Nordic's first Wi-Fi-capable chip was the nRF7002. This companion IC adds Wi-Fi 6 at 2.4 and 5 GHz to any microcontroller with an SPI or QSPI interface. The nRF7002 DK (development kit) provides a demonstration platform for the chip and Nordic's nRF53 Arm + BLE SoC. In this video, James gives an overview of the nRF7002 and its design kit. Then, he demonstrates some current and RF measurements. Last, he compares the nRF7002 to the DK, EK, and EB.
Watch the Video:
Downloads and Links | Bill of Material | Discussion
Most people know Nordic Semiconductor from their system-on-chip (SoC) products that combine Arm CPUs with a 2.4 GHz radio. The nRF24 is a popular "serial link" radio set. Their nRF51, nRF52, nRF53, and nRF54 SoC feature Bluetooth, Bluetooth Low Energy (BLE) support, and other industry standard 2.4 GHz protocols. The one missing, until recently, was Wi-Fi! Nordic addressed this shortcoming by introducing the nRF7002--a dual board (2.4 and 5.0 GHz) Wi-Fi 6 companion IC.
Currently, there are three SoCs in the nRF70 family. The nRF7002 is the full-featured chip, while the nRF7001 variant does not include the 5.0 GHz radio. A slightly different member of this family is the nRF7000. It can actively or passively scan SSIDs on 2.4 GHz networks to help determine a device's location. However, it does not support any data modes. All three chips come in a QFN package. To make working with the ICs easier, Nordic offers several boards with the nRF7002.
nRF7002 Development Kit (DK)
The nRF7002 DK (Development Kit) is a highly integrated development platform with three large ICs. One of those chips is, obviously, an nRF7002. It connects to two on-board antennas. One is for 5.0 GHz, and one is for 2.4 GHz. The nRF70 can control which antenna it uses with an RF switch.
Another chip is what Nordic calls a "host controller." It is an nRF53840 SoC. This IC contains two Arm-Cortex M33 cores and a 2.4 GHz Bluetooth 5.4 radio. The chip dedicates one core to network operations and the other to your application. Its radio connects to the same 2.4 GHz antenna as the nRF7002 but through another RF Switch.
One of the nRF7002's valuable features is the Co-Existence (COEX) interface. This 3- or 4-wire interface enables the nRF7002 and Host Microcontroller to determine which wireless radio has access to which antenna!
The nRF53 microcontroller features a rich set of interfaces available on their GPIO pins. The nRF7002 DK features several pin headers, including Arduino Uno-style headers, so you can access the IO pins. However, remember that the nRF53's IO is NOT 5-volt tolerant!
On the left side of the board is a third IC. It is another nRF53 microcontroller. Nordic calls this one an "Interface MCU." It provides on-board programming and debugger capability through J-Link for the host nRF53. The two microcontrollers also share UART pins so that you can pass serial messages back to the PC through a single USB connection.
The nRF7002 DK has several input options for power and methods for measuring current consumption. By default, the programmer's USB port can power the board. However, jumper pins let you change this configuration. They also allow you to connect tools like the nRF Power Profiler Kit II (PPK2).
Coding for the nRF7002
Nordic supports the nRF7002 through its nRF Connect SDK. You can install the SDK using their nRF Connect for Desktop and Toolchain Manager. James showed how the SDK works with Microsoft's VSCode for code development.
Inside VSCode, you can find shortcuts to an application creator, code samples, and building tools after installing the nRF-specific extensions. James shows a simple example of loading the Wi-Fi Shell example, building it, and flashing it to the nRF7002 DK. (He skipped the initial configuration of selecting the nRF7002 DK board because he did that before recording the video!)
Nordic built the Wi-Fi Shell example with the Zephyr real-time operating system (RTOS). So, you are greeted with a UNIX-like shell prompt when you open a serial port to the nRF7002 DK. The most helpful command is called "wifi." It lets you connect to an access point, change the chip's mode, and various other functions.
James uses it to connect the nRF7002 to a 5 GHz Wireless Access Point!
