Raspberry Pi 3A+ vs. 3B+ and all those other models

This post is intended for those that are considering starting their journeys with raspberry pis or just want to know a bit more about what raspberry pi boards offer which features. If you are a raspberry pi history buff, or raspberry pi advocate (me too but for different reasons than yours), read on as well. Leave me some comments! Not only are specifications of raspberry pi board explained, but also my take on the question “why you want a raspberry pi”. If you wish to know more about the differences between different raspberry pi boards, read my next post.

The raspberry pi folks have released another version of raspberry pi, this time, the 3A+ version. I grabbed one right away when my local electronics store got these boards in stock. While I was browsing accessories (believe me you can never have enough raspberry pi accessories), trying to find the official white/raspberry 2-color case, I overhead a couple of people talking about raspberry pi. They were just reading off the labels and that was already confusing enough for them, 3B, 3A+, 3B+, zero-W etc. I know from their voices that they were not being sarcastic, just genuinely confused what’s what. They walked away before I could strike a conversation with them. I thought, if you are just starting with raspberry pi, then what are all these designations and more importantly which board should you get?

The second question is simple, beginners should get the best model, the 3B+ model with the fastest processor + most memory + most USB ports etc. The prices only differ as little as $10. The cheaper ones are meant for more specific applications.

What you get for a rapsberry pi 3B+ is the following features for $35 (extra for required accessories I’ll talk about later). Every feature has my comments for beginners:

Raspberry Pi 3B+:

  • Quad-core 1.4GHz processor: This is a fairly decent processor not too different from the processor of a netbook around $200 (Broadcom BCM2837B0, Cortex-A53 (ARMv8) if you want the details)
  • 1GB memory: This is not a huge amount of memory but the Linux OS is not a memory hog that windows is. (LPDDR2 SDRAM to be exact)
  • Most recent version of Wi-Fi and Bluetooth: you can connect to your home Wi-Fi in seconds although Bluetooth connection can be a struggle just because Bluetooth itself is such a struggle to use (2.4GHz and 5GHz IEEE 802.11.b/g/n/ac wireless LAN, Bluetooth 4.2, BLE if you want to know)
  • Ethernet: connect to your router with a CAT-6 cable for network if you don’t want to use Wi-Fi (Gigabit Ethernet over USB 2.0 (maximum throughput 300 Mbps) to be exact)
  • Extended 40-pin GPIO header: for tinkering with electronics, such as blinking an LED or controlling motors to your custom robot (most accessories sold for raspberry pi are compatible with this pin layout)
  • Full-size HDMI: this is nice so no adapters needed, just straight HDMI cable
  • 4 USB 2.0 ports: minimally you need a keyboard-mouse combo dongle, maybe a flash drive and other devices such as a gamepad, or Arduino etc.
  • CSI camera port for connecting a Raspberry Pi camera: this connects to a camera with special interface for future projects. The camera, which is a $25 separate official accessory, comes with no enclosure or mount. You need an enclosure or separate stand to make it useful. It is also a nice thing since you can make your own design where the camera goes on your own enclosure.
  • DSI display port for connecting a Raspberry Pi touchscreen display: this connects to an official display with special interface for future projects. The display is rather expensive at $60 and needs some assembly. Again it comes without a stand, just the display and an exposed driver board. You need to buy a stand or make your own so the pro of flexibility and con of not a complete solution.
  • 4-pole stereo output and composite video port: probably not useful for most people and projects unless you want your old TVs for display.
  • Micro SD port for loading your operating system and storing data: you need a MicroSD card at least 16GB since raspberry pi has no storage, costing you extra $10.
  • 5V/2.5A DC power input: this is just a MicroUSB socket. You need a USB-to-Micro USB cable (aka Android charging cable) and a phone charger. The required power is rather high so you can’t use your old Android phone charger. I have a couple of generic AmazonBasics chargers with 2A current. Make sure you get a short fast charging cable with thick conductors. Those generic Micro-USB cables have very thin wires that drop too much voltage on themselves so what they deliver to your raspberry pi is often insufficient, causing all sorts of problems.
  • Power-over-Ethernet (PoE) support (requires separate PoE HAT): probably not a beginner’s feature. With the official accessory (a HAT), you can deliver both internet and power through a single CAT-6 cable to your raspberry pi, de-cluttering cables by a great degree. The accessory is “expensive” considering it is $20 extra dollars just to get rid off the Micro-USB charging cable. That’s not the end of it. The other side of the CAT-6 cable, the router, needs to support PoE and has PoE injector. The HAT also covers all your 40-pin headers, so no more tinkering with electronics.

So let’s see, you get a netbook-level computer for $35. Add the following accessories that you may already have:

  • $10 for 16GB+ MicroSD card
  • $10 for USB charger
  • $5 for charging cable
  • $20 for the cheapest keyboard and mouse combo
  • $5 cheap HDMI cable
  • $5 cheap case (official version is $9)

This isn’t everything. If you don’t have a monitor, that’s extra $$$. So the minimal equipment cost is $35. A realistic cost is maybe $75. If you want to set up everything from scratch, it’s $100 plus whatever the cost of a monitor. By this time, you should realize that buying a raspberry pi is not going to save you much money from buying a new PC. A PC laptop with the same if not better spec can be bought for less than $200. You can take said laptop anywhere you want and use it for hours between charges. Raspberry pi can’t do any of that! There are kits you can buy and assemble yourself to make a raspberry pi into a clumsy laptop if you wish to dish out $300+.

So apparently a raspberry pi is NOT a cheap PC replacement! You will NOT save money buy purchasing a raspberry pi! Should you still get it? If you’re deciding between a cheap computer for school and rent, you should just go with a cheap computer. If you have $100 extra money you saved up for “new cool tech things”, you should buy a raspberry pi. That’s right! Raspberry pi is a HOBBY! I don’t remember having hobbies when I was poor. That’s OK. Unless you’re really struggling to support a family, you can find money for this one hobby. Raspberry pi is not an expensive hobby. If you are interested in technology, this hobby will pay you back in many ways that exceed your already-moderate and low-risk investment. Delay that “smart phone” upgrade! All of a sudden, you have extra money! Make yourself sandwiches or some real food, use a few coupons at supermarkets, bring fruit and soda to work/school, come early and find free on-street parking.

Anyway, the real “specs” that I would like to say, are not measured in Gigabytes or GigaHertz. They are measured in more qualitative and subtle things:

  • Take a journey in popular computing technology, with millions of stops depending on what your interests are
  • Become a maker and have computers, sensors, motors, the internet do things for you, not just what you can buy from the stores
  • Be part of an extremely creative global maker community with people from all walks of life with all backgrounds that all share the love for computers and innovation

 

One Response to Raspberry Pi 3A+ vs. 3B+ and all those other models

  1. Pingback: Raspberry pi boards comparison | Liudr's Blog

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: