Many new Bluetooth Low Energy (BLE) chipsets have been released since our last review. Our previous discussion on selecting a Bluetooth chipset went over some of the second-generation devices, but today we’re going to go over the latest devices you should be designing with in 2019 and beyond.
We’re going to cover Bluetooth low Energy devices which let you connect your product to a smartphone for sending data, or create a device connection in various configurations. But, it's important to remember these devices and BLE in general are not designed for high quality audio. If you’re looking for having a device with BLE but also with Audio capability, like speakers and headsets, then the chipset and solution there is more complex. The discussion below is our opinion and based on our experience, but it’s borne by countless designs and discussions with customers and vendors.
BLE has evolved over the last few years from Bluetooth 4.0 to Bluetooth 5.0 and Bluetooth 5.1, and these changes have large ramifications on the chipsets you should be using in your products. Although Bluetooth 4.2 chipsets are still the most common today, Bluetooth 5.0 support has rapidly been making its way to new devices.
Before we cover some of the latest Bluetooth LE 5.0 features, let’s go over what you can do with BLE. At its heart, BLE lets you connect devices and send data wireless. You will typically use a BLE chipset to connect a product to a smartphone, tablet or a custom BLE device, and there are many ways to achieve this depending on the use case. Products that are enabled by BLE run the gamut and include device trackers, consumer products, smart appliances, and much more. Even Toilets have been integrated with Bluetooth LE.
BLE isn’t limited to connecting devices to smartphones. Connecting BLE devices to other BLE devices in custom products is another common use case. The advantage of using Bluetooth is that it lets you focus on your product’s functionality instead of reinventing the wheel and designing wireless protocols from the ground up. BLE is a proven technology that has been deployed by billions of devices. Bluetooth LE covers many of the use cases that use to be relegated to 915MHz/868MHz radios, but with a worldwide 2.4GHz band, frequency hopping against interference, and standardized approach for quick development.
Bluetooth Low Energy tended to work best for applications where data transfer is periodic, but with Bluetooth 4.2 and Bluetooth 5.0, fast transfers for firmware updates, log downloads and communications are better than ever, speeding the process and improving the user experience. The new 2Mbps data rate helps speed things up and enable new features.
Bluetooth 5.0 was released some time ago and includes many improvements to make Bluetooth LE better, among them:
All of these changes allow BLE to transfer more data more efficiently and work better, to meet the needs of product developers building BLE products. They also make BLE a much better IoT connectivity standard. One important thing to note about the longer range and higher speed features is that these are mutually exclusive: you can choose faster data rate or longer range, but not both. Extra output power is helpful in both but consumes more current.
Many of the older Bluetooth LE chipsets and Bluetooth Dual Mode (BLE + Classic) chipsets support only Bluetooth 4.2. Support for 5.0 requires changes in the chipset at the hardware level and is much more expensive for vendors to implement. Some vendors won’t be able to add support for Bluetooth 5 without significant effort.
The good news is that vendors have been working hard to add Bluetooth 5 to their devices and there are many options out there. Some of the devices we will cover will not have Bluetooth 5 support, but that doesn’t make them any less suitable for your product.
Since Bluetooth 5 support is still in progress, there is limited value since not every device can support it. Both devices in the BLE connection have to support Bluetooth 5 to be used, otherwise the connection will fall back to Bluetooth 4.2 or earlier (lowest common denominator). In 2019, we highly recommend having Bluetooth 5 options, even if software support will be added later by the vendors or stack. Chipsets that support Bluetooth 4.2 are slowly going to disappear and receive less and less support. But, some considerations like cost and specific features could lead you to use a Bluetooth v4.2 chipset or older. The benefits of Bluetooth 5 outweigh the effort in many cases, but you may want to analyze it if you have special use case.
The Bluetooth 5.1 specification is the latest Bluetooth released in 2019 and includes changes to enable location via Angle of Arrival (AoA) and Angle of Departure (AoD) mechanisms which can be used for indoor location and positioning applications. Support for these features are enabled in the latest devices (or some specific variants).
If your application requires tracking and locating devices, then it may be critical to use Bluetooth 5.1 chipsets. Leveraging Bluetooth 5.1 requires significant design and testing to ensure reliable operation. We’ll cover it in another discussion and leave it aside in this discussion since it's very specific.
