Bluetooth classic and low energy

ESP32 – Bluetooth Classic vs Bluetooth Low Energy (BLE)

ESP32 is a microcontroller based electronic platform that comes with wireless capability by providing users with WiFi and dual Bluetooth. ESP32 can turn any project into a wireless based device using WiFi and Bluetooth. Let’s discuss the use of Bluetooth technology inside ESP32.

What Is Bluetooth in ESP32

Bluetooth is a radio technology that transmits data within 2.4GHz bands. To transmit these data packets there are 79 designated channels each of 1 MHz in bandwidth. Bluetooth in ESP32 allows connecting multiple devices such as mobile phones, PCs, sensors, and many more.

Types of Bluetooth in ESP32

When it comes to types of Bluetooth, we should keep in mind the power consumption of Bluetooth because that’s the main reason behind division in Bluetooth technology. ESP32 is a low power IoT based microcontroller board where we have to keep the power as low as we can.

With the launch of Bluetooth technology till now there are multiple improvements and re-creation inside this technology. Depending upon the power consumption of Bluetooth we can divide it into two types:

Bluetooth Classic in ESP32

Bluetooth Classic is the basic or first variant of Bluetooth technology that has been here for the last 20 years. It is a wireless LAN technology that operates in 2.4Ghz bands and Bluetooth classic can be divided into two types based upon the data rate:

• Basic Rate (BR): It is the standard radio modulation having 1MB/s data transfer rate. It is used for transmitting audio and sometimes video.
• Enhanced Data Rate (EDR): It was introduced to increase data transfer rate from 1MB/s to 3MB/s that allows it to operate high end CODECs.

Both Bluetooth Classic and BLE operate in the 2400-2483.5 MHz range within the ISM 2.4 GHz frequency band. However Classic Bluetooth communication happens over any one of 79 channels on the other hand BLE has only 40 designated channels.

The high data transfer rate of Bluetooth classic helps it to carry high quality audio which is not possible in BLE. Supporting point-to-point communication, Bluetooth classic has become standard for audio streaming, headphone, and in-car entertainment systems.

Following are some major applications of Bluetooth Classic:

• Transferring files between devices
• Hands-free calling
• Wireless speakers
• Wireless headsets
• Wireless keyboards and printers

Bluetooth Low Energy (BLE) in ESP32

BLE (Bluetooth Low Energy) or Bluetooth 4.0 is the upgraded version of basic Bluetooth technology that came into market in 2011. From the name BLE we can conclude that it is a low-energy version of Bluetooth technology. BLE consumes very less power and is a perfect fit for boards like ESP32.

Unlike Bluetooth Classic it doesn’t remain on all the time rather it goes to sleep mode and only enables when connection is initiated, this helps pretty much in saving a large amount of power. With its low energy capability ESP32 can exchange small amounts of data from sensors without any need of extra power. As it can run for a long time consuming very low power.

Here is a list of BLE applications:

• Blood pressure monitoring
• Fitness devices
• Monitoring sensors
• Geofencing advertising
• Home security sensors
• IoT based applications

Brief Comparison of Bluetooth Classic and Bluetooth Low Energy

Key difference here is Bluetooth consumes a large amount of power and transfers high quality data while Bluetooth Low Energy does not need to exchange large data and can run on batteries for years. Let’s discuss the comparison based on various parameters.

Power Consumption

Bluetooth low energy has the main feature of low power consumption as it enables devices to run for more than a year by just using a single coin cell battery. This happens because BLE devices remain in sleep mode throughout, it only wakes up when data needs to be transmitted. Maximum current consumption is only 15mA.

BLE – Winner

Range of the Device

When it comes to range of Bluetooth the winner is Bluetooth Classic as its opponent consumes very less power which enables it to work for a longer period on a single cell, but this feature reduces the range of Bluetooth devices. So, if one needs a longer range, he has to consider Bluetooth classic.

Classic Bluetooth – Winner

Throughput

The actual data transfer rate for Bluetooth Low Energy is around 100 – 250 Kbps as compared to Classic Bluetooth which is around roughly 2 Mbps. Therefore, transferring high quality audio video data cannot be transferred using the BLE. Classic Bluetooth is the way to go. However, for low data transfer with less power and latency BLE is the best fit.

Classic Bluetooth – Winner

Cost

BLE devices as compared to devices having Bluetooth Classic are very much cheaper. This is possible because BLE is designed for low power consumption applications and hence has less data transfer rate and speed. On the other hand, Bluetooth Classic has complicated protocols which require large batteries to transfer data and hence are relatively expensive.

BLE – Winner

Number of Slaves Attached to the Master

BLE devices supports a greater number of slaves devices in comparison to other versions. It all depends upon the implementation of BLE and memory size availability inside the devices.

BLE – Winner

Connection Setup Speed

BLE is easy to set up, robust and reliable. As most of us wear classic Bluetooth smart bands. The seamless connectivity between smart band and smartphone is only possible because of BLE. All these smart devices keep connected to other devices for a longer period only because of BLE.

Also, most features of Low Energy Bluetooth are taken from Classic Bluetooth technology such as adaptive frequency. BLE like Classic Bluetooth uses the same technology for not only pairing devices but also features advanced security authentication and data encryption. All these features make BLE more reliable than Classic Bluetooth.

From this comparison we can conclude that BLE beats Classic Bluetooth in most terms. However, at the end it all depends upon the usage and user preference to whether use BLE or Classic Bluetooth.

