EYE on NPI: Nordic nRF54L15 Wireless SoC and Development Kit EYEonNPI

Adafruit Industries

This week's EYE ON NPI is another great step forward in Bluetooth Low Energy development, it's Nordic's new nRF54 series (https://www.digikey.com/en/product-highlight/n/nordic-semi/nrf54l15-multiprotocol-soc) and nRF54L15 Wireless SoC Development Kit (https://www.digikey.com/en/product-highlight/n/nordic-semi/nrf54l15-wireless-soc-development-kit). This is the heir-apparent to the popular nRF52840 (https://www.digikey.com/en/products/detail/nordic-semiconductor-asa/NRF52840-CKAA-R/15929796) series chip which we know and love so much. The nRF54 series comes in L and H variants, for 'low' and 'high' power, but even the L series is a step up, with Cortex M33 running at 128MHz, and up to 1.5MB ReRAM (https://en.wikipedia.org/wiki/Resistive_random-access_memory) / 256KB SRAM. The H series is a whole new ball-game with dual M33 running at 320MHz, 2MB of ReRAM and 1MB of SRAM plus upgraded peripherals. Wow, the nRF series has come such a long way from the baby-steps of the SPI-peripheral nRF8001 (https://www.digikey.com/en/products/detail/nordic-semiconductor-asa/NRF8001-R2Q32-T/4626390) to the early ARM Cortex M0 plus BLE combo chip, the nRF51 (https://www.digikey.com/en/products/detail/nordic-semiconductor-asa/NRF51822-QFAB-R7/4626396). We still use that nRF51 in many of our Bluetooth LE boards like the Feather 32u4 and M0 (https://www.digikey.com/en/products/detail/adafruit-industries-llc/2995/5823444), also as a SPI-peripheral-to-BLE converter. The next big upgrade was the nRF52832 (https://www.digikey.com/en/products/detail/nordic-semiconductor-asa/NRF52832-QFAB-R/6051565) which bumped the processor from an M0 to an M4, but didn't do a huge bump to the Flash or SRAM compared the nRF51. The big leap after that was the nRF52840 which is still an amazing chip: USB peripheral means you can use this chip as the main processor, and it can do all your processing, user interface, sensor reading and wireless communication with only a few passives to support it. There was an nRF5340 released about two years ago (https://www.digikey.com/en/products/detail/nordic-semiconductor-asa/NRF5340-CLAA-R/14323741) but much like Windows releases, we tend to skip every other chip. We happened to check digikey.com/new yesterday and saw the nRF54L (https://www.digikey.com/short/zf8pz0cr) series pop up, which is exciting as it was pre-announced about a year ago (https://www.youtube.com/watch?v=XG8bRNaNHrg) and is now shipping to customers! The nRF54L (https://www.digikey.com/short/zf8pz0cr) comes in three variants, which is not surprising because we've seen earlier chips come in 'lite' versions that cut pricing by having less flash or RAM. All variants have a 128MHz Cortex M33 with a RISC-V co-processor, and a BLE stack. One interesting thing we noted, is that instead of flash memory, which is big and expensive and hard to do with modern fab processes, the nRF54 uses ReRAM (https://en.wikipedia.org/wiki/Resistive_random-access_memory) which is non-volatile and uses memristor technology, which is pretty cool! The nRF54 series supports BLE 6, one new capability is channel sounding (https://en.wikipedia.org/wiki/Channel_sounding) which will improve the ability of phones to locate 'find my' tags that have become such a popular usage for the nRF chipset. Traditionally, the nRF52 chips in these tags use RSSI to measure approximate distance. There's been some improvements on the technology such as Angle-of-Attack that was introduced in BLE 5.1 (https://www.youtube.com/watch?v=EosGQtGioiY) but now with a broad-sprectrum burst it's looking like some of the lessons from UWB (https://blog.adafruit.com/2024/03/15/sera-nx040-ultra-wide-band-and-bluetooth-combo-module-eyeonnpi-digikey-digikey-lairdconnect-adafruit/) are being integrated to the BLE specification to improve item location. The nRF54L series is launching with the L15 variant (https://www.digikey.com/short/rd9fr19f), that's the one with the most memory, so it's a good start: once you have your design settled you can transition to the smallest chip you can get away with. They're coming into stock shortly so sign up at DigiKey to get notified when the package you're looking for arrives. While you wait, you can order up one of the nRF54L15-DK (https://www.digikey.com/short/qvhqv85q) dev kits, which are only $39 and in stock right now for immediate shipment. Order today and you'll get everything you need to start developing the nRF54 (https://www.nordicsemi.com/Products/Development-hardware/nRF54L15-DK) - a built in debugger, power management chip, broken out GPIO, user buttons and LEDs. While you wait for your dev kit to arrive, you can start thinking about the nRF54H series (https://www.nordicsemi.com/Products/nRF54H20) which is the high-end chip with dual M33 running at 320 MHz, 1 MB of SRAM, 2MB of ReRAM , high speed USB and I3C support (https://www.youtube.com/watch?v=hC4zkvdVag4)!