With so many options, we will go over the top vendors available, usually by market share. It’s hard to give an exact figure as far as market share since that information is usually not public, but having worked with almost all of them we have an idea of the vendors commonly used. We are also going to cover chipsets that people can usually use in products, that you can actually develop with and that we've used or evaluated
There are other vendors out there for BLE chipsets. Many of these focus on very low cost, other target some specific application. From our experience these devices come with a cost. Some have low RF performance. Others don't have good software support. Some of the major point to keep in mind:
Nordic has been a top BLE chipset vendor for many years, and at Argenox we’ve been working with Nordic's devices for about 7 years and have created many products based on the nRF8001, nRF51822, nRF52832, nRF52840 chipsets. In recent years Nordic has introduced several devices to its lineup.
Nordic’s devices some of the most commonly used chips in consumer and industrial products, due to a combination of ease of use, great SDK support.
One great thing in Nordic’s chips is that the number of device variants are limited to 2 or 4 per device and the circuit simplicity, which makes it simple to work with. Their devices have broad software support in multiple compilers (GCC, IAR, KEIL) as well as significant software to program and test. Nordic's devices also have significant features, owing to the long history, including the ability to have a large number of simultaneous connections. This expertise in addition to low power, ease of use and a large ecosystem has allowed Nordic to be one of the most popular devices.
Two specific features of Nordic devices are the software defined pin mapping, which allows most pins to be remappable to a specific function in software, as well as the PPI, GPIOTE and other peripherals that make low latency logic easy. In fact, we've used this successfully for applications such as Ultrasonic sensing
These devices are good general BLE devices and fit many applications. However, they do have some limitations that you should consider:
This last point is Nordic's SoftDevice, which is an application independent stack that is placed in the device flash. Although this could be an issue in most cases, the SoftDevice implementation has been well done and overall the number of issues are limited. Compared to other vendors that have a seperate processor, it makes little difference.
Although we covered the nRF52832 chipset before, we cover it again because it is still extremely popular and should be considered one of the top chipsets to use in products. We've used it to build products from smart phone accessories to industrial sensors. It is likely the most popular BLE SoC in the world, if not one of the top 3.
The nRF52832 supports Bluetooth 5 High Data Rate (2Mbps) functionality, but doesn’t have the Coded PHY for long range, which isn't a deal breaker except for specific applications. With up to 512kB of Flash and up to 32kB of RAM, it can address almost any device except the most complex mesh or multi-protocol devices. This device supports only Bluetooth 5.0 and doesn't have any Zigbee or Thread support.
The nRF52840 is the highest end nRF52 chipset that builds on top of the nRF52832. It includes all optional Bluetooth 5 features including:
In addition, what differentiates the nRF52840 from previous devices are a few other features:
The nRF52840 is a great chip for higher end products where the additional memory, USB, higher output power and peripherals are required. It is the most expensive Nordic BLE option. The additional memory is very helpful when implementing multi-radio systems such as BLE + Zigbee or BLE + Thread devices. Bluetooth mesh and mesh solutions can also take advantage of the added memory for large networks.
The nRF52810 is the low end nRF52 part, but only in the sense that features were removed to allow for a cost reduction. It is similar to an nRF52832 with some peripherals and Flash/RAM removed.
This part is ideal for Beacons, communication processors (connecting an existing processor via BLE) or simpler products that don’t require the peripherals, GPIOs or RF performance of the larger nRF52832 devices.
More Info: Nordic Semiconductor nRF52810
The nRF52811 is an SoC designed for Bluetooth 5.1 direction finding applications and is based on the nRF52810 variant. It is an enhanced version of the nRF52810.
More Info: Nordic Semiconductor nRF52811
|Device||2Mbps PHY||Long Range Coded PHY||Advertising Extensions||Channel Selection Algorithm (CSA) #2|
Silicon labs is another popular company that creates a wide range of BLE devices and modules as well as chipsets that include both BLE and Sub-1GHz capabilities. This allows you to bridge between custom designed wireless protocols to smartphones with a single chip.
One advantage of Silabs BLE chipsets are the dual band devices, capable of BLE and Sub-1GHz bands using time-slotting mechanism. This means you will not need to use multiple radios if your product needs to support 915MHz or similar bands while using BLE for provisioning or as a second backhaul.
