Sep 012014
RPi.GPIO - port function checker

A few weeks ago I blogged about RPi.GPIO updates for the model B and updated my RPi.GPIO documentation and quick reference sheets. But there was one feature I held back on because I needed a bit more time to mess about with it. (And then got busy with other things.) So What Was It? gpio_function() Another RPi.GPIO feature that sneaked in while I wasn’t looking is gpio_function() This is a feature that’s been inserted in RPi.GPIO to enable you to query the setup status of a port to see how it’s configured. import RPi.GPIO as [...more...]

Jul 262014
RPi.GPIO Quick Reference updated for Raspberry Pi B+

Having brought my RPi.GPIO documentation (almost) up-to-date with the previous blog post, I realised it was time to update my RPi.GPIO Quick Reference ‘cheat sheet’ as well. It’s quite a useful reference. Page 1 gives you the basic RPi.GPIO commands and usage. I like to take one of these the Jams in case someone needs help and I can’t remember the necessary commands. Page 2 has a Raspberry Pi GPIO pinout diagram for all versions (except compute module). This part has been updated to add the pinouts for the B+. Page 3 gives a list [...more...]

Jul 252014
RPi.GPIO update and detecting BOTH rising and falling edges

A few days ago, Ben Croston updated the RPi.GPIO Python library so that the ‘board’ pin numbering system would work with all of the pins on the B+. It doesn’t really affect the way I work, as I always use BCM port numbers. They already worked on the B+ and the compute module. While he was at it, he made a couple of bug-fix tweaks. Looking at what was tweaked, I realised there are a couple of features of RPi.GPIO that I hadn’t yet documented. In this blog post I hope to update my RPi.GPIO [...more...]

Jul 182014
Raspberry Pi B+ testing all the GPIO ports

I wanted to check out the GPIO ports on the Raspberry Pi B+. The new B+ has 26 ports available for GPIO work. The previous model B had 17 on the main (P1) header and four more on the now deleted P5 header. The top 26 pins are all the same, but the 14 new pins contain 9 GPIO ports. There’s a full explanation of the ports in the diagram here… How to Test All 26 ports? Why with LEDs of course. You can do it by connecting an LED and resistor (~330 Ohms is [...more...]

Mar 312014
RasPiCamcorder 3 - the PiTFT screen upgrade

Back in December, you might remember I blogged about using Texy’s 2.8″ touchscreen with the Pi camera. At the time I was also aware of the very similar, but slightly more compact, PiTFT by Adafruit. The space for four slim buttons on the PCB made it look ideal. So, this week, when SK Pang tweeted about having PiTFT back in stock, I snapped one up. I also thought I’d put it in a nice case. The Pimoroni PiTFT Pibow looked ideal, so I ordered one of those as well. Both arrived 2 days later. It [...more...]

Feb 112014
Tweeted Photos on a Pi  from the Cambridge Jam

There was a Raspberry Jam in Cambridge on Saturday. I went along to help Carrie-Anne Philbin at the Sonic Pi workshop. I also took the two HDMIPi prototypes to display. Because I’ve been doing a series on making a Twitter App on the Pi, I decided that it’d be fun to use it to tweet some photos live from the event. So, armed with a pre-tested script and the wifi login details, I set it up. And I have to say it worked quite well in the quieter moments when there weren’t millions of people [...more...]

Feb 062014
Tweeting System Information from the Raspberry Pi - part 3 Pi Twitter app series

Today I’m going to show you how to tweet some system information from your Raspberry Pi. In part 2, we did a basic tweet entered at the command line, with a standard, fixed, default message if no tweet text was entered. But That Default Text was Pretty Boring So let’s do something more fun with it. Let’s make it tweet the time, date and processor temperature if you don’t enter any tweet text. I got the ‘tweet the cpu temperature’ idea from Chris Mobberly’s blog. Here’s a condensed code snippet we’re going to borrow from [...more...]

Feb 022014
Tweeting with Python tweepy on the Raspberry Pi - part 2 pi twitter app series

In late October I started a series on Twitter and Python tweepy. Then it got pushed to one side by HDMIPi. But now I’ve managed to find some “recreational” time to play with tweepy a bit more. So in this post, which is part 2, I’m going to show you how to post a tweet using a Python program on the Raspberry Pi. Create Your Twitter App Create a twitter app on your twitter account, as we did in part 1 here Give Your App Permission to Write Then make your app read/write. You won’t [...more...]