This week’s EYE ON NPI (video) is your best buddy for broadband, it’s Nordic Semiconductor’s nRF7002 Companion IC, a wireless add-on chipset designed for the Nordic Semi nRF52 and nRF53 ARM+Bluetooth and nRF91 ARM+Cellular to act as a WiFi peripheral.
With the addition of the nRF7 series, Nordic now covers the three most popular wireless transports: Bluetooth LE, LTE Cellular, and WiFi! This is a pretty big deal, because it’s their first foray into WiFi technology, so we expect that there will be more integration in the future.
The nRF7002 is a standalone chip, which requires only a few passives and an antenna, that performs the low-level interfacing to communicate with WiFi networks. Data is transferred back and forth between the nRF7 and host processor using SPI or QSPI – for higher speeds! At this time, it seems like the driver is only available via the Nordic SDK and using Zephyr RTOS – both of which would be good options because the WiFi stack lives on the host chip which means an SSL implementation which can require significant RAM and Flash. You’ll also need to store the chip patch firmware blob and transfer it over SPI on boot – again requiring storage or flash memory.
This setup reminds us a lot of the first Nordic chipset we used: the nRF8001 – which, hey, sounds kinda similar to the nRF7002 no? That chip provides a BLE interface over SPI communication. The nRF8001 was extremely early in the BLE product development cycle, but was simple enough that an Arduino UNO with 2KB of SRAM and 32KB of flash could suddenly pop into the BLE wireless space and implement any profile.
After successfully launching the ‘8001, Nordic followed it with the nRF51822, which likely had the same radio circuitry but stapled to a ARM Cortex M0. To be honest, we don’t talk about the nRF51, because the nRF52 and nRF53 series is available now and both are a lot roomier. We only mention this history to put some context into your first question – “why did Nordic make a standalone chip instead of integrating it into one their existing core designs” – because they’ll probably do that in the next generation after working out any bugs.
OK, but that hasn’t happened yet as of this writing, so why use this chip instead of an integrated WiFi core? Well, one thing is you may want to connect to 5GHz networks, which the nRF7002 supports, in addition to 2.4GHz, and you may need a processor with specific peripherals or quantity of GPIO or speed, or you’re already using the nRF53 or nRF91 chipset. That’s when the nRF7002 is going to shine. Nordic is also known for really good and complete SDK’s for nicely documented and supported peripherals with excellent low-power numbers.
For a fast start, grab the NRF7002-DK eval board that you can pick up with has an nRF53, JLink interface, antenna ports, and other accessories for quick bringup of a dual-BLE-WiFi design.
It’s still pretty early, but we can expect to see tinned modules come out into the market soon. For example Fanstel products are stocked at Digi-Key and it looks like they’re working on a few nRF7002 options.
For software, it’s also pretty early, since this is a new chip. There are lots of examples in the nRF SDK and also example code on the Nordic developer blog for MQTT connection.
Friend-of-the-fruit Golioth has a quickstart on how to use the nRF7002 to connect to their cloud for pub-sub and RPC currying. You can also use Nordic’s free apps for provisioning over BLE or Cellular.
If you want to add the nRF7002 to your design, now’s the time to check it out because Digi-Key has lots of the Nordic nRF7002 in stock right now for immediate shipment! Order today to get full WiFi 6 support into your next core design by tomorrow afternoon, with a powerful front-end chip that supports dual bands and antenna co-existence.