Raspberry Pi 3 Model A+ - Review

Table of contents

RoadTest: Raspberry Pi 3 Model A+

Author: brains93

Creation date:

Evaluation Type: Development Boards & Tools

Did you receive all parts the manufacturer stated would be included in the package?: True

What other parts do you consider comparable to this product?:

What were the biggest problems encountered?: Lack of USB ports on the board.

Detailed Review:

I am reviewing the Raspberry Pi 3 model A+

 

 

Overview

 

So, for anyone who does not know, the Raspberry Pi is a small inexpensive single board computer. It has a few variations;

 

  • Model B & B+
  • Model A + A+
  • Pi Zero

 

The Model B & B+ are the flagship models that most people think of when they think of the Raspberry Pi, these are the "Full featured" boards with all the frills and trimmings whereas the A, A+ and Zero are trimmed down version either for cost or low footprint to fit other applications.

The A+ is the latest model to come out and was intended to be a cheaper version of the B+ but with as much punch, and it certainly does that, the specs and bench tests that have been done comparing the two have all agreed that the A+ kicks no small amount of ass when side by side with the B+

 

 

A+ Spec

  • SoC: Broadcom BCM2837B0 quad-core A54 (ARMv8) 64-bit @ 1.4GHz
  • GPU: Broadcom VideoCore IV
  • Networking: 2.4GHz and 5GHz 802.11b/g/n/ac wireless LAN
  • RAM: 512MB LPDDR2 SDRAM
  • Bluetooth: Bluetooth 4.2, Bluetooth Low Energy (BLE)
  • GPIO: 40-pin GPIO
  • Storage: microSD
  • Ports: HDMI, 3.5 mm analogue audio-video jack, 1x USB 2.0, Camera Serial Interface (CSI), Display Serial Interface (DSI)
  • Dimensions: 67×56×11.5 mm

 

 

B+ versus A+

 

Here are some statistics from the test done by guys and girls who make the board  (link below)

 

Sysbench CPU, Lower is better

 

Memory Throughput Higher is better

 

 

If you would like to see the full test see here https://www.raspberrypi.org/magpi/raspberry-pi-specs-benchmarks/

 

As you can see on paper the A+ is pretty damn good and its specs are pretty much the same as the B+ with only a few differences namely the A+ has only one USB 2.0 port and 512Mb of RAM (more on that later)

 

Power and Temperature

 

So for my little project I had to keep a close eye on the power and temperature of the board so I done a few tests checking current draw and temperature under load.

 

Under load it can draw around 2Amp which is pretty hefty when running from a battery back but given the load on the pi (SDR, Screen etc) its to be expected, it can also be to much current draw for some USB power supplies so be careful! An upgrade to this I think will be a sealed lead acid battery with a proper Power distribution setup  to take the strain of the PI

 

Temperature is pretty impressive under load it only reached 67 degrees Celsius with an ambient room temp of 10 degrees. This was with no heatsinks or fans, I was pretty happy.

 

 

Project

 

So some context on what I was using this Pi for. I wanted to build a hack-In-a-box (apparently called Wardriving kits) Basically this is a portable computer system with an SDR (software defined radio) to allow me to research and test vulnerabilities in Radio Frequency communications. I wanted it to be portable so that I can bring it to cyber security conferences to demo common attacks and show off the hidden world of RF.

 

The bill of materals are;

  • Raspberry pi A+
  • 7" touchscreen
  • 5Ah battery pack
  • Nooelec SDR (temporary)
  • USB Hub
  • Pelli Case

 

 

 

 

Small video for anyone who wants it.

 

So this was the Mk1, messy as hell and room for improvement. A big issue with the A+ was the single USB port which gave me a lot of head aches I would have liked to see at least two even if they are mounted on the same bus just to make it easy to plug in a keyboard and mouse, the USB hub I had on hand was cheap and was only able to supply power out of its ports not data which left me with some configuration fun where I had to plug the keyboard in type what I needed and then unplug it and plug in a mouse. If you were using a CLI build this wouldn't be a big issue but I needed the GUI so I was stuck swapping until I got a better USB hub..fun times.

 

I installed Raspbian at first for temperature and hardware testing, I was intending to change this to Ubuntu or Kali Linux (just to be edgy) but I found that Raspbian has a GNU radio package ready to go and the SDR software works pretty well so I was happy to stick with Raspbian for the mean time. The Nooelec SDR I was using, is very low cost only £20 or so, however they are receive only which is fine for information gathering and for most actual attackers this is all they need, they do not want an expensive SDR because most attack devices will be left with or close to the target so they make them cheap and throw-away, using a SDR to gather the data they need to construct the attack device and pre load it with attacks. A future upgrade for this kit will hopefully be a HackRF one which is an SDR designed for just this purpose, there may also be an upgrade of a more industrial SDR for another project setting up a portable GSM base station but that is a story for another day.

 

The Pi held up nicely to prolonged use, with the SDR software running the CPU was settled out around 80% at standard clock speed, with the heatsinks an fans I put onto it they temperatures stayed well nice and cool and given the stress tests I done at the start I think that Pi would be absolutely fine without the added heatsinks

 

 

Summery

 

The A+ Is a great small board with all the bite of the B+ In a smaller form factor.

 

Pros

  • Thermal Performance is impressive
  • Great CPU performance
  • RAM speeds help make up for only having 512mb
  • Most IO Is located in the same place

 

Con

  • Only one USB port
  • 512mb of RAM

 

All In all a great board for the price if you are not limited by USB ports (A small complaint but it kept becoming an issue)

Anonymous
  • Thanks, The SDR I was using was a very cheap one around £30. It is only able to go up to 1GHz so no WiFi or Bluetooth yet, I am planning on upgrading it when funds allow to HackRF one or something similar  to be able to demo more complex attacks. at the moment I have been mostly looking at 433MHz and 868MHz A lot of industrial equipment use these frequency for remote control and to say they are vulnerable to attack would be an understatement.

  • Nice report and done fast.

    What kind of RF frequencies were you observing and signal types ?  WiFi, bluetooth, digital amateur radio bands  ....

    very interesting application

  • I have had a chat with a police officer who was wondering If I was trying to blow something up but a quick talk and some radio license paperwork later and all was good. Yeah temperatures were all gathered with the case open, they way the screen is mounted It cant be used closed. At least for the moment.

  • Always good to see a different approach to a review, well done. Not sure I'd want to be randomly stopped by the police whilst carrying such a case . Were your temperatures measured with the case open?

     

    Rod