Raspberry Pi lends a hand to stop this robot falling over

Kris Hauser is an associate professor of electrical and computer engineering, and of mechanical engineering and materials science at Duke University’s Pratt School of Engineering. He has developed an algorithm that effectively stops a bipedal robot from falling over by putting out a hand to stop the fall, and it runs on a Raspberry Pi! You can see a promo video from Duke’s below and read more here.

New issue of Hackspace is out – features a Pi Wars interview with Tim Richardson

Issue 9 of Hackspace magazine is out! There’s some great articles in there, from Rachel Wong and her wearable tech to Lorraine Underwood and her fantastic LED cube. Of particular interest to the Raspberry Pi community is a terrific 8-page interview with Tim Richardson who is the Maker-in-Chief at Pi Wars Towers. You can download the issue or buy it from the Hackspace website. It is also available from good retailers.

Photo of Tim Richardson from Hackspace magazine

Make your own low-cost 3D-printed robot controlled by a Raspberry Pi Zero W

Nik Ivanov has released plans for a low-cost, 3D-printable rover called Watney which features cheap, yellow Chinese DC motors inside a pretty lovely 3D-printed chassis and case. It’s all run off a Raspberry Pi Zero W and you can download the code and 3D printer files, and see some detailed assembly instructions, over on GitHub.

RasPiO Night Light – a beta test review of Alex Eames’ latest product

Alex Eames, of RasPiO, has just launched his latest Kickstarter. This campaign is for the RasPiO Night Light. This one is not controlled by a Raspberry Pi, but because of that is cheaper, more stable and is pretty much plug-n-play.

The Night Light is controlled by an Arduino nano clone and is a kit which features:

  • a custom, beautifully-designed PCB (see the pictures below), with eight programmable APA102-compatible hyper-bright RGB LEDs on-board
  • a laser-cut, frosted perspex case with mounting holes
  • a PIR sensor to detect movement
  • a light-dependent resistor to detect light levels
  • a buzzer
  • other components to finish the assembly of the kit

Gallery

In the pictures below you can, first of all, see the RasPiO Night Light circuit board as it comes in the kit with the LEDs pre-soldered and, lastly, you can see the main board fully populated as it will appear after assembly.

Assembly

You will need to put the Night Light together yourself (apart from the surface-mounted components such as the LEDs which are helpfully pre-soldered onto the PCB) so you will need a soldering iron, solder and cutters. This is pretty simple and Alex has promised an instruction guide and assembly video for those who are wary of such kits.

You will also need to program the Arduino clone with either the example sketch or alternatively change the sketch so that it does what you want it to do and then flash it to the board. Alternatively, if you don’t fancy messing around with the Arduino IDE, Alex will do that for you for a small fee (£3) that you can add to your pledge.

Opinion

Alex sent me a semi-assembled and pre-programmed RasPiO Night Light to try out. All I needed to do was to put the case around it and plug it in – ideal for a beta tester!

First impressions were:

  • the PCB is just lovely – lots of custom graphics, everything is labelled clearly and the gold-and-black colour scheme is ideal for night-time use.
  • the Arduino pins are broken out to unpopulated headers, so if you did want to add more sensors and other indicator LEDs, this would be fairly simple with some careful soldering.
  • the case is a couple of perspex plates and fixings – it’s minimal, but it is precisely what you need as a) you want something to diffuse the light coming from the LEDs and b) you want access to the adjustment potentiometers of the PIR sensor just in case you need to change the settings.
  • mounting it on the wall is going to be easy thanks to the four-way screw mounting points on the back of the case.

Putting it together with the case was very simple, and I just followed some instructions Alex sent me to get the fixings in the correct order. Obviously, I didn’t need to program it, but being an Arduino nano clone, this should be very easy from the Arduino IDE.

First of all, I needed to find a power supply for the Night Light. Fortunately, I’d picked up a Poundland USB ‘wall wart’ the previous week and so I used that and the included USB cable. I found I needed to adjust the potentiometers slightly for my lighting conditions as, to start with, the Night Light refused to work. A little tweak with my fingers, however, cured all ills and suddenly I had a working Night Light. As Alex says, the LEDs are bright enough to light your way at night without being so bright that they wake you up!

So, my beta testing began. This involved propping the plugged-in Night Light up against my landing wall and waiting for night to fall. Wouldn’t you know it, I needed to get up in the middle of the night. So, I wandered out onto the landing and, hey presto, the Night Light lit up and showed me the way.

The following day, I wanted to take a look at the example sketch to see if I could figure out the code. Alex let me have the Github link to the repository and I found the sketch. It is, of course, written using Arduino’s C language. Don’t let that put you off! It’s really clear code that is commented on almost every line. I needed to install the FastLED library: a quick Google found this tutorial on the Arduino website. Modifying the code to display a different colour, or different brightness, involves simply changing some values. However, with a little bit of knowledge, you’ll be able to alter the code to your own purposes. Arduino’s variant of C is a good piece of knowledge to have, so consider it a learning experience if you have no experience already!

The Night Light has been doing constant duty on my landing for a few weeks now. I’ve not needed to reboot it or change it at all since I plugged it in again. This is essential for such an appliance. I imagine it pulls very little power, so leaving it on all the time is fine, although switching it on or off at the plug is okay too, thanks to it having no SD card to corrupt! 😉

All in all, I highly commend Alex for a well thought-out and good-looking product.

Why not Pi?

Alex told me something very interesting about his reasoning behind not using a Pi for the project. First of all, an Arduino nano clone is a heck of a lot cheaper than even the original Pi Zero. This makes it affordable for campaign backers. Secondly, when he tried an early version of his carrier PCB with a Pi Zero W, the wireless interference from the W caused the PIR sensor to malfunction – not what you need at night when all you need is a little light on the way to the loo! He also tried a Wemos board, but that had the same problem!

I think he’s made an excellent choice with the Arduino – it is technology that most makers will have experience with, or at least have heard of. Of course, it’s the C language, but this is not beyond most makers. Vitally, it handles power loss as well as any other Arduino – because it uses flash memory, the Arduino just springs back to life without the user worrying about damage or corruption to the file system.

History

Alex previously gave us several Raspberry Pi-related products. These included the brilliantly-conceived ProHAT, the helpful-as-heck Analog Zero, the Duino and the indispensable GPIO Zero ruler and GPIO reference board Portsplus. All these projects have delivered either on-time or ahead of schedule if they’ve been crowdfunded. They’re always high-quality products, and often come with extremely well-written documentation.

How much?

The Super Early Bird price for the kit is £21, rising to £25 once the early bird has finished. For £38 (rising to £45), you can have a custom-etched acrylic plate for the top of the Night Light. For those who just want to show their support, there are lower pledges for just the PCB and for just a new Portsplus.

This may seem expensive for a nightlight. You can pick up simple plug-in ones for a lot less. However, this has a lot more fun attached to it. First of all, it’s a kit and part of the pleasure of owning a kit is to put it together. Secondly, it’s hackable – add components, change the code and personalise the product to do what you want to do with it.

Even though I’ve already got the beta-test version Alex sent me, I will be backing the campaign anyway as a) Alex always delivers and communicates well, and I like a nice campaign to follow and b) I need another one for my Den (the shed).

Find out more and back the project

You can read more and back the project here.

Old rotary phone used as a Raspberry Pi-powered jukebox

James West has taken an old rotary-style telephone and turned it into a Pi-powered jukebox.

To start with, he hooked the dialer up to the Raspberry Pi’s GPIO and then used Dan Aldred’s code to count the pulses generated when the ring was turned. Having done this, he programmed the Pi to play different songs depending on which number had been dialled. He chose songs about phone calls or conversations, starting with Hanging on the Telephone by Blondie when you dial 1. The transfer of the Pi’s audio to the handset was achieved using a Pimoroni Speakerphat, with the volume dialled down (sorry) by simply adding a resistor.

You can see it working below and you can read more here. Take a look at other James West builds by clicking here.

Beating spinal muscular atrophy to fire a gun using a Raspberry Pi

Mike Phillips has spinal muscular atrophy, leaving him only with the control of one eyebrow. However, this hasn’t stopped him creating a list of things to do that would rival most able-bodied “bucket lists”. One of the items on the list was to fire a gun, using nothing but his eyebrow. Bill Binko and the team from ATMakers took this wish and “made it so” by setting up a Glock 17 to be fired with a servo (after they’d cleared the experiment with the relevant authorities, of course!)

The interface with Mike’s eyebrow-controlled system was managed by using a Raspberry Pi Zero, an Adafruit Crickit and a custom circuit board to go between the two. A Pi camera was also used to enable Mike to ‘look down the sights’ and then take the shot.

You can see two videos below about the project and read more about it here.