatible.
nRF7002 EK (📷: Nordic Semiconductor)
The header pins on the bottom of the nRF7002 EK connect to sockets on the host board. The top has unpopulated surface mount pads. These allow you to place additional pins/sockets or keep them empty as test points. The pins connect to the nRF70’s SPI/QSPI interface, power supply enable pins, and coexistence port.
Functional coexistence block diagram (📷: Nordic Semiconductor)
Coexistence (COEX) enables multiple radios to work seamlessly together. For example, when combined with an SoC that supports 2.4 GHz-based protocols like BLE, Thread, or ZigBee, you do not want to operate simultaneously with the Wi-Fi radio. In production designs, the COEX interface also allows the sharing of the same chip antenna between radios.
Programming the nRF7002 EK is straightforward when using Nordic’s nRF Connect SDK. It comes with several sample projects for utilizing the nRF70 with nRF SoCs. Additionally, in software, you can disable (or ignore) features of the nRF7002 to emulate the operation of an nRF7001 or nRF7000.
Related to this introduction, Nordic has posted a driver for the nRF70. It is a reference implementation (provided as-is) to help evaluate the nRF70 in Linux environments. The code has been tested on a Raspberry Pi 4 B running Ubuntu 22.04 LTS. While the nRF7002-EK does not connect directly to a Raspberry Pi, the headers should make such a connection possible.
nRF7002 EK (📷: Nordic Semicondcutor)