raspberry pi 4b 2gb – more working observations

Arduino IDE configured to communicate with Circuit Playground Express

Working with the Raspberry Pi 4B continues. I installed the Arduino IDE version 1.8.9 (https://www.arduino.cc/en/Main/Software) and was able to quickly start it and have it working with a Circuit Playground Express. I found a sample C++ program on GitHub (https://github.com/adafruit/Adafruit_CircuitPlayground/tree/master/examples/FidgetSpinner) and created a simple project, compiling it, but not uploading it. That will come later. I just wanted to check out the basic installation to see if it worked up to a point, and it all does. My only comment is that when you download the IDE that you choose the ARM 32-bit version. It’s a standard tar file, no compression. Once untarred, then execute install.sh. It will not only place everything where it needs to be, but set up permissions, groups, and add a menu entry under Programming.

The IDE seems fully functional. One aspect of using the IDE natively on the RPi 4B with 2GB is that compiles are noticeably slower than they are on my MacBook Pro. But that’s to be expected, and the time taken is not excessive. Just noticeable.

During this period of testing I’ve also managed to force Raspbian to hit the swap space. Unlike the 1GB RPi 4B, the 2GB version’s use of swap is one to two orders less than the 1GB version with the same application load. Right now I’m seeing 4.5MB out of 2GB of swap being used, or essentially next to nothing.

Finally, I installed two more software packages, Swift for ARM and PowerShell Version 7 Preview 2 for ARM.

In order to install Swift on Raspbian Buster, you neeed to add a reference to the repo, then install Swift from that repo. Those steps are:

curl -s https://packagecloud.io/install/repositories/swift-arm/release/script.deb.sh | sudo bash
sudo apt install swift5=5.0.2-v0.4

Once installed you can run this basic test:

pi@raspberrypi:~ $ swiftc --version
Swift version 5.0.2 (swift-5.0.2-RELEASE)
Target: armv6-unknown-linux-gnueabihf
pi@raspberrypi:~ $

You can read about Swift ARM here: https://swift-arm.com/
Note that you should check to see what the current version of Swift ARM is when you install. I chose 5.0.2-v0.4 because that was what was published in the announcement on the web site.

PowerShell Core for Raspbian Buster is available as a regular tar file here: https://github.com/PowerShell/PowerShell/releases

Once downloaded, create a directory on your login home. In my case I simply created ~/powershell. Step into it and untar the newly downloaded archive into the newly created directory. Once untarred simply run pwsh. For example:

pi@raspberrypi:~/powershell $ ./pwsh 
PowerShell 7.0.0-preview.2
Copyright (c) Microsoft Corporation. All rights reserved.

Type 'help' to get help.

PS /home/pi/powershell> $PSVersionTable

Name                           Value
----                           -----
PSVersion                      7.0.0-preview.2
PSEdition                      Core
GitCommitId                    7.0.0-preview.2
OS                             Linux 4.19.58-v7l+ #1245 SMP Fri Jul 12 17:31:45 BST 2019
Platform                       Unix
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.3
WSManStackVersion              3.0

PS /home/pi/powershell> 

And that’s about it.

One more thing. The Flirc case runs warm, but not excessively so. CPU temperatures seem to run between 45°C and 50°C. I’m still working on a 40-pin ribbon cable connector that will easily fit inside the case over the GPIO header.


my second raspberry pi 4 arrived today

New toys arrived today. One of them was a new Raspberry Pi 4.

I ordered a second Raspberry Pi 4 with twice as much memory as the first one, for $10 more. That’s right, the 2GB version costs $45. I picked it up through Adafruit. Once it arrived I pulled out the micro SDXC card I’d been using on the 1GB version and placed it within the 2GB version. Moved over the cables and the wireless keyboard and mouse dongles, plugged in the power, and booted into the Raspbian Buster desktop. With the extra memory it appears to be a bit faster all around.

I still had to program the latest USB firmware into the chip.

As you can see in the screenshot, the amount of swap space was automatically set clamped to 2GB. Based on my simple formula (2 times available memory), it should have been 2 times 1.8GB, or 3.6GB of space. But it’s clamped to 2GB. That’s not a problem as I discovered.

I opened up Chromium and terminal and a number of other desktop applications, and I never touched swap once. I therefore have to recommend that if you want to use the Raspberry Pi 4 as a legitimate desktop, then purchase at least the 2GB version.

I discovered that the processor temperatures are the same as the 1GB version with the heat sinks attached. That tells me the heat sinks I had aren’t useful at all. I ordered a new case from Flirc for the Raspberry Pi 4, one that has a part of the case extend down and touch the processor itself. The case is supposed to act as a big passive heat sink. They’re on sale right now for about $12/case, which is quite affordable. They should arrive next Monday. In the mean time I’ll just leave the box open and let it do its thing uncovered. Oh, I nearly forgot, the Flirc case has a slot cut in the side for the GPIO pins to be connected to external circuitry. Unfortunately for some, there are no slots for the camera cable.