Nim on a Raspberry Pi

When the Raspberry Pi 4B came out, something about it peaked my interest… not sure what, as I was certainly aware of the many previous Raspberry Pi models. I always knew about them as the more recent models are manufactured not far from where I live in Wales, so there was a fair bit of news around them from that point of view as well.

It runs Linux by default, using a distro called Raspbian, which is based on Debian. The little computer looked powerful enough to be worth trying out, so I decided to buy one (without much of an expectation) and see what the fuss was about. After a little bit of research I placed an order with The Pi Hut. The Raspberry Pi (RPI) soon turned up in the post, and my next hobby commenced… a year or so later, and now I have three of them!

After trying out various development approaches (perhaps a topic of another post) the Nim programming language caught my interest by accident.

This language has the best of everything in my view, and allows me to quickly build my ideas and projects, using a language that is very similar to Python. The compiled output ends up being very performant, and the source code is easy to maintain, mainly due to its simplicity and clean presentation. Should you write a program you want to use beyond a Raspberry Pi, Nim supports all major operating systems and different CPU architectures, plus the compiled program results in a small mostly static binary.

Nim is certainly a language you should encourage your friends to use!

Why Nim on a Raspberry Pi?

The Raspberry Pi 4B, is a Single Board Computer (SBC) with a four core 1.5Ghz ARM processor, and a choice of 2Gb or 4Gb of RAM. It has a collection of interfaces and ports including WiFi, Bluetooth, USB2, USB3 and Gbit Ethernet. It is therefore certainly a reasonable machine, can be used as a desktop, but is not in the category of a speedy well equipped desktop. But that’s not the point.

To get the best out of the computer, having fast, compiled, binary programs is going to provide the most efficiency. This approach will offer a better use of the computers resources, especially when compared generally to using an interpreted language such as Python, Node.js, etc.

Choosing a language that also compiles to small binary files sizes is better too, so unlike Go (Golang) for example, which produces quite large compiled binaries in comparison to Nim. When the SDCard based storage is slow (compared to a SSD) loading smaller programs into memory when they run will be beneficial too!

Java (and similar such as Clojure, Scala, Kotlin, etc) are nice languages, but while the Java Virtual Machine (JVM) is very fast once running, it does have a load or start up time delay — which if you are programming system tools and utilities is not helpful. Java can also consume quite a bit of a computers memory, which can sometimes be an issue in a resource constrained computer.

Of course Rust and C++ are efficient and fast — but personally I find them more complex and consequently they may have slower development times than Nim for example.

When computing and development is a hobby, having a language such as Nim that offers quick, clean and performant results, it is always nice bonus!

Nim offers the best of lot of areas of consideration. Anyone who currently uses Python (that is popular on a Raspberry Pi already), may enjoy switching to Nim and gaining some additional benefits, without much of a switch over cost time wise.

How to Install Nim on a Raspberry Pi?

Want to try Nim out on a Raspberry Pi?

Luckily there are lots of ways to achieve this, so below are some of the easier methods I know of, including my preferred approach of installing from the Nim source code, and building it my self.

All the options shown below assume you have a Raspberry Pi already installed and working with Raspbian 10.x Buster that can be download from here. Personally my Raspberry Pi all run headless, so they use the Raspbian Buster Lite image, but if you use the desktop version, that should not make any difference to the information outlined below.

Make sure you have a working Raspberry Pi and have access to the command line, before following these steps. Then choose one of the methods outlined - where the third option is my own preference, but does take the longest to complete due to the build process. Not that long though of course!

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1. Install from Raspbian Packages

The most obvious (and probably the easiest) approach is to install using the package manager that is provided with Raspbian called apt. This can be run from a Terminal command line window. To ensure you have the latest package information, first run these two commands, which download the available packages list, and then updates your system with any new software versions, which may include security updates:

sudo apt update
sudo apt -y upgrade

To look at the information and version of the Nim package available use the command:

apt info nim

Currently (16 May 2020) the version of Nim available is very old at version: 0.19.4-1. The current stable version of Nim is: 1.2.0. For that reason I would suggest not installing using this approach, and instead use one of the other options below instead. That way you will get a far more up to date Nim experience!

However, if you do want this older version for some reason, the command to install it would be:

sudo apt get install nim nim-doc

Hopefully, the Nim package maintainer will bring the available Raspbian package back up to date soon, and this method of installation will be more suitable.

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2. Install with the ‘choosenim’ tool

choosenim is a tool written by Dominik Picheta who is the author of the great Nim in Action book. As it states on the publishers web site:

Dominik Picheta is one of the principal developers of Nim and author of the Nimble package manager.

What choosenim can do is not only install the nim compiler onto a Raspberry Pi, but also then manage the process of keeping it up to date, manage the use of different Nim compiler versions, and more.

Before installing and using choosenim it is worth making sure the Nim dependencies are installed in Raspbian first. This can be done with the following commands.

In a Terminal command line window, first update the packages, and then ensure your Raspberry Pi has the latest packages and security fixes installed too:

sudo apt update
sudo apt -y upgrade

Now install the the build-essential meta package which will install the GCC compiler, and other basic C language tools needed by Nim. The openssl library may already be installed, but it does no harm to double check, and the curl program is needed in the next step to download and run the choosnim installation:

sudo apt -y install build-essential openssl curl

You can now follow the instructions provided on the choosenim site. For Unix (such as Raspbian) the following command should commence the installation:

curl https://nim-lang.org/choosenim/init.sh -sSf | sh

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3. Install by compiling Nim from source

The instructions below are my preferred method of installing Nim on a Raspberry Pi. Although it takes a bit longer, as it does a complete build of the compiler and supporting tools, it is a good way to have an insight into how the Nim compiler is created.

Before building from source, the Nim dependencies need to be installed in Raspbian first. This can be done with the following commands.

In a Terminal command line window, first update the packages list, and ensure your Raspberry Pi has the latest packages and security fixes installed too:

sudo apt update
sudo apt -y upgrade

Now install the the build-essential meta package which will install the GCC compiler, and other basic C language tools needed by Nim. The openssl library may already be installed, but it does no harm to double check, and the curl program is needed in the next step to download the source code from the Nim web site:

sudo apt -y install build-essential openssl curl

The Nim source code is already bundled up in a format ready to be built, and can be obtained from the Nim Unix download page.

You should check the ‘Source archive’ link on the above page, and if needed change to the latest stable version available. Currently the linked file name is for source code version: nim-1.2.0.tar.xz.

The steps below create a new directory called scratch in you home directory, change into that directory, and then it uses curl to downloaded the source code file to your Raspberry Pi. The tar command then extracts the archives contents, and the final command changes into that new directory containing the Nim source code:

cd ~
mkdir scratch
cd scratch
curl https://nim-lang.org/download/nim-1.2.0.tar.xz -O
tar -xJvf nim-1.2.0.tar.xz
cd nim-1.2.0

Now the actual build process can begin! First run the command to commence the build:

./build.sh

Once that completes, the build of the koch program can be done with an existing older supplied version of the Nim compiler with the command:

bin/nim c koch

The newly created koch tool can now be used to compile so supporting tools:

./koch tools

Next, run the command with koch to create the nimble package manager tool:

./koch nimble

Now, using the Nim provided install.sh script, install everything into: $HOME/.nimble directory. The second step below also copies the Nim tools into the same location as the Nim compiler as well:

sh ./install.sh $HOME/.nimble
cp ./bin/* $HOME/.nimble/nim/bin/

Next it is worth updating the nimble package managers package manifest, and then using nimble to update itself to the latest version. The last command moves the original (older) version of the nimble program to be called nimble-orig. That way the newer version is run instead of the older one, that was built from the source code downloaded. Run these three steps as:

nimble refresh -y
nimble install -y nimble
mv $HOME/.nimble/nim/bin/nimble $HOME/.nimble/nim/bin/nimble-orig

To ensure the nim compiler and supporting tools, plus nimble that were all built on the Raspberry Pi computer are available in your PATH, run the command:

export PATH="${PATH}":$HOME/.nimble/nim/bin:$HOME/.nimble/bin

The above line should also be added to your you ~.profile or ~.bashrc file (or equivalent for other shells) so that the PATH is updated each time you login.

That’s it!

You should now have a nice pristine new stable version of Nim tools, the nim compiler, and the nimble package manager. To check they are working, their version numbers can be displayed with the following commands:

nim --version
nimble --version

If you would prefer to perform all the above steps in a single command, I run them using a bash script called: nim-install.sh. This can be found in my GitHub repo.

If you wanted to use it, it can be download, and then run using the commands:

mkdir ~/scratch
cd ~/scratch
curl https://raw.githubusercontent.com/wiremoons/GenIsys-Pi4/master/install/nim-install.sh -O
chmod 755 ./nim-install.sh
./nim-install.sh

Once run, you will still needed to change your PATH in your you ~.profile or ~.bashrc files as outlined above.

If you want some more setup examples, my above GitHub repo called ‘GenIsys-Pi4’ contains all the files I clone onto a Raspberry Pi when is set it up from a fresh Raspbian install.

The Nim web site Unix install page also has plenty of helpful information, and offers more alternative install options such as using docker or snaps too.

Update

It was pointed out to me on the Nim forum that there are also pre-complied Nim binaries for many different platforms, including the Raspberry Pi, available from the Nim Github release pages. Just in case you don’t want to use one of the above build it yourself options!

What Next?

Now you have the latest stable version of Nim installed, you can start to develop your own programs. There are some very good tutorials on the Nim ‘Learn’ section of the Nim web site.

A fairly simple Nim program I wrote is used to check the CPU temperature of my Raspberry Pi. For more information see the page here: systemp

If you want to find out more about Nim, visit the great web site pages here: Nim language site or if you need more help, the Nim Forum is a friendly and supportive community location to call on.

Article Details

• Title: Nim on a Raspberry Pi
• Published Date : 16 May 2020