Like its predecessors, the Raspberry Pi 3 (RP3, or Raspberry PI 3 Model B) is a $35 computer the size of a credit card that can be plugged into a monitor or television and hooked up to a standard keyboard and mouse.  The RP3, again like its predecessors, can interact outside of itself via easy to use sensors that communicate with it through its GPIO (General Purpose Input/Output) interface.

For those of you already familiar with the RP, be aware that RP3 board is going to look very similar to that of its predecessors, but don’t be deceived!  The RP3 is significantly faster, more powerful, and offers better energy management than any of the other RPs.  It also has built-in Wi-Fi and Bluetooth connectivity, making it ready to engage with the Internet of Things out of the box.

In this chapter, we are going to discuss how the RP3 is different from its predecessors followed by how it is the same.  Then we will look at the specifications for the RP3 in more technical detail.

How the RP3 is Different

First, it offers wireless LAN capabilities, which none of its predecessors did.  In addition, the wireless LAN and Bluetooth are provided by a tiny Broadcom BCM43438 chip that has been built in the board.  One of the bonuses of this chip is that the Bluetooth 4.1 Classic provides radio support.  In the previous models, you had to add USB dongles to accomplish this, which was not only inconvenient but a drain on available power.

In addition, it does not need any type of external antenna.  To keep the device size as small as possible, the chip antenna was soldered directly to the board and does an excellent job of picking up both Bluetooth and LAN signals through walls.  Doing this required that the LEDs be moved to another location on the board, which may be one of the differences that is easy to spot.

The Broadcom BCM2837 SoC was specifically built for the RP3.  It has four ARM Cortex-A53 processing cores that run at 1.2 GHz.  Their cache memory is 32kB Level 1 and 512kB Level 2, and they are 64-bit instead of 32-bit like the RP3’s predecessors.  It also includes a VideoCore IV graphics processor, giving it graphics capabilities on the same order as the first XBox.  It links to 1 GB RAM memory located on the rear of the board.  Because of this, the RP3 significantly outperforms all its predecessors when running either single threaded or multithreaded.

How the RP3 is the same

Likes the RP2, the RP3 offers 1 GB of RAM, 4 USB ports, an Ethernet port, an HDMI port, 40 GPIO pins, and a VideoCore IV 3D graphics core.  It has a combined 3.5 mm audio jack and composite video.  It includes both a camera interface and display interface, and a microSD card slot (except now it is push-pull instead of push-push).  It’s form factor is the same as the RP2 and RP1 B+ and is fully compatible with the RP1 and RP2.

It also supports the same languages:  anything that can be compiled to run on its ARM CPU, such as C, C++, Ruby, Java, Scratch, Sonic Pi, and the RP Mathematica.

Specifications

Let’s take a look at some of the more technical specifications.  The SoC (system-on-chip) is a Broadcom BCM2837.  Its CPU consists of Broadcom BCM2837 a 64 bit ARMv8 Cortex-A53 64-bit processor running at 1.2GHz with 1 GB LPDDR2 900 MHz RAM and a VideoCore IV 3D GPU.  One the key features that differentiates it from its predecessors is that it has a 2.4GHz 802.11n wireless built-in along with 10/100 Ethernet.  It includes both Bluetooth Low Energy and Bluetooth 4.1 Classic. 

It features microSD storage, and the following ports:  HDMI, 3.5 mm analog AV jack (stereo audio and composite video), (4) USB 2.0, CSI serial interface (for connecting a non-USB camera), DSI display serial interface (for connecting a touch screen display), and Ethernet.  The GPIO pin arrangment harks back to the RP Model B+ and Model A+ with a 40 pin extended general purpose IO header.  Like the RP2, it has an SMSC LAN9514 chip.  It offers both HDMI and RCA output.

The maximum microSD card size the RP3 can support it 32 GB.  The minimum required microSD card size is 6 GB, but 8 GB is better you have to go with a more inexpensive microSD card.  If you need additional storage, you can use a USB drive or USB hard drive.  Keep in mind that the SD card is where the operating system will be stored.

It draws 2.5V @ 5V, which is a  bit higher than the RP2 model which used 1.8V @ 5V.  This, combined with the fact that the WiFi is not built in, allows you to power even more devices through the USB ports without always needed a powered USB hub. In fact, this is a significant upgrade to the switched power source.

Conclusion

Many people love the RP2 because it is an inexpensive way to learn about how computers work and how to program.  Some people love it because it lets them take their knowledge of coding outside of a computer and into areas like mechatronics and the Internet of Things.   Finally, some people who have struggled with learning to program might just find the confusion begin to clear up when, instead of seeing numbers on a screen, they see LEDs light up.

Online Resources:

Raspberry Pi Foundation Website: