Bluetooth Low Energy (Bluetooth LE, colloquially BLE, formerly marketed as Bluetooth Smart) is a wireless personal area network technology designed and marketed by the Bluetooth Special Interest Group (Bluetooth SIG) aimed at novel applications in the healthcare, fitness, beacons, security, and home entertainment industries. It is independent of Bluetooth BR/EDR[clarification needed] and has no compatibility, but BR/EDR and LE can coexist. : Wikipedia
Bluetooth Low energy is one of the driving technology for expansion of internet of things applications, near future billions of devices will run BLE as communication medium. as demands are increasing more companies are coming with low cost BLE chip based or module based solutions.
Reason for more popularity of BLE as are given low cost, easy connectivity with Bluetooth based mobile devices, free gateway to internet.
BLE Applications:
- Beacons
- Remote controls
- Proximity tags
- Toys
- Low power sensors
- Wearable Electronics
- Asset tracking
Point’s to be consider while selection of BLE based IC’s are given below:
- Output power: If Output power is more, BLE signal will cover more distance but battery life degrades
- Rx Sensitivity: tells us the weakest signal that a receiver will be able to identify and process.
- Transmit Current: device current consumption during transmit cycle, it should be as low as possible
- Receive Current: device current consumption during receive cycle, it should be as low as possible
- Standby current: deep power down mode current rating
- Connectivity Peripherals: UART, SPI, I2C can be used to connect sensor devices
- Price: Price is play vital role in IOT development, user want more features in BLE based chip alongside low price
- Operating temperature:
STM32WB55CG:
The STM32WB55xx multiprotocol wireless and ultra-low-power devices embed a powerful and ultra-low-power radio compliant with the Bluetooth® Low Energy SIG specification v5.0 and with IEEE 802.15.4-2011. They contain a dedicated Arm® Cortex® -M0+ for performing all the real-time low layer operation. The STM32WB55xx devices are designed to be extremely low-power and are based on the high-performance Arm® Cortex®-M4 32-bit RISC core operating at a frequency of up to 64 MHz. The Cortex®-M4 core features a Floating point unit (FPU) single precision that supports all Arm® single-precision data-processing instructions and data types. It also
implements a full set of DSP instructions and a memory protection unit (MPU) that enhances application security.
The STM32WB55xx devices embed several mechanisms for embedded Flash memory and SRAM: readout protection, write protection and proprietary code readout protection. Portions of the memory can be secured for Cortex® -M0+ exclusive access. The two AES encryption engines, PKA and RNG enable lower layer MAC and upper layer cryptography. A customer key storage feature may be used to keep the keys hidden. The devices offer one fast 12-bit ADC and two ultra-low-power comparators associated with a high accuracy reference voltage generator. The STM32WB55xx devices embed a low-power RTC, one advanced 16-bit timer, one general-purpose 32-bit timer, two general-purpose 16-bit timers, and two 16-bit low-power timers. In addition, up to 18 capacitive sensing channels are available. The devices also embed an integrated LCD driver up to 8×40 or 4×44, with internal step-up converter.
Web Site: www.st.com/en/microcontrollers-microprocessors.html
Training Material: www.st.com/content/st_com/en/support/learning/stm32-education/stm32-moocs/STM32WB_workshop_MOOC.html
DA14531:
The DA14531 is an ultra-low power SoC integrating a 2.4 GHz transceiver and an Arm® Cortex-M0+ microcontroller with a RAM of 48 kB and a One-Time Programmable (OTP) memory of 32 kB. It can be used as a standalone application processor or as a data pump in hosted systems. The radio transceiver, the baseband processor, and the qualified Bluetooth® low energy stack is fully compliant with the Bluetooth® Low Energy 5.1 standard.
The DA14531 has dedicated hardware for the Link Layer implementation of BLE and interface controllers for enhanced connectivity capabilities. The BLE firmware includes the L2CAP service layer protocols, Security Manager (SM), Attribute Protocol (ATT), the Generic Attribute Profile (GATT), and the Generic Access Profile (GAP). All profiles published by the Bluetooth® SIG as well as custom profiles are supported. The device is suitable for disposables, wireless sensor nodes, beacons, proximity tags and trackers, smart HID devices (stylus, keyboards, mice, and trackpads), toys, and medical and industrial application.
Web Site: www.dialog-semiconductor.com/products/bluetooth-module-da14531-smartbond-tiny
Product Details: www.dialog-semiconductor.com/products/connectivity/bluetooth-low-energy/products/da14530-and-da14531
Training Material: www.dialog-semiconductor.com/done-in-a-day
ESP32-PICO-V3:
The ESP32-PICO-V3 is a System-in-Package (SiP) device that is based on ESP32 with ECO V3 wafer, providing complete Wi-Fi and Bluetooth® functionalities. It integrates a 4 MB SPI flash. At the core of ESP32-PICO-V3 is the ESP32 (ECO V3) chip, which is a single 2.4 GHz Wi-Fi and Bluetooth combo chip designed with TSMC’s 40 nm low-power technology. ESP32-PICO-V3 integrates all peripheral components seamlessly, including a crystal oscillator, flash, filter capacitors and RF matching links in one single package. Module assembly and testing are already done at SiP level.
As such, ESP32-PICO-V3 reduces the complexity of supply chain and improves control efficiency. With its ultra-small size, robust performance and low-energy consumption, ESP32-PICO-V3 is well suited for any space-limited or battery-operated applications, such as wearable electronics, medical equipment, sensors and other IoT products.
