There maybe times when you want to run a Python script when your Raspberry Pi boots up. There are a number of different techniques to do this but I prefer the method that uses “cron”. Cron is a job scheduler that allows the system to perform tasks at defined times or intervals. It is a very powerful tool and useful in lots of situations. You can use it to run commands or in this case, a Python script.
Author: Matt
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Since they opened a Poundworld a mile from my house I can’t help but pop in there and see what they’ve got when I’m passing. It’s a relaxing shopping experience because there are no surprises. You never pick something up only to be shocked at an unexpected price. Whatever you see is a £1 ($1.50). Not a penny more or penny less. (Very similar to Poundland!). So here are a few bits I picked up to stick in my Raspberry Pi project box. A bluetooth dongle, an SD card reader and a USB LED flexible light. All for the princely…
In a recent article I mentioned how you can add cheap interchangeable lenses to your Raspberry Pi camera to make it more versatile. I’ve now played around with the macro lens and thought I’d show you a set of photos I took. My son is really interested in insects so I decided to take some macro photos of whatever I could find behind the sofa. The lucky subjects were a moth and some sort of fly which we found in the conservatory (someone had vacuumed under the sofa!).
One of the great things about the Raspberry Pi is that it is easy to go portable. What is even better is that because the Pi can accept 5V it will work with lots of power accessories designed for mobile phones and tablets. In previous posts I have run a few of my Raspberry Pis from standard AA batteries and a generic Li-on Power Pack. This week I tested a RAVPower 10400mAh Power Bank to see how long it could power a Pi running my standard battery test. RAVPower Power Bank (RP-PB07) The RP-PB07 (also known as Dynamo On-the-Go Power…
It was a lovely summer’s day in Bristol and something slightly unusual was going on in town. 80 Gromit statues were being deployed as part of the “Gromit Unleashed” public art exhibition. This is a charity event led by Aardman Animations to raise money for Bristol Childrens’ Hospital. So it seemed like the perfect chance to try out my Raspberry Pi camera unit as there would be plenty of things to take photos of. My equipment consisted of : Raspberry Pi and camera module 6 Sanyo eneloop AA batteries Hobbyking 5V UBEC Modified case with power switch, 3 microswitches and…
I discovered on eBay that you could buy lenses designed to be attached to a mobile phone. They cost £6.99 and included a wide angle, fish eye and macro lens so I decided to take a gamble and order a set. The lenses themselves are magnetic and attach to mobile phones with a metal ring around the camera. Some sticky metal rings are supplied to allow you to add a ring to your phone which the lenses can attach to. So I stuck an 8mm washer to the front of my Raspberry Pi point-and-shoot camera and found the lenses were…
It’s easy taking photos using the Pi camera module using the excellent raspistill command line utility or the PiCamera Python library. I wanted to experiment with the different settings available for EX (Exposure) and AWB (Auto White Balance) and see how they performed in different environments. Trying different settings manually seemed like a lot of work so I decided to write some scripts that would take a sequence of photos using all available options. I could then quickly review the photos and see which ones looked best in a particular environment. The scripts could be used whenever I needed to…
In my previous battery tests I’ve stuck to AA batteries. Mainly because I’ve got lots of them and I like their versatility. Recently I decided to buy a portable Li-on battery pack designed for recharging mobile phones and tablets while on the move. Given I could use it for portable Raspberry Pi projects and charging mobile devices it seemed like a good thing to buy. So I picked one from eBay. If you are going to have one you might as well have a big one so I opted for a device with a stated capacity of 12000mAh. It has…
If you need to play video files and you don’t want to install a full media solution such as XBMC then you can play them directly from the command line using Omxplayer. This is a media player created by Edgar Hucek specifically for the Raspberry Pi and it takes advantage of the Pi’s GPU. Installation Omxplayer is installed on the latest Raspbian image so you may already have it installed. If not you can install it using : sudo apt-get update sudo apt-get -y install omxplayer
This page aims to summarise the steps required to install a webserver with PHP support onto your Raspberry Pi. This will allow the Pi to server HTML and PHP pages to users on the same network. This is a useful mechanism to view images and/or data on the Pi from another device, whether that is a PC, laptop, tablet or mobile phone. Note : Before experimenting with network enabled features you should really make sure you have changed your Pi password from the “raspberry” default.