Silabs also leverages BGScript functionality, where you can create a fully functioning device using a simplified scripting language instead of embedded C code. This works great for many simple devices such as BLE buttons and sensors that don’t need a lot of complexity or processing. Using it can speed up development, but may be limited when processing is needed.
Silicon labs has a multitude of devices. This is both a blessing and a curse, as the slight variations can cause significant confusion. But this can also be a boon to the product developer looking to find the right combination of features and cost.
One other differentiator for Silabs is that they create their own BLE modules, as opposed to using 3rd parties.
BLE RX is 9.5mA compared to other devices at 3.3mA / 5.5mA BLE TX @ 0dBm is 8.5mA compared to other devices at 3.3mA / 5.5mA So Silabs devices are comparable but not the best in their power consumption. Part of this is the result of the high output power the devices can achieve which can impact efficiency.
More Info: Silicon Labs BlueGecko
Recently Silabs announced the BlueGecko Series 2 line of devices designated EFR32BG21, which include even more features
The higher performance and higher BLE radio power consumption target these devices towards higher end products where power consumption is not the top requirement, but where processing capability is.
More Info: Silicon Labs BlueGecko 2
The Mighty Gecko line of devices is one of the highest-end set of devices offered by Silicon Labs and offers a slew of capabilities including support for BLE, Zigbee, Thread as well as Dual-Band. These devices also include large amounts of Flash, RAM and GPIOs to support the high end system in which they can be used. One downside of this is that these also represent the highest cost devices.
More Info: Silicon Labs Mighty Gecko
TI has been in the BLE business since its inception, and the TI CC2540/CC2541 still gets used for many products. In recent years TI has release the CC2640 and variants, including the CC2642R2F which increases the amount of flash and RAM available.
TI’s CC26xx lineup include a unique feature – the sensor controller is an extremely low power CPU that can run simple operations with sensors while the main processor is asleep.
TI’s chipsets have great radio performance which allow long range. Some of the customers publicly known to use CC2640 include Tesla in its car FoBs, but there are many devices.
TI Originally had the CC2640 and CC2650 series of devices. These devices have been augmented by a new generation of devices offering more features, including devices such as the CC1350, which like Silicon Labs EFR32 enable both Sub-1GHz and 2.4GHz BLE in the same system.
TI devices run TI-RTOS and TI’s custom BLE stack. Development is usually done using one of two programming environments:
CCS is an IDE that was quite buggy in the past but has improved greatly with CCS 8. IAR tends to be a good option as it is mostly stable and reliable. CCS does have more visibility into TI-RTOS via plugins, giving it an edge for CC26xx development unless you have an IAR license. TI’s devices have lower flash and memory compared to other vendors, which sometimes results in issues if the device requires a lot of software functionality. We’ve had this happen a few times where even with full optimization, we had to trim functionality to get everything to run.
We recommend going with CC2640R2F at a minimum, avoiding the original CC2640 for new designs. For Bluetooth 5.1 designs or where you need more flash, CC2642R devices provide even more flash space (TI has stated Bluetooth 5.1 support is coming to CC2642R but not CC2640RF2F devices or older).
RB variants (CC2652RB) are a new kind of device that integrates the crystal internally, saving space and potentially cost. This device is at the time of this writing still in preview.
|Device||Bluetooth Support||BLE RF Performance (Sensitivity / Output Power)||Processor||Flash/RAM||Notes|
|CC2640R2F||Bluetooth® 5.0||-97dBm/+20dBm||Cortex-M3||128KB / 28kB||BLE|
|CC2642R||Bluetooth® 5.0||-97dBm/+5dBm||Cortex-M3||352KB / 80kB||BLE|
|CC1350||Bluetooth® 5.0||-97dBm/+9dBm||Cortex-M3||128KB / 28kB||Dual Band - BLE + Sub-1GHz|
|CC1352R||Bluetooth® 5.0||-97dBm/+5dBm||Cortex-M4F||256KB / 16kB||Dual Band - BLE + Sub-1GHz|
|CC1352P||Bluetooth® 5.0||-97dBm/+20dBm||Cortex-M4F||256KB / 16kB||Dual Band - BLE + Sub-1GHz with Power Amplifier|
Cypress (recently acquired by Infineon) has had presence in BLE market for a few years and released the PSOC 6 BLE lineup. PSOC and PSOC 6 devices differentiate themselves with the programmable fabric inside that allows custom hardware implementations which can reduce external logic and cost. For example, custom peripherals can be used together to avoid extra hardware.
