Taking a break from the hanging v-plotter we decided to work on a project that has been discussed for a long while now… The RGB Wireless Pixel.
The idea is these are self contained full colour lights that can be placed anywhere within radio range and controlled from a master. That is, we command the lights all together or individually to change colour or brightness. With that we can create a pop-up light show that could potentially be synced to music or react to passers by. It may even be possible to put them into the windows of a large building and create a massive display… all without wires!
Prototype Wireless RGB Pixels.
We currently have a working prototype based on an ATtiny85 microcontroller, an NRF24L01+ radio module that you can find on ebay for ~£1 each, a WS-2811/2812 programmable LED and some extra passive components. The circuit diagram is available on github and there are more details on our wiki.
We are calling this version 1. The idea is to get people to design their own version of the hardware for this and get PCBs (Printed Circuit Boards) manufactured. To that end we have been running kicad tutorials (kicad is an open source PCB design program) which can be supplemented with the excellent ‘Getting to Blinky‘ youtube tutorials by ‘Contextual Electronics’. Check out our meetups page for details of what we will be doing at future meetings.
Example Wireless RGB Pixel PCB deisgn with KiCad to fit inside a ping pong ball.
When everyones PCBs are deisgned and manufactured we will then assemble, program and test them and eventually, design enclosures and at some point, if everything works, put on a few light shows somewhere!
Right now the software for v1 is pretty basic and more or less a proof of concept. I hope the software will improve as people build their own Wireless RGB Pixels and start programming them! The PoC code is also on github.
Future plans for the project are already being discussed for v2 which will allow the use of sensors in each Wireless RGB Pixel as well as an upgraded micro-controller to allow for these and other features.
Last Wednesday I ran a small ‘Messy Workshop’, where I introduced several students to the processes of moulding and casting. I only had a short amount of time – around 3 hours. Within this I had to squeeze quite a bit in, so I put on my best motor mouth for the occasion!
I brainstormed what I could include, and got some guidance from the tech in the casting room – I’ll create some basic moulds using the vac former, a silicone mould of the same shape in order to do a comparison of the two processes, and a couple of different resin types; polyester (clear cast in this case) and Polyurethane (Fast cast).
After half an hour of me waffling on about the contents of each canister, types of facilities available, and associated H&S we created some basic alginate moulds and created a plaster cast of our hands / fingers.
This was pretty decent and took us to around 11am, when we took a short break – this allowed for us to give the plaster some time to cure. We were all rather hasty in our de-moulding, and lost a few fingers, most people thought this was the most distressing thing they had ever seen, whilst others found the whole thing rather hilarious!
Typical art college fayre!
After all that, we continued on to the resin room where we created the reproductions using the vac form moulds. I prepared several, but gave the option for students to create their own if they wanted to make more than one. I also showed the silicone mould off and we poured that one as well. Over the remaining hour, resin was mixed and moulds were poured.
Well, onto one of the real reason I made this a forum post, was to show off some nifty mould making processes I had a go at. Not only is the nature of these mid week workshops a way to get some cool stuff (mostly hard skills) introduced to students, but is also a way for me to indulge my nerd and try and create / explore new ways of doing the stuff we do already, which can all be summed up as making.
Tuesday was spent mostly drafting in Rhino 3D some nifty tile pieces, the kind of thing we might look at 3D printing one offs, and then going off to reproduces using a variety of casting mediums. (or maybe in the future, we will simply 3d print the lot?), anyway – I made a bunch of tiles.
a typical process would be to create a plastic / wooden / Lego box to place them in to enable us to pour silicone over.
Well, now we’re in CAD and can 3D print the form, why not add a mould box into the mix, print it all out, and pour strait away.
The next thing I went on to illustrate was the process of creating a shape from a two part mould.
The parts for a two piece mould
All the components we went on to make on the Wednesday were simple one piece moulds, with an open back – this enabled us to quickly make some shapes. I created both side A and side B, in Rhino, as if they were made from silicone. The components also included the pour hole and the bleed lines already in place. This is something that you would usually create by submerging the parts 50% on clay and sculpting out the pour and bleed lines.
The next cool thing you add are the ball bearings / marbles, as these create locator pins for both side A and B, ensuring that you don’t miss align the mould and create a miss cast.
In the real world, that’s a days work (sort of ) and is also rather messy, you have to take precautions that you don’t get clay all over your original work. Once you have one side in silicone, you dismantle everything, take it all out – and then re construct the box; this time with the silicone and the part in the bottom, and now you can pour a new batch of silicone on the top (silicone wont stick to silicone) and your on your way to having a two piece mould. Sounds tricky? It is until you do it yourself!
Well – that will all take 2 days what with the cure time, if I’m lucky – and I only have 3 hours. I do have the benefit at this point to a couple of hours to prep for the session however. I think to myself, what if I were to take the workflow of creating the walls for my simple shape and turning it into its own mould box, and creating the mould box for side A and side B of a two piece mould?! Well – here goes. Mouldception.
This is what the mould will look like, rendered blue to represent the silicone material! note the pour holes, bleeder lines and the positive and negative locators.
Everything went as planned! I created the mould boxes for side A and side B, poured in the silicone, and 12 hrs later, had the silicone in my hands.
The silicone parts visualised next to their respective mould boxes.
A quick pour of the parts and we can see how things turned out. the pour hole could have done with being a little larger – perhaps we can use a syringe to force in the material as the working time is around 1 or 2 minuets.
The two parts of the mould taped up and ready to pour
The bleed holes worked really well…. except for perhaps my positioning of them , I was still left with a hole in the first reproduction.
I was able to position the two together, make the pour, and 15 / 20 mins later I got the parts out. The striking thing here was how much they resembled the 3d printed parts!
