Bluetooth 4.2

The RPi3B supported Bluetooth 4.1; thanks to the CYW43455, the RPi3B+ now offers Bluetooth 4.2 – that is, "Bluetooth Classic" and Bluetooth LE (Low Energy). Version 4.2 improves speed, privacy, and data security for Bluetooth LE. Compared with the previous version, the data packets are two and a half times faster and are capable of containing up to 10 times more data.

Bluetooth 4.1 already provides for easier connection of devices without a hub, but Bluetooth 4.2 takes this to a whole new level: The IPSP-supported 6LoWPAN (Internet Protocol Support Profile/IPv6 over low-power wireless personal area networks) takes IPv6 to small, low-performance devices for integration into the Internet of Things.

The Generic Attribute Profile (GATT) provides a smart Bluetooth gateway to the Internet. For example, a BLE 4.2 sensor can send and receive messages through the RPi3B+ as a gateway. Bluetooth beacons that attempt to track your device require explicit permission as of v4.2. The LE Secure Connections pairing option is also available as of Bluetooth 4.2.

Performance

I was only able test the RPi3B+ for this article with a pre-release image with wireless not yet enabled and the CPU still clocked at 1.2GHz. A test with the new software image is coming soon, and the performance values for the RPi3B+ should improve significantly. As Table 1 shows, though, they are already impressive.

Both the RPi3B and RPi3B+ devices were tested with a SanDisk SD card (class 10) and an EM 231 energy monitor by MK Electronics. A keyboard and HDMI and Ethernet cables were connected. The remote station in the LAN was a GigE port on a laptop connected with a gigabit switch by TP Link.

Interesting Facts

To run all functions of the new RPi3B+, you definitely need new software: It does not boot with NOOBS before version 2.7.0 dated March 14, 2018. The developers are also working on a firmware update for Raspbian Jessie. Other distributions, like LibreELEC and RetroPie, will follow suit in time.

The 40-pin GPIO header stayed the same, so all extension HATs fit. As with the RPi3B and Pi Zero W, Bluetooth is connected via the UART (PL011). If you use the UART through the GPIO header, you should note the known limitations of its mini UART. Alternatively, swap the two UARTs via overlay or disable Bluetooth [4].

The RUN header previously had two pins, of which one was ground suitable for mounting a reset button. However, the power supply remained switched on. With the RUN pin continuously grounded, the CPU was off for all intents and purposes, but the hardware still consumed power.

In the RPi3B+, the ground pin was removed from this header and a new PEN (power enable) pin was added. If you connect it to ground, it completely drains the power from the board. The board then transitions to the lowest consumption state possible, making it useful for projects that operate with a battery and wake up using a microcontroller.