The Raspberry Pi Foundation has soft-launched a whole series of guides for using the Raspberry Pi and various add-ons. The guides are as follows:
Great resources, well worth reading for beginners.
Bare Conductive’s Pi Cap proves to be a versatile Raspberry Pi add-on
Bare Conductive Pi Cap – photograph by Adafruit
Bare Conductive’s Pi Cap is an add-on board for the Raspberry Pi that plugs into the GPIO pins. It provides the following features:
- 12 conductive crocodile clip-compatible connection points
- High quality audio output via a 3.5mm jack
- A user-programmable RGB LED
- A tiny button
- 7 unused GPIO pins broken out
- A prototyping area
It is compatible with any of the 40-pin Raspberry Pis and comes with extensive programming libraries written in Python, C++ and NodeJS.
Bare Conductive were kind enough to send me one of their Pi Caps and I’ve spent a few hours trying it out. I have to say I’m very impressed. It’s an interesting mixture of hardware features, certainly. In fact, at first glance the 3.5mm jack in particular seems like an odd addition. However, a closer look at some of the example scripts provided gives you a glimpse at the ways you could use the jack in combination with the conductive inputs.
Installing the software is an easy process – a simple apt-get command and another setup command after that – and they provide great instructions online to get you going from first principals such as burning an operating system image onto an SD card to using the tutorial script provided. Speaking of which, the tutorial script is ingenious – it’s a text-based to some of the examples provided and you can see them working by touching the capacitive inputs. This gives you an ‘instant win’ in terms of seeing the hardware working. The example code is well thought-outand useful and it shouldn’t take much for a beginner programmer to unpick the code and bend it to their own uses.
The capacitive inputs work by touching the pads with your finger, or by connecting up conductive objects (bananas come to mind!) to the inputs. I used conductive ink to draw a line on the back of an envelope and connected a crocodile clip from the pad to the ink. That way, when I touched the ink the conductive input registered the touch. Just the job for simple experiments.
Breaking out the unused pins is, of course, a winner for any hacker of hardware, so this is good to see. 7 GPIOs should be enough to add LEDs, switches, even a buzzer and the prototyping area keeps everything neat. The addition of a tiny button on the side is a bit useless, but I guess good if you need it. The only negative thing I can say is that the button is on the inner side of the board so you need a pencil or something to reach it past the USB ports.
The 3.5mm jack for audio provides a high-quality line-out output from the Pi. As I’ve said before, this may seem a strange addition but they provide an example of using the touch inputs to play sound, so turning the Pi Cap into a musical instrument with decent quality audio is a real possibility.
The price, £28, is a bit steep for an add-on board for the Pi, however there are such a lot of features, and the board is so versatile in terms of what you can use for inputs that I think it’s well worth it.
Thoroughly recommended.
You can buy the Pi Cap from Bare Conductive or The Pi Hut for around £28.
ZeroSeg from The Pi Hut / Average Man for the Raspberry Pi – review
A little while ago, The Pi Hut announced the launch of the ZeroSeg add-on board for the Raspberry Pi. I ordered one but it’s not until now that I managed to actually solder it up and have a play. So, let’s see what you get.
It’s a Zero-sized add-on board which houses two 4-character, 7-segment displays running from a MAX7219CNG integrated chip. It comes in kit form and requires soldering. What? I hear you cry. Soldering? Run for the hills! Now, calm down, it isn’t that bad! 🙂 As a kit, it’s a fair amount of soldering, but it’s what I would call beginners-level soldering. To be frank, the most difficult part is working out which resistor is which! All the components have their correct place and the assembly instructions [PDF] are absolutely first-rate. Richard Saville (Average Man) who designed the board clearly knows the Pi market well – we’re not all experts, and we need clear instructions to put things together. The instructions are heavily illustrated with photographs and the order you need to work in is stated clearly.
It comes with a software library and instructions for installing it.
So what did I think of it?
The hardware is excellent. As previously stated, the instructions for soldering it all together are top-notch with photographs and a clear, sensible order of assembly. Everything fits together well and you’d be hard-pushed to get a piece of tissue paper between the two 7-seg displays: they’re that well-fitting. The most difficult part of assembling any board with a chip on it is getting the legs of the chip to fit in the socket (or directly into the board if there is no socket). It proves to be so with this board, and the trick is to ‘roll’ the chip on a flat surface and push the legs in bit by bit until you get a good match to the socket or holes. I had no problems assembling the ZeroSeg: be careful with the soldering iron and everything will be fine.
Installation of the software is simple, with clear instructions, but a little bit manual for my liking and I would have liked to have seen a simple downloadable script piped through to the shell. It’s just a personal preference, though, and the instructions work just fine.
The software library is good and there are plenty of examples to get you started on displaying text, scrolling text and using the buttons. The buttons are even easier to use if you use GPIO Zero rather than straight RPi.GPIO, but an example isn’t given. Perhaps this could be added for simplicity, but again, I don’t really have any complaints.
Conclusion
If you’re looking for some way of displaying simple text and numbers, this is a good solution, especially at the price of just £10. Be aware that some characters (for instance W and M) are replaced by underscores as it’s just not possible to display them on 7-seg displays. The ZeroSeg, therefore, works best as a strictly numerical display. Richard has done a nice example of using the ZeroSeg to display stats from his WordPress blog which you can see here. I’m really glad I’ve had a chance to look at this add-on board, and I’m looking forward to finding a good use for it attached to a Pi Zero, perhaps mounted on the wall somehow!
The ZeroSeg is available to buy from The Pi Hut for £10.
Self-playing wooden pipe organ uses a Raspberry Pi and Arduino
Wendell Kapustiak has built a self-playing wooden pipe organ. The organ has 42 wooden pipes (representing 3.5 chromatic octaves). Each wooden pipe is different and had to be custom-cut to play the right note. A “blower” used to cool data centres was modified to keep it quiet and enclosed; air pressure from the blower feeds the organ’s wind chest which provides the air for the pipes. The valves for the pipes (which cause them to ‘play’) are opened and closed using solenoids. The main processor is a Raspberry Pi which provides a user interface for selecting songs and sends MIDI instructions to an Arduino Due which has a pin assigned for each pipe. A transistor board boosts the activation signal so that the solenoids fire. It certainly makes a beautiful sound in full flow. You can see it in action in the video above, which features an interview with Wendell, and you can read more about the build over on his blog.
New Zealand student develops plane tracking system using QR codes and a Raspberry Pi
Benjamin explains his project at ASB
Inspired by the 2014 disappearance of flight MH370, New Zealand year 8 student Benjamin Mueggenburg has developed what he calls a Visual Plane Locating System. It is designed to overcome some of the problems with the existing system of tracking planes, namely RADAR. The system uses a Raspberry Pi and a webcam to simulate an orbiting satellite. The “satellite” looks down on the Earth and identifies planes (represented by toy planes in Benjamin’s project) by scanning QR codes on their wings. The project won him two top ASB Bright Sparks prizes for “best in junior science” and “best junior concept”. You can read a short interview with him over at ASB and watch a video of his project below.
2nd German edition issue of Raspberry Pi magazine The MagPi now available to buy
Raspberry Pi recently announced that The MagPi would be available in a bi-monthly German translation edition. The second issue, translated by the people at CHIP, is now available. It’s 100 pages long and costs €9.95 in print or €6.50 on digital devices. You can buy it online here.