Web Site: www.espressif.com/en/support/documents/technical-documents
Product Details: docs.espressif.com/projects/esp-idf/en/latest/esp32/hw-reference/esp32/get-started-pico-kit.html
Training Material: Example codes are available in Visual Studio Code after installing ESP-IDF Add on or in Arduino IDE
nRF51822
The nRF51822 is a powerful multiprotocol single chip solution for ULP wireless applications. It incorporates Nordic’s latest best-in-class performance radio transceiver, an ARM® Cortex™ M0 CPU and 256kB/128kB flash and 32kB/16kB RAM memory. The nRF51822 supports Bluetooth® low energy (formerly known as Bluetooth Smart) and 2.4 GHz protocol stacks.
The new radio forms the basis of the nRF51822’s performance. The radio supports Bluetooth low energy and is on air compatible with the nRF24L Series products from Nordic Semiconductor. Output power is now scalable from a maximum of +4dBm down to -20dBm in 4dB steps. Sensitivity is increased at every level and offers sensitivity ranges (dependent on data rate) from -96 to -85dBm, with -93dBm for Bluetooth low energy.
The nRF51822 offers developers a clean separation between application code development and embedded protocol stacks. This means compile, link and run-time dependencies with the embedded stack and associated de-bugging challenges are removed. The Bluetooth low energy stack is a pre-compiled binary available from Nordic Semiconductor, leaving application code to be compiled stand-alone. The embedded stack interface uses an asynchronous and event-driven model removing the need for RTOS frameworks.
Web Site: www.nordicsemi.com/Products/Low-power-short-range-wireless/Bluetooth-low-energy
Product Details: www.nordicsemi.com/Software-and-Tools/Development-Kits/nRF51-DK
Training Material: infocenter.nordicsemi.com/pdf/nRF51_Development_Kit_User_Guide_v1.2.pdf
Comparison between STM32WB55CG vs da14531 vs ESP32-PICO vs nRF51822
| Part Number | STM32WB55CG | DA14531 | ESP32-PICO | nRF51822 |
| Marketing Status | Active | Active | Active | Active |
| Package | UFQFPN 48 7x7x0.55 | WLCSP 17 balls, 1.7 × 2.05, 0.5 mm, FCGQFN 24 pins, 2.2 × 3, 0.4 mm | LGA 48-pin, 7*7 mm | 6 x 6 QFN48 with 32 GPIOs 5 x 5 QFN32 with 16 GPIOs 2.48 x 2.46 WLCSP33 with 15 GPIOs |
| Core | Arm Cortex-M4 | Cortex – Mo+ | LX6 microprocessor | Arm Cortex-M4 |
| Operating Frequency (MHz) | 64 | 16 | 240 | 64 |
| Flash Size (kB) (Prog) | 1024 | External | 448 (16 MB Extern Flash) | 192 |
| RAM Size (kB) | 128 | 48 | 520 | 24 |
| Timers (16-bit) typ | 5 | 1 | 1 | |
| Timers (32-bit) typ | 1 | 2 (24 bit) | ||
| Timers (64-bit) typ | 4 | |||
| A/D Converters Number of A/D Converters typ | 10 | 10 (10 Bit) | 12 | 8 |
| D/A Converters (12-bit) typ | 2 | |||
| I/Os (High Current) | 30 | 8 | 20 | 31 |
| Display controller | Segment Controller | |||
| CAN typ | 1 | |||
| CAN FD typ | ||||
| I2C typ | 1 | 1 | 2 | 1 |
| SPI typ | 1 | 1 | 4 | 2 |
| I2S typ | 2 | |||
| USB Type | USB FS | |||
| USART typ | 1 | 3 | ||
| UART typ | 2 | |||
| Additional Serial Interfaces | SAI | |||
| Parallel Interfaces | QUAD SPI | |||
| Crypto-HASH | AES | AES-128 | AES, Hash, RSA,RNG | 128-bit AES CCM, ECB, AAR |
| TRNG typ | TRUE | |||
| Supply Voltage (V) min | 2 | 1.8 | 3 | 2.3 |
| Supply Voltage (V) max | 3.6 | 3.3 | 3.6 | 3.6 |
| Supply Current (µA) (@ Lowest Power) typ | 0.04 | 0.24 | 1 to 5 | 0.3 to 1.3 |
| Supply Current (µA) (Run Mode (per MHz)) typ | 90 | 23 | ||
| Operating Temperature (°C) min | -10 | -40 | -40 | -10 |
| Operating Temperature (°C) max | 85 | 85 | 85 | 85 |
| Output Power (Max) | 4 | 2.5 | +4 to -20 (4 dB Step) | |
| Rx Current | 4.5 | 2.2 | 95-100 | 4.6 |
| Rx Sensivity | -100 | -94 | -97 | -93 |
| Standby Current (µA) | 0.25 | 1 | 1.5 | |
| Tx Current 9 (mA) (@0 dBm) max | 5.2 | 3.5 | 80 | 7 |
| Output Power (Max) | 1 | 2.5 | 4 | |
| Connectivity | 2.4GHz,802.15.4,BLE 5.0,Thread/ OpenThread, Zigbee 3.0 | h Bluetooth v5.1, ETSI EN 300 328 and EN 300 440 Class 2 (Europe), FCC CFR47 Part 15 (US) and ARIB STD-T66 (Japan) | Compliant with Bluetooth v4.2 BR/EDR and BLE specifications | Bluetooth 5/ANT/2.4 GHz proprietary |
| Price for Single (Mouser Electronics) | 5.38 $ | 1.64 $ | 2.48 $ | 4.95 $ |
| Price for 50000 (Mouser Electronics) | <2.69 $ | < .625v$ | 2 $ | < 3 $ |
References :www.st.com/content/st_com/en.html, www.nordicsemi.com, www.dialog-semiconductor.com, www.espressif.com/en/