Things have moved on a bit with the Raspbian image since I wrote my Raspberry Pi Speakers & Analog Sound Test post. So I decided to take another look as I wanted to start adding some audio to my experiments. I’m making slow progress with my remote controlled car project but I figured I might as well shoe-horn some audio in there as well. One thing that has changed in the latest Raspian image is that the alsa sound drivers have improved and are enabled by default. So I decided to hook up a rechargeable powered speaker I had using…
The purpose of this post is to demonstrate how to add a logo to your time-lapse videos. The logo can be any graphic you can create and could easily be a watermark or text. The objective was to add my Raspberry Pi Spy logo to the bottom corner of a video at the same time I rendered my timelapse videos from the source images. This article assume you’ve correctly installed your camera module and had a play with taking photos with it. Here is a list of the hardware and software I used : Raspberry Pi camera module connected to…
In this post I will explain how I made some timelapse videos using the Raspberry Pi camera module. This is a two step process which involves getting the camera module to take a series of stills over a period of time and then combining them into an MP4 video file. We can use the “raspistill” utility to take a set of time lapsed photos as described in my Taking Hi-Res Photos With The Pi Camera Module article. Make sure you have installed the camera and updated your operating system.
Not only can the Raspberry Pi camera capture photos but it can also capture full HD video at 1920×1080. The official camera module has been optimised to use the full hardware media capabilities of the Pi’s processor which allows it to handle video that a standard 700MHz would struggle to process. To capture video you can use the “raspivid” utility. This should be available on the Pi assuming you followed my Installing The Raspberry Pi Camera Module guide and upgraded your operating system.
Taking photos with the Pi Camera Module is easy once you have plugged it in and made the correct configuration changes. In order to do this make sure you have read my Installing The Raspberry Pi Camera Module page. Once you’ve completed the camera installation you won’t need to do it again and you can concentrate on taking photos and recording HD video.
The Official Raspberry Pi camera module is here at last. The full specification can be found on my Official Raspberry Pi Camera Module page. This page aims to show how to get the camera connected and ready to go. Depending on the current state of your SD card this will take between 2 and 20 minutes.
The Pi camera module includes a red LED in one corner of the PCB. This lights up when the camera is active. It’s really useful in giving a visual indication that the camera is doing something and most of the time you will be glad it is there. However there are a number of reasons you might wish it wasn’t. In my testing here are some of the reasons it can get in the way : It can cause reflections on objects you are trying to photograph giving them a red glow. For nature photography it scares animals. For security…
Having played around with the Pi camera I quickly realised I needed to make some sort of stand for it. The module weighs almost nothing and is tiny so it can be quite hard to keep in one place when you are experimenting. The Raspberry Pi Foundation apparently recommends Blu-tack, based on cost, simplicity and plain, old fashioned versatility.
The first add-on from the Raspberry Pi Foundation is the official camera module “RaspiCam”. It’s been a long time coming but it is finally available to buy from Farnell, CPC (order code SC13023) and RS. The module attaches directly to the Pi PCB via a ribbon cable and the CSI connector. The camera module is an OV5647 made by OmniVision and measures 8.5 x 8.5 x 5mm. The whole unit including the PCB measures 25mm x 20mm x 9mm. The camera contains a fixed focus 5-megapixel CMOS image sensor and is capable of recording 720p and 1080p HD video at…
While wandering the internet I found an article Raspberry Pi: CPU usage monitoring using GPIO by chteuchteu. This explained how to display the current CPU usage on 7 LEDs attached to the GPIO header. I thought this would be a great application to convert for use with a BerryClip 6 LED Buzzer board. So I modified the original code to use 6 LEDs and tweaked a few of the functions. Apart from the LED count I changed the script to use an array of GPIO references so it would be easier to update if you used different pins.
Having previously run my Raspberry Pi from a set of AA batteries I decided to test all the different types I had available to see which ones lasted the longest. This wasn’t going to be a scientific test but I wanted a general feeling for how the batteries performed given their different capabilities and price. The batteries I decided to try were : Sanyo eneloop (2000mAh) Sanyo eneloop XX (2550mAh) 7DayShop Rechargeables (2900mAh) 7DayShop “Good to Go” Rechargeables (2150mAh) Maxell Alkaline Non-Rechargeables Due to the time required to run the tests and re-charge the batteries I opted for running the…
The Bristol Mini Maker Faire was held on 23rd March 2013 at the M Shed on the waterfront. It was my first maker faire and my main objective was to hear Eben Upton from the Raspberry Pi Foundation speak. The traffic conditions resulted in his talk being delayed by one hour which gave me, my wife and my son a bit more time to look around.