Aside from the PSOC 6 BLE devices, Cypress also acquired Broadcom’s IoT unit under which they now sell Bluetooth Classic and Dual Mode transceivers.
As with the previous generation of PSoC 4 and PRoC4, PSOC 6 BLE devices have extensive custom logic capabilities that are unique to Cypress and can be used in a wide array of application to build specific devices. If you're using a PSoC device, then PSoC 6 BLE may be a natural extension to your system. If you require significant analog or processing capabilities, then PSoC 6 BLE may be attractive option.
These devices also include a dual core architecture, with the device containing both a Cortex-M4 processor and a Cortex-M0+ (used for BLE). One of the things that distinguishes the PSoC 6 is the very low active current power
Cypress offers the PSoC Creator development environment which allows for both source code compilation as well as an interface to configure the programmable blocks inherent to these devices.
Cypress is another company that develops custom modules for integrating their BLE devices into designs instead of relying on 3rd party module vendors.
Dialog’s devices have some unique capabilities. In particular, their devices are low power, can run from different batteries and are integrated with many features in a small package. These features make them suitable for smartwatches and similar products, which is where they’ve been used. One popular product using DA14580 (an older Dialog device) is the Tile Bluetooth tracker. Some of the unique features of Dialog devices are:
One downside for a long time has been that Dialog's RF performance has lagged behind others. Sensitivity would be around -93dBm to -94dBm, while output power was limited to 0dBm. However, the latest generations are moving towards an improved RF that would provide a better BLE link.
The DA14680 and DA14681 are an upgrade for the DA14580, the low power chipset that has been used in many devices and the one that powers the Tile Bluetooth tracker.
The DA14680 and DA14681 are a new series of devices that include USB 1.1 support but support up to Bluetooth v4.2.
This is Dialog’s latest chipset, which is a much higher end device that is targeted towards more capable smart watches and similar higher end consumer products. However, there can be many products that can take advantage of the features and capabilities of this device.
This device and Dialog’s other devices are typically ideal for Rechargeable Lithium Ion/Poly batteries applications (did we mention smartwatches?) where the M33 high power consumption can run.
Qualcomm is the largest wireless connectivity company, and a few years ago they acquired CSR, a British company that pioneered much of the Bluetooth audio chipsets that dominate speakers, headsets and other devices.
CSR also developed BLE only chipsets, with mixed results. These devices, CSR102x (including the previous generation CSR101x) are very low power and usually low cost, but have some drawbacks:
Although these devices are designed for broad market, the reality is that Qualcomm targets primarily high volume manufacturers. Information regarding their devices, software is often closely guarded, which requires a direct engagement with Qualcomm. CSR1xxx devices are better, but still more difficult to use compared to other vendors.
The reality is that it doesn’t seem Qualcomm has been investing much into the development of new BLE only devices. That’s not surprising given that it’s a highly competitive place and Qualcomm does much better with their Dual Mode (Classic + BLE) devices. The devices are much more targeted towards verticals such as remote controls, where there are high volume design wins instead of more general IoT products.
Despite this, these devices do have some interesting features:
|CSR1020||Bluetooth® 5.0||16-bit 16MHz RISC||256KB / 16kB||One-Time Programmable|
|CSR1021||Bluetooth® 5.0||16-bit 16MHz RISC||256KB / 16kB||One-Time Programmable|
|CSR1024||Bluetooth® 5.0||16-bit 16MHz RISC||256KB / 16kB||Flash|
|CSR1025||Bluetooth® 5.0||16-bit 16MHz RISC||256KB / 16kB||Flash|
Through its acquisition of Freescale a few years ago, NXP added the Kinetis BLE line of BLE SoCs in addition to its own line of devices.
These devices represent the latest offering from NXP, an upgrade from their KW41 series which came from Freescale. One of the unique features of the KW36 is the addition of a CAN bus, since these devices are targeted mostly at automotive applications. the KWxx series are also automotive qualified.
These devices represent the latest offering from NXP originally from the NXP side of the acquisition. The RF performance is decent but they distinguish themselves with very low power consumption.