BLE – Winner

Here we have enlisted a brief comparison of Bluetooth Classic and BLE:

Feature	Bluetooth Classic	Bluetooth Low Energy (BLE)
Data rate	1Mbps for B 2-3Mbps for EDR	Up to 1Mbps
Power Consumption	High (up to 1W)	Low (0.01W-0.5W)
Audio Streaming	Original audio protocol used in most of devices	New LE audio protocol will replace the classic protocol because of low energy requirements and easy to handle
Range	Limited range 10m – 50m	Long range introduced in Bluetooth 5.0 up to 1km in line of sight
RF bandwidth	2.4 GHz ISM band (2400-2483.5 MHz)	2.4 GHz ISM band (2400-2483.5 MHz)
Number of channels	79 RF channel each of 1MHz	40 RF channel each of 2MHz
Modulation Technique	GFSK for Basic data rat 8-DPSK or π/4-DQPSK for Enhanced data rate	GFSK
Topology	Peer to peer (1:1)	Peer to peer (1:1) Star topology (many:1) Broadcast (1:many) Mesh (many:many)

Conclusion

ESP32 has dual Bluetooth technology having both Classic and Low Energy version of Bluetooth. Bluetooth Classic is a basic variant of Bluetooth that consumes more power while Bluetooth Low Energy targets the low power applications such as exchanging data from sensors at regular intervals. This article covers the brief comparison of both ESP32 Bluetooth technologies.

About the author

Kashif

I am an Electrical Engineer. I love to write about electronics. I am passionate about writing and sharing new ideas related to emerging technologies in the field of electronics.

Источник

The Difference Between Classic Bluetooth and Bluetooth Low Energy

The naming conventions for Bluetooth technologies have changed over the years and still cause confusion to this day. Here is everything you need to know.

Understanding the differences between classic Bluetooth and Bluetooth Low Energy is a critical first step for any Bluetooth development project. Why do two partly incompatible protocols share a name? What happened to Bluetooth Smart? Which protocol is best for your application? These are common questions from people new to the world of Bluetooth.

To fully understand the situation today, we must first understand how we got here.

The history of Bluetooth releases

When we talk of Bluetooth before 2010, we refer to classic Bluetooth as the Low Energy variant didn’t yet exist. Classic Bluetooth is proposed and maintained by the Bluetooth Special Interest Group (SIG).

Each time Bluetooth SIG releases a new version of the specification, it states a version number. Bluetooth 1.0 was released around 1999, version 2.0 in 2004, version 2.1 in 2007, and version 3.0 in 2009. If you open the Bluetooth 3.0 specifications, you will find that classic Bluetooth includes three modes: BR, EDR, and HS (AMP).

The introduction of Low Energy

In short, any technology released by SIG can be called Bluetooth technology. In 2010, Bluetooth SIG merged with Wibree. The wireless technology was founded by Nokia, Nordic Semiconductor, and other parties, to find a lower-power wireless communication technology for mobile phone peripherals.

The Bluetooth SIG renamed the low-power wireless technology ‘Bluetooth Low Energy’ (Bluetooth LE). In 2010, the Bluetooth 4.0 specification included both classic Bluetooth and Bluetooth LE.

Actually, the term ‘classic Bluetooth’ isn’t completely accurate. In the Bluetooth 4.0 specification, the SIG defined the four Bluetooth controller technologies: BR, EDR, AMP, and LE.

That means there is only one Bluetooth, which is the SIG’s Bluetooth. The Bluetooth technology itself includes four types: BR, EDR, AMP, and LE. Since LE was proposed in 2010 and is relatively new, people call the former BR/EDR/AMP technology ‘classic Bluetooth’ technology for convenience.

Don’t make the mistake of thinking that Bluetooth only has the LE mode after Bluetooth 4.0!

Not so smart

Initially, the SIG promoted Bluetooth LE as ‘Bluetooth Smart’ to distinguish it from the classic version, which used the standalone term ‘Bluetooth.’ Also, ‘Bluetooth Smart ready’ was used to represent the dual-mode Bluetooth that would support both variants.

Instead of spreading the brand and bringing clarity, the naming confused both consumers and developers. SIG then decided to stop using these names and bring everything under the Bluetooth 4.0 umbrella.

That’s why there is considerable publicity material out in the market featuring the now-defunct names Bluetooth Smart and Bluetooth Smart ready.

Different Bluetooth for different applications

The Bluetooth 4.1 – 5.2 released by SIG includes both Bluetooth Low Energy and classic Bluetooth. So when developing Bluetooth applications, you must be clear which version to use as they work differently.

Generally speaking, classic Bluetooth is currently mainly used for audio, such as wireless telephone connections, wireless headphones, and wireless speakers, a lthough this might change in the following years with Bluetooth LE Audio.

Bluetooth Low Energy is more often seen in wearable devices, smart IoT devices, fitness monitoring equipment, and battery-powered accessories such as a keyboard. Of course, classic Bluetooth can also be powered by batteries, but LE’s power requirements are lower. In some cases, LE devices can even be powered by button batteries.

This table summarises typical applications (click on pic for larger version):

It’s important to note that each mode has different physical layer modulation and demodulation methods. This means that Bluetooth LE and classic Bluetooth devices cannot communicate with each other. If the master device is a Bluetooth LE device, the slave device must also be a Bluetooth LE device.

Smartphones can work with both

That said, there is a dual-mode Bluetooth device in the market, which supports both Bluetooth LE and classic Bluetooth. Cell phones are the most common example. Most modern smartphones can communicate with both classic and LE devices.

To achieve this, smartphones use a time-sharing mechanism to communicate using both Bluetooth modes. Smartphones allow dual-mode Bluetooth chips to continuously switch between modes to support both Bluetooth LE devices and classic Bluetooth devices.

Whether it’s Bluetooth LE, classic Bluetooth, or dual-mode Bluetooth solutions, fully understanding and appreciating the differences between them is an important step in choosing the most suitable solution for your IoT project.

This is an updated version of an article published in April 2019.

Источник