The nrf5340-DK from Nordic Semiconductors just arrived in the mail. Let’s have a look at what sets it apart from the nrf52-DK featuring an nrf52832!
The Dev-Board
The differences
Looking at the two boards side-by-side, the first thing we notice is the bigger size of the dev-board. This is probably mostly due to the increased number of GPIO pins the nrf5340 supports. It features twice as many I/O pins as the nrf52832 (2 ports of 32 pins instead of just 1).
The nrf53-DK also comes with the possibility to run it on a Li-po battery and the power source can be chosen accordingly with a switch. In addition, the nrf53-DK also has a USB connector that is directly interfaced to the target MCU. The ESD protection circuit features a PRTR5V0U2X, which looks interesting and will probably be on the BOM of my next PCB featuring an USB connector, but I digress…
The commonalities
For the rest, the two boards have a lot in common, they feature an NFC connector as well as a PCB antenna and SMA connectors for adding an external antenna. Both have debug headers that can be used to program and debug external devices, and they also both have current measurement support, which comes in handy if we need to do current profiling of applications.
The nrf5340-DK actually features two nrf5340s! Here, the first one (U1) is the one that’s actually connected to all the peripherals, on the DK. The second one (U2) is only used for programming and debugging (U2). Nordic calls this second MCU the interface MCU .This is similar to the nrf52-DK, however the older revision of the nrf52-DK I am using still features a Microchip ARM-MCU (ATSAM3U2CA) as an interface MCU, while on newer revisions you’d also find an nrf5340.
As usual, the board comes in an Arduino compatible design. Arduino shields are easily applied and used for prototyping. LEDs and Buttons can be found on both, even though they aren’t interfaced to the same pins.
The Documentation
I have to say, when it comes to documentation, Nordic is on top of the game. They provide a lots of detail while not overloading you with information. A single ZIP-File containing all the production files is available for download, including gerber files. Even pick-and-place files are in there so these development boards are essentially open source hardware! There is also a pdf schematic in the ZIP-file and we find everything with a simple Google-Search. (Here for the nrf52-DK and here for the nrf53-DK) That’s top of the line and I can’t see a big difference between the nrf52-DK and the nrf53-DK. Keep that up Nordic!
The Processor
Now for the heart and brain of the boards, the processors. The nrf5340 is quite a lot beefier than the nrf52832.
Cores
Instead of a single processor, the nrf5340 features two Arm® Cortex®-M33 processors, where one is marketed as the “Application core” and one as the “Network core”. The application core comes with a lot of debug-ability supporting different Trace-interfaces. It also contains a Arm TrustZone CryptoCell™-312 security subsystem that allows for hardware accelerated computation of common cryptographic algorithms and PRNG.
Memory
While the nrf52832 only has measly 512kB flash and 64kB of RAM, the nrf5340 has 1MB of flash memory and 512(!)kB of RAM – now that’s an improvement.
Peripherals
In terms of peripherals, there isn’t too much of a difference between the two, as both feature the common usual suspects – SPI, I²C, I²S and UART. The nrf5340 has the already mentioned USB-support and also supports QSPI. Everything can be interfaced using the programmable peripheral interconnect so we aren’t forced to use certain pins for certain functions.
Wireless communication
Finally, in addition to the nrf52’s BLE, BL Mesh and ANT™ support, the nrf5340 also supports IEEE 802.15.4, which makes it ready for Matter, Thread and Zigbee, so it is even more applicable for the IoT devices of the coming decade.
Conclusion
The nrf52-DK and nrf53-DK have commonalities and differences. Both devices have their place and knowing the differences is key in knowing when to use which device. In general, these devices are quality products and if you can get away with an nrf52832, it should definitely be used. Having both to my disposal enables me to quickly evaluate solutions and find the most appropriate device for the task.