ST is a leader in Cortex-M processors and their line of processors is used in countless products. They've also expanded into BLE with the BlueNRG line of devices whose performance was not as competitive as other devices. However, ST has recently launched the STM32WB55xx line of advanced BLE devices that are based on the STM32L4 and that rival the best of BLE chipsets.
STM32WB55xx blends many of the features ST is famous in its line of microcontrollers to create an industrial high-end device with a slew of features:
The STM32WB55xx devices do not support LE Long Range, which could be a requirement for some industrial or commercial applications.
|Device||Protocols||BLE RF Performance||Processor||Flash/RAM||Current Consumption BLE @ 0dBm|
|Nordic nRF52810||Bluetooth® 5.0||-96dBm / +4dBm||Cortex-M4||192KB / 24kB||4.6mA / 4.6mA|
|Nordic nRF52811||Bluetooth® 5.1, 802.15.4, Thread, Zigbee||-96dBm / +4dBm||Cortex-M4||192KB / 24kB||4.6mA / 4.6mA|
|Nordic nRF52832||Bluetooth® 5.0||-96dBm / +4dBm||Cortex-M4||192KB / 24kB||4.6mA / 4.6mA|
|Nordic nRF52840||Bluetooth® 5.0, 802.15.4, Thread, Zigbee||-95dBm / +8dBm||Cortex-M4||1MB / 64kB||4.6mA / 4.6mA|
|TI CC2640R2F||Bluetooth® 5.0||-97dBm/+20dBm||Cortex-M3||128KB / 28kB||5.1mA / 6.1mA|
|TI CC2642R||Bluetooth® 5.0||-97dBm/+5dBm||Cortex-M3||352KB / 80kB||5.1mA / 6.1mA|
|TI CC1350||Bluetooth® 5.0||-97dBm/+9dBm||Cortex-M3||128KB / 28kB||5.1mA / 6.1mA|
|TI CC1352R||Bluetooth® 5.0||-97dBm/+5dBm||Cortex-M4F||256KB / 16kB||5.1mA / 6.1mA|
|TI CC1352P||Bluetooth® 5.0||-97dBm/+20dBm||Cortex-M4F||256KB / 16kB||5.1mA / 6.1mA|
|Qualcomm CSR102x||Bluetooth® 5.0||-92dBm / +4dBm||16MHz 16-bit RISC||64kB / 16kB||< 5mA|
|Dialog DA1469x||Bluetooth® 5.1||-92dBm / +4dBm||Cortex-M33||32 Mbit (ext.) / 512kB||< 3.5mA|
|ST STM32WB55||Bluetooth® 5.0, Zigbee, Thread||-96dBm / +6dBm||Cortex-M4F||1MB / 256kB||4.5mA/5.2mA|
|Silabs EFR32BG21||Bluetooth® 5.0, Zigbee, Thread||-97dBm / +20dBm||Cortex-M33||1MB / 96kB||8.8mA/9.3mA|
|NXP KW36||Bluetooth® 5.0||-95dBm / +3.5dBm||Cortex-M0+||512kB / 64kB||6.1mA / 6.8mA|
|NXP QN908x||Bluetooth® 5.0||-95dBm / +2dBm||Cortex-M4F||512kB / 64kB||3.4mA / 3.4mA|
Every product is unique, so finding the right device could be easy or difficult depending on the specific product requirements.
If you’re comparing devices, make sure to look at the fine print regarding RAM and Flash/ROM. In some cases, RAM is being used for the BLE stack or for other purposes and you will have less space than you thought for your application. In TI devices, some RAM is actually shared.
We covered primarily the current consumption of the radio, using it as a proxy for overall power measurement. The reality as you can imagine is much more complicated. Depending on your application, active current or sleep current will dominate. Also, the CPU activity will matter, and some of the CPUs are more sophisticated than others, capable of processing data faster. Therefore, this could require significant analysis of the actual application to optimize. In reality, optimizing solely for power consumption can't be done except where the BLE application is highly focused. Other factors matter: cost, software support, etc.
We’ve covered some of the most popular BLE and Bluetooth devices, their specifications and some of the key aspects to keep in mind when making a decision.
As always, there are many details and concerns that come into play when creating a BLE product. We’re committed to help you get it done right, so feel free to get in touch with us to discuss.
Photos courtesy of Nordic Semiconductor, Texas Instruments, Cypress Semiconductor, Qualcomm, Dialog Semiconductor and Silicon Labs.