Jul 262014
RPi.GPIO Quick Reference updated for Raspberry Pi B+, A+ and Pi2B

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+ (and A+). Page 3 gives […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 202014
Just How Awesome is the Raspberry Pi Community? Fixing the 'B+ won't shutdown' issue.

On Friday I noticed a bit of ‘weirdness’ happening with my new model B+ Raspberry Pi. When I shut it down with sudo halt it would shut down fine. But when my hand, or the wireless keyboard I was using, got close to the GPIO pins, the Pi would start up again all by itself. I didn’t even need to touch it. Getting close was enough. Let’s Ask the Twitterverse I wasn’t sure if this was a quirk of the B+ or something to do with the dodgy wiring in our house in Poland (not […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…]

Jul 162014
How Much Less Power does the Raspberry Pi B+ use than the old model B?

The power circuit on the new Raspberry Pi B+ has been completely redesigned. It now has an efficient switching regulator. So I decided to take my trusty emeter, a tool I spent far too much money on a few years ago whilst in the grip of the aero-modelling ‘bug’, and make some measurements. I measured the current and voltage going into the Raspberry Pi. The emeter has a calibrated shunt (small blue rectange in the photo with ‘battery’ and ‘load’ at each end) that’s good for up to 20 Amps. This is a way of […more…]

Jul 142014
Raspberry Pi Model B+ Launched Today

Today the Raspberry Pi model B+ is officially announced. It’s a well polished upgrade of the previous model B rev 2. I was fortunate enough to get my hands on one a bit early, so had time to examine, photograph, video and briefly try out the new Pi model B+ with HDMIPi. Here’s what it looks like… What’s New? What’s Changed? The processor and board size are the same, but there are lots of changes. We now have… a metal micro SD card slot on the back. Having previously broken (and fixed) two of the […more…]

Jul 062014
RasPi.Today interview with Alex Eames about HDMIPi, RasPi.TV and RasPiO

A couple of weeks ago, Russell Barnes interviewed me via a skype voice call. We had a half-hour discussion about HDMIPi, RasPi.TV and RasPiO as well as the Raspberry Pi in general and a bit of background stuff that I don’t tend to blog about. Russell is doing a great job with his RasPi.Today podcast and web site. He really did his homework in advance of the interview and in post production. There was definitely a need for a high quality Raspberry Pi based podcast, and I’m glad Russell has decided to fill the gap. […more…]

Jul 022014
Hacking the UNICEF HDMIPi

You may remember seeing the special UNICEF edition HDMIPi, which I blogged about in a guest post on the Raspberry Pi Foundation blog a few weeks ago. This was a temporary solution to get them up and running quickly before the mainstream HDMIPi gets going. It’s a 10″ screen, a bit more expensive than the 9″ regular HDMIPi. It’s currently using a standard driver board. I visited Dave at Cyntech on Monday to discuss various HDMIPi related things. I walked away with one of the UNICEF edition demo HDMIPis, which I decided to take and […more…]