Nordic nRF52840

Executive summary

• The nRF52840 is a SoC from Nordic Semiconductor with an ARM Cortex-M4F core at 64 MHz, 1 MB of Flash, and 256 KB of RAM, focused on very low-power wireless connectivity. If you're new to the field, start with what IoT is and what it's for.
• Its multiprotocol radio supports Bluetooth Low Energy (BLE) 5, IEEE 802.15.4 (the foundation of Zigbee, Thread, and Matter), ANT, and proprietary 2.4 GHz RF.
• It is the go-to chip when power consumption rules the design: wearables, coin-cell sensors, Matter/Thread devices, and certified commercial BLEBTermBluetooth Low Energy (BLE)Bluetooth Low Energy (BLE) is the low-power variant of Bluetooth, for sending small amounts of data intermittently with minimal battery. It dominates wearables and proximity. Maintained by the Bluetooth SIG.View profile products.
• Compared with the ESP32, the nRF52840nTermnRF52840The nRF52840 is a Nordic Semiconductor SoC with a Cortex-M4F and ultra-low-power multiprotocol radio (BLE 5 and IEEE 802.15.4), a basis for many Matter/Thread devices.View profile wins on power consumption and a mature 802.15.4 radio, but it has no Wi-Fi and its learning curve (nRF Connect SDK / Zephyr) is steeper.
• It comes with native USB, an Arm CryptoCell-310 (hardware crypto), and official support for Nordic's Matter SDK.
• Don't use it when: you need integrated Wi-Fi (use the ESP32), cellular connectivity (NB-IoT), or long-range LoRa (use the nRF9160 or the STM32WLHardwareSTM32WLTechnical guide to ST's STM32WL: a SoC with a sub-GHz LoRa radio on the same chip, Cortex-M4/M0+ and low power for LoRaWAN nodes.View profile, respectively).

What the nRF52840 is

The nRF52840 is the top of the line in Nordic SemiconductorCompanyNordic SemiconductorSpecialist in low-power wireless connectivityView profile's nRF52 series, a Norwegian manufacturer that specializes in ultra-low-power radios. Where Espressif (the ESP32) dominates the Wi-Fi/maker world, Nordic dominates commercial BLE and, increasingly, Thread and Matter.

Its key specifications:

What defines the chip is not raw power (a modest Cortex-M4F), but the balance between a multiprotocol radio and minuscule power consumption. A BLE sensor with an nRF52840 and a coin cell can run for months or years.

The multiprotocol radio: why it matters

The great value of the nRF52840 is that its radio covers the two major short-range IoTITermIoT (Internet of Things)The IoT (Internet of Things) is the network of physical objects with sensors, software and connectivity that collect and exchange data and act autonomously.View profile ecosystems with a single chip:

• BLE 5: with all the modern features (Coded PHY for long range, 2M PHY, extended advertising). Ideal for wearables, beacons, and products that pair with a phone.
• IEEE 802.15.4: the physical layer on which Zigbee, Thread, and therefore Matter run. This makes the nRF52840 one of the go-to chips for Matter over Thread devices.

That a single SoC can be a BLE sensor today and a Matter device tomorrow—even both at once with Nordic's multiprotocol support—is what makes it so attractive to manufacturers betting on the Matter ecosystem without giving up BLE for onboarding.

Real-world use cases

Many certified commercial modules (from Fanstel, Raytac, u-bloxCompanyu-bloxPositioning (GNSS) and cellular communication modulesView profile, Laird) integrate the nRF52840 precisely to skip RF recertification, an enormous saving of time and money compared with designing the radio from scratch.

nRF52840 vs ESP32: the comparison everyone makes

It's the inevitable question. There's no absolute winner: it depends on the project.

Choose the nRF52840 when: power consumption is critical, you need commercial-grade certified BLE, or you're building Thread/Matter devices. Choose the ESP32 when: you need Wi-Fi, more compute power, or the maker/ArduinoCompanyArduinoOpen source hardware and software platform for makersView profile ecosystem and the low price matter more than power consumption.

When NOT to use the nRF52840

• You need Wi-Fi: the nRF52840 doesn't have it. Use the ESP32 or an nRF with a Wi-Fi companion.
• Cellular connectivity: for NB-IoT/LTE-MLProtocolLTE-MCellular IoT with mobility and voiceView profile, Nordic has the nRF9160 (with an integrated cellular modem), not this chip.
• Long-range LoRa: for LoRaWAN, use a SoC with a sub-GHz radio such as the STM32WL.
• Heavy compute or edge AI: a Cortex-M4F at 64 MHz falls short against an ESP32-S3 with acceleration or a Raspberry PiCompanyRaspberry PiSingle-board computers and RP2040/RP2350 microcontrollersView profile.
• Quick prototyping without a curve: if you want Arduino and nothing more, the ESP32HardwareESP32Dual-core WiFi + BT/BLE SoC at €-tier priceView profile is friendlier; the nRF Connect SDK is more professional but more demanding.

The development ecosystem: nRF Connect SDK and Zephyr

This is the biggest practical difference from the ESP32. Nordic bets on the nRF Connect SDK, built on the Zephyr RTOS (a Linux Foundation project). It's a professional, powerful, and well-documented environment, but with more initial friction than Arduino's setup()/loop().

Development options:

• nRF Connect SDK (Zephyr): the official and recommended path for a commercial product. A CMake/west-based build system, certifiable BLE and Matter stacks.
• Arduino (Adafruit nRF52 core): for rapid prototyping on boards such as the AdafruitCompanyAdafruitOpen hardware, breakouts and learning for makersView profile Feather nRF52840 or the SparkFun Pro nRF52840 Mini.
• Pure Zephyr: if you already work with Zephyr on other chips.

Example: a BLE peripheral with Zephyr (nRF Connect SDK)

#include <zephyr/kernel.h>
#include <zephyr/bluetooth/bluetooth.h>
#include <zephyr/bluetooth/gap.h>

static const struct bt_data ad[] = {
    BT_DATA_BYTES(BT_DATA_FLAGS, BT_LE_AD_GENERAL | BT_LE_AD_NO_BREDR),
    BT_DATA(BT_DATA_NAME_COMPLETE, "nRF52-Sensor", 12),
};

void main(void) {
    bt_enable(NULL);
    bt_le_adv_start(BT_LE_ADV_CONN, ad, ARRAY_SIZE(ad), NULL, 0);
    /* the device now advertises and accepts BLE connections */
}

For faster prototyping, the same chip on a Feather nRF52840 with the Arduino core uses the well-known Adafruit_Bluefruit library, closer to the ESP32 style.

Debugging tools

Nordic offers nRF Connect for Desktop and the nRF Connect for Mobile app, which is the de facto standard for inspecting any BLE device, not just its own. Programming is done over SWD with a J-Link (integrated into the official dev kits such as the nRF52840 DK).

Pros and cons

Pros

• Minuscule power consumption: ~1.5 µA in sleep, ideal for a coin cell.
• Mature multiprotocol radio: BLE 5 + 802.15.4 (Thread/ZigbeeProtocolZigbeeVeteran 2.4 GHz mesh — backbone of many smart home hubsView profile/Matter) on one chip.
• Hardware security: CryptoCell-310 (AES, ECC, RNG).
• Native USB: for convenient dongles and bootloaders.
• Suitable for a commercial product: pre-certified modules, official Matter support.

Cons

• No Wi-Fi: limits cases that require a direct, high-throughput IP connection.
• Learning curve: the nRF Connect SDK/Zephyr is professional but demanding.
• Modest compute: a Cortex-M4F at 64 MHz, no heavy edge AI.
• Higher price than the ESP32 at the individual chip level.
• Smaller maker community than the ESP32's (though the professional one is solid).

Primary sources

• Nordic Semiconductor — nRF52840 Product (accessed: 2026-05)
• nRF52840 Product Specification (datasheet) (accessed: 2026-05)
• nRF Connect SDK Documentation (accessed: 2026-05)
• Zephyr Project — the RTOS underlying Nordic's SDK