So lets talk Pi.
We already gave a quick overview on the available Pi’s and which one you should chose.
But we can doe better then a 5 min read on that. Lets begin with listing all the available Raspberry Pi modules from old to new.
- Raspberry Pi A (2012)
- Raspberry Pi B (2012)
- Raspberry Pi A+ (2014)
- Raspberry Pi B+ (2014)
- Raspberry Pi Compute Module (2014)
- Raspberry Pi 2B (2015)*
- Raspberry Pi Zero (2015)
- Raspberry Pi Zero W (2015)
- Raspberry Pi 3B (2016)
- Raspberry Pi Compute Module 3 (2017)
- Raspberry Pi 3A+ (2018)
- Raspberry Pi 3B+ (2018)
- Raspberry Pi Compute Module 3+ (2019)
- Raspberry Pi 4B (2019)
- Raspberry Pi Compute Module 4 (2020)
- Raspberry Pi 400 (2020)
As of January 2021 there are already 16 different Pi versions on the market.
So how can you pick the best one for your project? Lets find that out.
Note that I do not own every Pi myself. So some are speculations or info received on the official pi website.
Intro To the Pi’s
So what pi does what, what has it on board and where can we use it?
Lets start back in 2012 with the Pi A
It all started with the first generation of boards in 2012 consisting of the model A and model B.
Both show some big similarities but they also have the odd 26 pin GPIO header, this is later replaced by the now used 40 pin header. These headers contain the SPI/I2C/UART/GPIO pins.
They both have a HDMI port, RCA connector, Audio jack 3.5mm, USB port, camera ZIF socket and display ZIF socket (DSI-bus). Unlike the newer variants these use a full sized SD card.
Raspberry Pi A
The A model uses a Broadcom BCM2835 SoC with a memory of 256 MB
Raspberry Pi B
Unlike the model A, the model B uses a BCM with a memory capacity of 512 MB.
Other then that it also uses a USB 2.0 hub to allow for the use of the LAN chip and Ethernet port next to the USB port.
The model B also comes with 2 USB ports instead of one.
The 2nd generation comes with an update for both boards, now named A+ and B+.
The + in there names tell us its not a fully new design but a smaller revision of the board.
But is it a small change?
One thing that stands out is that the board are no longer the same between the 2 versions.
The model A now has his own board, and both are lacking the composite port (RCA connector).
The 26-pin GPIO header has now been replaced with a 40 pin header.
But most likely one of the bigger changes was the use of a micro SD card instead of a full size one.
The 2nd generation of raspberry Pi’s is a little bit bigger then the previous 2 with the introduction of the Pi Zero and the Compute Module.
All of the future modules, except of the compute modules, use the now standard 40 pin GPIO header.
Raspberry Pi Compute Module
The Compute module is no longer a single board computer but intended for integration in customer products using a SODIMM slot.
There are 3 version of this Compute Module available but all are replace by the newest one.
The first compute module has the same CPU as the Gen 2 devices (BCM2835) with 512MB of RAM. In addition this board has an onboard 4GB (eMMC) flash memory that is equivalent to the SD card. Unlike the single board version the compute module has many more GPIOs available.
Raspberry Pi Zero
Like the Model B, B+ and A+ the Pi Zero has 512MB of RAM with a 1GHz processor.
Unlike these models it doesn’t have a full size HDMI port but a Mini HDMI port, a small adapter cable is required to connect it to a monitor if required.
There are 2 versions of the Pi Zero, One with wireless connectivity and one without.
Note that none of them have an Ethernet port. They do however have USB OTG support.
If you require Ethernet you can add a small micro-USB to Ethernet module.
Raspberry Pi 2B
The model B has been over a few iterations and the latest model in the gen 3 is the 3B+.
The 2B version is the first one with 1GB of RAM and this hasn’t changed in this generation.
Raspberry Pi 3B(+)
Both the 3B and 3B+ have on board Wi-Fi, there is no longer a need for a Wi-Fi dongle. And it also includes Bluetooth BLE.
The 3B+ even has 1Gb Ethernet speeds, thought this is still shared with the USB so if you are using lots of USB and Ethernet at the same time it won’t be up to speed.
The RPI 3B+ is the first one who is ‘capable’ of accepting PoE, or Power over Ethernet (see our PoE tutorial), But you will need a HAT for this to work.
Both the 3B and 3B+ come with a 64bit processor, previous boards only had a 32bit processor.
So it is now theoretically possible to run windows on it (but it won’t run smooth yet).
Raspberry Pi 3A+
The A model hasn’t had an update since Gen 1.1, but at last here it is. it has a similar processor as on the 3B+ model with 64bit code but only 512MB of RAM.
There is no CM2 version available. Both the modules are based on the CM1 and the corresponding SBC (Single Board Computer) (resp. the RPI 3B and RPI 3B+)
The CM3+ comes in a 8GB/16GB/32GB eMMC memory variant or a Lite variant without this memory.
In the 4th generation every thing becomes more interesting, thought there are only 3 different models in this generation (of which 2 are updates).
Raspberry Pi 4B
Here is where things began to be interesting, they released versions up to 8GB of RAM, separate gigabit Ethernet (no longer shared with USB) USB3.0 Ports and 2 HDMI ports (but there are micro HDMI).
This makes it possible to have 2 screens attached and actually have a dual screen configuration.
The Pi 4B has 4 versions: 1GB*, 2GB, 4GB and 8GB.
* The 1GB version is no longer available.
But if you wish to use it in an existing project mind following changes.
The Ethernet port has switched sides and is now in the right hand side and no longer on the left. This together with the HDMI change make it impossible to mount it in cases designed for the Pi2-3B+.
And don’t forget it has a USB C port that supports OTG!
Raspberry Pi Compute Module 4
The power of Raspberry Pi 4 in a compact form factor for deeply embedded applications. Raspberry Pi Compute Module 4 incorporates a quad-core ARM Cortex-A72 processor, dual video output, and a wide selection of other interfaces. Available in 32 variants, with a range of RAM and eMMC Flash options, and with or without wireless connectivity.raspberrypi.org
As with previous CM modules its base on the equivalent SBC (resp. the RPI 4B)
But it no longer comes in a SODIMM package and thus not backwards compatible.
It comes in 32 different variant (Say WHAT?), this due to the many options available and to much to sum up.
Raspberry Pi 400
Raspberry Pi 400 is your complete personal computer, built into a compact keyboard. Featuring a quad-core 64-bit processor, 4GB of RAM, wireless networking, dual-display output, and 4K video playback, as well as a 40-pin GPIO header, it’s the most powerful and easy-to-use Raspberry Pi computer yet. Raspberry Pi 400 is also available as part of a complete kit including a mouse, power supply, preloaded SD card, and more.Raspberrypi.org
The novelty about the Pi 400 is that its build into a keyboard.
There is 1 less USB port as it is used by the keyboard but otherwise is a nice looking kit.
It only comes in the 4GB version, but comes with a faster processor.
So as of January 2021 these are all the available Raspberry Pi’s. Some might be no longer in production or already have an EOL date (End Of Life).
In most cases you’ll want a Pi 3B+ or any flavour of Pi 4B, if you wish to run windows you are better of with the Pi 4B 8GB, the 1-2GB versions are not supported in the current port.
If you have any question, pointers or remarks. Head over to our contact page and contact from there.
Otherwise I’ll see you in our next tutorial?