By default Raspbian configures the Raspberry Pi serial port (GPIO14-GPIO15) to provide boot-up information. It also allows you to login via a connected device. If you need to use the Pi’s serial port for something else (i.e. a specific add-on board) you will need to disable this default functionality. It’s something I needed to do when I played with the Ciseco Pi-Lite and luckily isn’t too difficult as the instructions below will hopefully show.
Author: Matt
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In my Introduction to the GertDuino I explained how it allows the Pi to compile and send code to an Atmega328 micro-controller. In this post I will explain the steps you need to take to get it up and running with an example program called “blink”. The example is fairly basic and turns on the onboard blue LEDs. Once completed you will have a working system ready for your own experiments. When I started I had never used an Arduino so hopefully this post will help simplify some of things that confused me when I took the board out of…
I’ve just recently got hold of a new board by Gert van Loo, the volunteer engineer who helped design the Raspberry Pi. It’s the GertDuino and follows in the footsteps of the Gertboard. The GertDuino is a an Arduino based add-on board for the Raspberry Pi. It offers the same features as an Arduino Uno but with some additional functionality. What is an Arduino you might be thinking? Well take a look at the Wikipedia page to find out. I’ve never used an Arduino so this seems like a good place to start. I will create blog posts as I…
Today I went to the DigiMakers (aka Raspberry Pi Boot Camp) event held in the @Bristol Science Centre. I had booked a place for my son on the “Controlling a Robotic Rover with Scratch” workshop run by Alan from Dawn Robotics. The workshop was an hour and a half long and aimed to introduce using Scratch to control a Raspberry Pi powered vehicle. The vehicle had to move around its environment and locate an “artefact” which was in an unknown location. The rover had a camera and was capable of recognising black and white patterns using some basic computer vision.
If I need to edit text files directly on my Raspberry Pi my text editor of choice is nano. There are other text editors available but I prefer nano’s relatively straightforward interface. As a command line based utility it may feel strange for users who are more familiar with a graphical interface but it is easy to learn the basics. Syntax colouring is available which makes reading and reviewing scripts easy.
As soon as I ordered some Pi NoIR camera modules I also ordered some bits and pieces for testing. This included some standard IR LEDs and a couple of cheap IR CCTV illuminators. These would allow me to test with the camera module and work out what sort of IR lighting I needed for different applications. Ideally I was looking for suitable lighting for an outdoor security camera and I wanted to workout if it would be easier to use ready made lights or make my own.
The Raspberry Pi camera has been available for a while now and it has resulted in plenty of camera based projects. Like many camera modules it is fitted with an infrared (IR) filter which is there to improve overall image quality. Humans can’t see infrared so it most cases it is better to filter it out and tune the camera to visible light. Most webcams use a similar technique. However this reduces the usefulness of the camera module in some applications. Many webcams can have the filter removed with a bit of hacking but this wasn’t very easy with the…
The Raspberry Pi has no built in analogue inputs which means it is a bit of a pain to use many of the available sensors. I wanted to update my garage security system with the ability to use more sensors so I decided to investigate an easy and cheap way to do it. The MCP3008 was the answer. The MCP3008 is a 10bit 8-channel Analogue-to-digital converter (ADC). It is cheap, easy to connect and doesn’t require any additional components. It uses the SPI bus protocol which is supported by the Pi’s GPIO header. This article explains how to use an…
“Adventures in Raspberry Pi” is a book by Carrie Anne Philbin, a valued member of the Raspberry Pi community. Miss Philbin is a secondary school teacher of computing so knows a thing or two about the challenges of teaching kids computer programming. Her book aims to teach computer programming and some system administration skills to kids using the Pi. No previous knowledge is assumed so is suitable for everyone. The book is written with 11-15 year olds in mind but I suspect it will be useful for a younger audience with appropriate support.
It’s that time of year when mad inventors start creating Halloween themed electronics projects. I’ve never managed to be organised to do a seasonal project but this year I decided to give it a try. So this year I decided to take what I’ve learnt about the Pi-Lite and create a simple Halloween project I can stick in the window along side our more traditional carved pumpkins.
In my previous post about the Pi-Lite I explained how to set it up and how you could display scrolling text in Python. In this post I will explain how to create custom 14×9 pictures and then send them to the Pi-Lite. This is the same technique used to create the Pac Man image to the right. The Pi-Lite has a frame buffer feature which allows you to send it data which determines the state of each LED. You can set each LED to be on or off and once all your data has been received the Pi-Lite sets the…
Creating a Raspberry Pi screenshot is useful if you need to keep a record of your project or share details with others. You can capture screen grabs using a command line utility called Scrot. It is easy to use and provides lots of options. It allows delayed captures and the ability to choose the capture area with the mouse. Scrot Installation If you are using the latest version of Rapberry Pi OS then scrot may already be installed and mapped to the “PrtScn” key. Press the “PrtScn” and check if a png file has appeared in your home (/home/pi) directory.…
Until recently I had never played Minecraft but it’s popularity meant it was something I felt I had to try. I installed the free pocket edition on my Nexus 7 to try it out and as a result decided to give it a go on the Pi.
On the 21st September I made my way from Bristol to Cambridge for a Raspberry Jam. It was quite a long journey but was worth it. I didn’t really plan on buying anything while I was there as I didn’t need anything. However, that was before I saw the tempting range of Pi items available from the vendors. So here is a quick summary of the various bits and pieces I walked away with.
If you’ve followed the previous Pi-Lite setup article you should have a working Pi-Lite. The example Python scripts are great but I wanted to show a simple example of my own demonstrating the basics of sending scrolling text to the Pi-Lite. Scrolling text is something that the on-board microcontroller handles for you so it really doesn’t involve much effort to do using a short Python script. The following script scrolls two messages to demonstrate the technique.
Back in 2013 I purchased a Pi-Lite at the Cambridge Raspberry Pi Jam.This is a 14×9 matrix of red LEDs mounted on a PCB that can be attached to the Pi and controlled via the GPIO header. The 126 LEDs can be turned on individually or used to display scrolling text. Although there was plenty of help material available from the Openmicros.org site (no longer available) I found it a little bit confusing. Information was spread over a mixture of pages and it was easy to get lost in the more advanced detail while looking for a gentle introduction. So…
Yesterday I went to the Raspberry Jam in Cambridge. This was 170 miles from my home but I thought it would be nice to visit the birthplace of the Raspberry Pi and meet some of the Pi enthusiasts who I follow on Twitter and various other virtual environments. Once I dropped my wife and son in town I arrived at about mid day which left me with a bit of time to setup the various Pi projects I had bought with me to display in the show-n-tell area. My friend Graham from RaspberryPiSchool.org.uk had already setup the table so all…
The OpenElectrons “PiPan” is a pan and tilt mechanism for the Raspberry Pi Camera Module. I’ve used the Pi camera in a few projects but this is the first bit of commercial Pi camera hardware I’ve had the chance to play with. The project was successfully funded on Kickstarter on 11th September 2013. It consists of a kit which when assembled allows you to move your camera in both horizontal and vertical directions. To achieve this is uses two small servos and a control board which can be controlled using Python. It can pan 180 degrees (from left to right)…
I’ve recently got hold of a Perixx 804 Bluetooth keyboard which I plan to use with my tablet for typing and future Raspberry Pi projects. I chose the Perixx 804 as it uses a UK keyboard layout. The black version is a standard PC layout (” on the 2 key) whereas the silver version uses an Apple style layout (@ on the 2 key). This tutorial will explain how to pair this with your Raspberry Pi. While developing this tutorial I used the black version with the PC-style UK layout as this is the layout I use everyday on my…
In How To Use A MCP23017 I2C Port Expander With The Raspberry Pi – Part 2 I explained how to use an MCP23017 16-bit port expander to provide additional outputs. In this article I’ll show a basic input example where we read the status of a push switch. In our example circuit the switch input uses the last bit of the GPA set of pins.
In How To Use A MCP23017 I2C Port Expander With The Raspberry Pi – Part 1 I explained how to configure your Pi to use I2C so you could connect an MCP23017 16-bit port expander to it. If you’ve followed that article and got your circuit ready you are only a few steps away from controlling the chip using a simple Python script.
For all of my projects I have used the standard GPIO header pins as inputs and outputs. This gives you a total of 17 pins to play with but what if you need more? The easiest way of getting more inputs and outputs is to use an “i/o port expander”. This is a device that allows you to control a number of ports using data you send to the device.