Measuring Current
Above the debugger USB port is a pin set connecting to the nRF7002. Another set, after a minor board modification, allows you to use a second PPK2 to measure the host nRF53 and nRF70 at the same time!
In the video, James demonstrates how the PPK2 can measure the nRF70's current consumption while idle, transmitting, and even asleep! (James previously covered the PPK2 in a video measuring dynamic current consumption.)
nRF7002 RF Measurements
The Wi-Fi Radio Test sample application provides a similar command prompt to the shell sample. However, it has two wifi-specific commands. One lets you program the one-time programmable registers in the nRF7002. And the other controls the RF radio.
James connects the nRF7002 DK to a spectrum analyzer through an "SWF port." These are a combined connector and switch port from Murata. In this design, they disconnect the chip antennas from the nRF7002. They allow you to measure the "TX signal" or inject an "RX signal" into the IC.
The first measurement James shows is a simple frequency sweep. Then, he used the radio test program to change the Wi-Fi channel to 3 and demonstrated that the carrier was at 2.422 GHz, as expected.
The second measurement shows how to use the built-in power amplifier to adjust the transmit level of the signal. Using saved traces, James showed three signals with about 10 dB between each.
Three boards with nRF7002
Currently, Nordic offers three boards with the nRF7002. Until this point in the video, James focused on showing the nRF7002 DK. This full-featured board is excellent for starting with the nRF53 SoC and the nRF70 Wi-Fi 6 companion IC.
A smaller nRF7002 EK, or evaluation kit, comes in an Arduino Uno shield form factor. This board contains only the nRF7002, antenna, and supporting circuit. Nordic intends you to connect it to other nRF development kits to add Wi-Fi 6. However, you could use it with just about any SPI or QSPI interface microcontroller.
James does point out that while this board is mechanically compatible with Uno shields, it is not electrically compatible. The nRF7002 IC is not 5 volt tolerant!
The third board is the nRF7002 Expansion Board. It serves two purposes. The primary purpose is to plug into the Thingy:53--an all-in-one IoT development platform. The Thingy:53 contains a nRF53 SoC, sensors, and firmware for connection to the Edge Impulse platform.
You can also use the EB standalone by snapping off the Thingy's edge connector. Then, you can solder the remaining PCB to a custom board with castellated edges. The benefit of this approach is adding Wi-Fi 6, including 5 GHz support, to any custom PCB without working about all that RF ... stuff!
Downloads and Links:
- Product Review: Nordic nRF7002 Wi-Fi DK Roadtest Product Review by redcharly
- Product Review: RoadTest of the Nordic nRF7002 Wi-Fi DK by Fred27
- Product Review: Nordic nRF7002-DK Review by vmate
- Product Review: nRF7002 WiFi 6 review and building wifi 6 matter accessory by ss_shrenik
- Webinar:: Beginner's Guide to Embedded ML with Nordic Thingy:53 and Edge Impulse Studio
- User Guide: nRF7002 DK User Guide
- Nordic nRF7002 EK Adds Wi-Fi 6 Capability to IoT Prototypes as an Arduino Shield
- nRF7002 Expansion Board Boosts Nordic Thingy:53's Connectivity with Wi-Fi 6
Bill of Material:
| Product Name | Manufacturer | Quantity | Buy Kit |
|---|---|---|---|
| nRF7002, RF Transceiver, 2.401 GHz to 5.895 GHz, 86 Mbps,-98.6 dBm , 21 dBm Pout, 2.9V to 4.5Vsupply, QFN-48 | Nordic Semiconductor | 1 | Buy Now |
| nRF7002-EK, Evaluation Kit (Shield Style) | Nordic Semiconductor | 1 | Buy Now |
| nRF7002-DK, Design Kit | Nordic Semiconductor | 1 | Buy Now |
| nRF7002-EB, Evaluation Board | Nordic Semiconductor | 1 | Buy Now |
| Thingy:53 IoT Prototyping Platform | Nordic Semiconductor | 1 | Buy Now |
Additional Parts:
| Murata MXHS83QE3000 SWF to SMA Adapter |
