First released in 2012, the first Raspberry Pi featured a 700 MHz single core processor and 256 MB of RAM. The Raspberry Pi 2 was released in February of 2015 with a 900 MHz quad core processor and 1 GB of RAM. Released in February of 2016, the Raspberry Pi 3 increased the processor speed to 1.2 GHz. This model was also the first one to include wireless LAN and Bluetooth.
Here is an image of a Raspberry Pi 3 B (2015):
This version of the Raspberry Pi features the following parts:
- Four USB 2 ports
- A LAN port
- A 3.5 mm composite video and audio jack
- An HDMI port for video and audio
- An OTG USB port (which we will use to connect the power)
- A microSD slot (to hold our operating system)
- A DSI display port for the Raspberry Pi touchscreen
- A General Purpose Input Output (GPIO) pins
- A camera port for a special Raspberry Pi camera
The Raspberry Pi Zero was released in November of 2015. Here is an image of it:
Although not as powerful as the previous Raspberry Pis, the Zero featured a smaller size (65 mm X 30 mm), perfect for projects with limited physical space (namely, wearable projects). Plus, the Raspberry Pi zero was priced at $5 USD, making it very affordable. The Raspberry Pi zero W was released on February 28, 2017 at double the price ($10 USD) with built-in Wi-Fi and Bluetooth capabilities.
The latest model, as of the time of writing, is the Raspberry Pi 3 B+, which was released on March 14, 2018. The processor speed has been upgraded to 1.4 GHz as well as the wireless LAN now supporting both 2.4 GHz and 5 GHz bands. Another upgrade is the addition of Bluetooth low energy, a technology built for applications that do not require large amounts of data to be exchanged but are required to have a long battery life.
Creators of the Raspberry Pi initially believed that they would sell at most 1,000 units. Little did they know that their invention would explode in popularity. As of March 2018, sales of Raspberry Pi computers has passed the 19 million mark.