Shrink/Expand Raspberry Pi Filesystem Images

Shrink/Expand Raspberry Pi Filesystem Images

This post documents a few tricks I found useful when making SD card images for Raspberry Pi projects, to minimize file size and download times while making full use of the SD card space. These instructions work for Raspbian Stretch images; not sure about older or newer versions.

The first time a Raspbian system boots, it runs a program to expand the filesystem to use the full size of the SD card. So, when you are using a Raspberry Pi system you automatically get the benefit of the full (e.g., 8GB) SD card size. The problem is that when you copy the card image you copy the whole 8GB, even if only 2GB is in use. That takes up a lot of unneeded space, and lengthens download times.

So, the first task is to reduce the size of the image to a minimum.

Raspeberry Pi updates

Open the Terminal app on your Raspeberry Pi, then run each command below:


sudo apt-get update --fix-missing
sudo apt-get upgrade --fix-missing


sudo apt-get update.
sudo apt-get dist-upgrade.
sudo apt-get install -y rpi-chromium-mods.
sudo apt-get install -y python-sense-emu python3-sense-emu.
sudo apt-get install -y python-sense-emu-doc realvnc-vnc-viewer.

Update your Raspberry Pi to Raspbian Pixel for fancy new features

Utilizing all cores on Raspberry Pi 3

Utilizing all cores on Raspberry Pi 3

I was wondering if there is a simple way to "turn on" all 100% of the CPU so that I can run processes faster (such as python calculations).

1) Is this possible?

2) Is there an easy way to revert back to normal?

3) Is there a way to use less CPU if desired?

I'm thinking of a command line interaction like:

pi@raspberry:~ $ sudo turnOnFourCores python run.py


Raspberry PI overclocking parameters in CONFIG.TXT

Raspberry PI overclocking parameters in CONFIG.TXT

NOTE: Setting any overclocking parameters to values other than those used by raspi-config may set a permanent bit within the SoC, making it possible to detect that your Pi has been overclocked. The specific circumstances where the overclock bit is set are if force_turbo is set to 1 and any of the over_voltage_* options are set to a value > 0. See the blog post on Turbo Mode for more information.

The latest kernel has a cpufreq kernel driver with the "ondemand" governor enabled by default. It has no effect if you have no overclock settings, but if you overclock, the CPU frequency will vary with processor load. Non-default values are only used when required, according to the governor. You can adjust the minimum values with the *_min config options, or disable dynamic clocking (and force overclocking) with force_turbo=1. For more information see here.


Headless Rasp Pi Zero w

I have just loaded headless raspbian stretch lite on to a Pi Zero W. I had problems trying to run it ssh, so connected screen keyboard etc. It boots fine, with the
pi@raspberrypi: "$
prompt, but if I do an ls to see the files it doesn't come back with any files. Is this correct?

Is there any free VPN service for Raspberry Pi 3(instead of PiVPN)

Is there any free VPN service for Raspberry Pi 3(instead of PiVPN)

Hello there, i have a Raspberry Pi 3 and i am using it with my TV. At the past, i heard about some hackers log in to Pi with bots using ip adresses. I was using raspberry pi as a normal pc so i was doing all my work in it(office works, web browsing etc.) after i hear theese news, i started using it lesser and lesser. Because i am connected to internet, i have my port 22, 23 and a few other ports open for some projects i have. So i need to hide my ip while i'm browsing in internet. So, is there any free VPN services for Raspberry Pi that i can use?(I am new in forum but i have been using Raspberry Pi's since 2016)


If you are running Raspbian and have changed the default password to something secure (not easy to guess or brute force) then your Pi is no more vulnerable than any other computer running Debian Linux (which is more secure than Windows). If you want a bit more security, change the username as well. I create my own user and disable the default pi account with sudo passwd --lock pi (I change the default hostname as well).

Raspberry Pi computers that get hacked are usually the ones that go online with the default username and password.

It's also not advised to open default ports (like port 22 for SSH). Use port forwarding instead (forward a normally unused port to port 22 in your router and use that port number for external SSH connections).


Raspberry pi 4 announced

The Raspberry Pi Foundation has not announced any details of a Pi 4, and they generally do not pre-announce things, and asking for hints just annoys them. The tea leaves say that most of the changes that folks would want to see (USB3, more RAM, etc.) will require building an entirely new SoC (the chip that provides nearly all the functionality of the Pi: CPU, GPU, etc), and that task is neither cheap nor quick, so don't hold your breath.

What we do know: the CM3 just got released, and the Foundation is on record that a Pi 3A (effectively a Pi A+ with the Pi 3B's SoC) will be along "soon" after the CM3 (for unspecified values of "soon"). Anything beyond that is merely speculation.

The Pi 3B and Pi Zero are remarkable little machines - get one, or several, and enjoy making them do neat things now, and be happily surprised when the Pi 4 arrives someday. They are known to be i/o bandwidth limited, but can do some really interesting things.

Raspberry Pi 3 WiFI hotspot?

I want to create a hotspot with my new rpi 3. But I cant get the build in wifi module in the master mode (AP)
Are there any drivers available for the rpi 3 wifi module to setup an hotspot?


Would you like to use your Pi as a WiFi router? Or maybe have it as a special filtering access point? Setting up a Pi as an access point (AP) is a bit more advanced than using it as a client, but its still only a half hour of typing to configure. If you want to, this tutorial will make it so the Pi broadcasts a WiFi service and then routes internet traffic to an Ethernet cable. Since its all Linux you can go in and update or configure it however you like.

I used the following pages as a guide to create this tutorial, please note many of them will not work completely, but check them out if you are interested!

Raspberry Pi with 12 VDC

Installing a Barrel Connector on Your UDRC

The UDRC can be powered directly by a 12 VDC source.

When powering via 12 VDC, the UDRC™ will also power the attached Raspberry Pi 2 or 3.

Installing a Barrel Connector on Your UDRC




Headless Voice Activated Google Assistant on Raspberry Pi

Headless setup: no keyboard, display or frustration

This is a step-by-step guide of how to set up your Raspberry Pi from scratch. It assumes that you want to run "headless", that is, access it via network connections without a keyboard or display. This guide uses Raspbian, the "Debian Wheezy" version of Linux.


TNC-X for Raspberry Pi

TNC-X for Raspberry Pi
Have Your Pi a la mode!

The Official Raspberry Pi Touch Display has now been released. For information on using it to build your own portable APRS Tracker using Xastir check here!

There is now a new version of the TNC-Pi designed to fit the Raspberry Pi model B+, Pi 2 and Pi 3 perfectly! See below for details!