The parts that I printed were done so on the ‘fast print’ setting so contain all the features of a fast 3d print – its really amazing how much detail is carried through the mould / casting process – and how many comments we got thinking the resin part was made by a 3d printer, as it had a similar weight, finish, and surface quality.
I’ll return back with some HQ images of the printed + resin parts later, so into the process I guess I forgot to document the later (more interesting?) steps!
Collection of moulds, in both PLA and silicone.
Plaster cast finger mountain
The two part moulds.
The principle is that you cannot cast material that goes hard (plaster / resin) into a rigid mould. So here you can see we played around and injected silicone into the PLA moulds.
In the silicone moulds of the same shape, you can see we have poured / cast the resin. the reproduction (minus the air bubble) is great! All details captured.
The two types of mould for the larger tile piece. The ‘Vacform’ moulds and the silicone mould. The silicone moulds (condition cure) are only good for the Polyurethane resins (fast casts) and the vac forms for the polyester resin (clear cast).
Clear cast with pigments – and loosely mixed inside the vac form!
To say it was rather a last minute thing – the turn out was rather good! Despite Rob having man flu and Mark being on holiday, somehow, we managed to get stuff to work! No doubt due to the hard work of clever chaps Neil, Graham and new guys Brian and Dan. That left the rest of us wondering what the heck was going on… But by the end of the session, us newbs had some LEDs blinking, using libraries and even some hand written code!
We took over the Interior Architecture studio this time round, as the Old School house was pre booked, and I no longer have the workshop key. We managed to stay there till 10:45! General consensus was that the group enjoyed the space – having desks to work on and chairs that fit under them. We also had a TV and some banging tunes, when the connection wasn’t cutting out that is!
So, the brief was… lets see what these guys can do. Half of us never having used the libraries or LEDs before – lead to some interesting discoveries. We had an array of products to play with, all based around 2812 SMD LEDs. Some in strips, some loose, some on breakout boards (much easier to handle!) and some 2D arrays. By the end of the night, most were responding to something, either the library samples, some changing colour based on the values of a distance sensor, and some scrolling through a smiley face on the array.
The solder station set up – some hadn’t soldered before, so we were shorting out breakout boards left right and center! We did a good job of getting this fixed and tidied though.
Not addressable, but David’s approach worked anyway! Press the button and the blue LED turns off, and the red LEDs blink – a couple of days in with the Arduino tutorials.
Neil came along with this setup and running – a set of 3 AdaFruit NeoPixels on PCB, looks like the way to go for these things I reckon. I believe these were scrolling through the Fast LED library.
Neil and Brian then went on to getting it to respond to sound using a sound sensor – didn’t work overly well, maybe it was damaged?
Over all it was a good session, most people got something out of it. Certainly an appreciation for the complexity that is Addressable LEDs!
On the 24th Sept 2015, we met for the first time at the Old School House in Boscombe. I brought along my Polargraph and did a short ‘Show and tell’ on connecting and setting up the software and hardware, image calibration and the various plotting options (at least that’s how it went in my head, I was probably rambling and jumping from topic to topic without explaining anything properly 🙂
We plotted Donald Duck and some vector shapes on the night.
Some of my previous Polargraph plots hastily hung around the room.
Back in June we organised a day learning to hit hot metal with hammers. These are photos from the day.
I am the God of Hell Fire, and I bring you…
White light, white heat
If I had a hammer
Anyway you want me
It’s the working, the working, just the working life
Hot in the city tonight
It’s Hammer time
I need a hammer – a hammer – a hammer – a hammer To hammer them down!
Workin’ on the chain gang All day long they’re sayin’
Metal Guru is it you
A blacksmith courted me, nine months and better
Come on baby, let’s do the twist
The hammer and the anvil
Ying tong diddle I po
Im jumpin jack flash, Its a gas! gas! gas!
I like to think everyone had a good day, learnt some new skills and went away with a few items forged in the depths of Mount Doom, or Kingstone Maurward college to give it it’s full name. Thanks very much to our Master Blacksmith, Brian Hill, who, once he was over the shock of having a full workshop to deal with proved to be an excellent tutor for the day, he even provided biscuits.
The last session we put together was the cardboard modelling sesh, our first workshop in quite some time!
I have run the workshop a couple of time with our undergrads at the AUB, and serves as a good session, introducing the user to several key concepts of model making and concept modelling.
The goal for us was quite similar, introduce the concept of why we make models of our designs, when we would make models, and to what quality finish we might choose. Ours was dictated by the material we chose, which was a recycled grey board – its a very tough and condensed board, so had its own set of challenges associated with it.
One thing that everyone found out about the material was just how hard it is to cut! We went through lots of Stanley blades in the process, always ensuring we had a sharp edge. Safe use of the equipment was paramount – so getting used to keeping fingers in the groove of the safety rules, and correct disposal of blades. We even got the box of plasters out – fortunately we didn’t need to use it!
For those a little young to be wielding blades, a pre cut shack was offered and proved a good process to enable precise construction methods.
I use this shack for a range of introductory sessions – one of which is Rhino 3D, and getting the model built ready to use on the laser cutter. I prepared a ‘heres one I made earlier’ and gave a brief overview of using the laser cutter, and we discussed when the laser becomes an appropriate tool, in contrast to making the model by hand.
The first Hebocon build night was fun and some people spent more than an hour putting together their crap robots! Details of the Hebocon battle when we get them.
You still have time to build your own crap robot and join us in battle!
The ‘rules’ (I use the term loosely) we are going by can be found here (pdf).
Basically your robot must be less than 50x50cm and less than 1kg in weight. Technologically advanced robots (i.e. sensors and control logic) will attract penalties. Remember – keep it stupid!
Hebocon – build night
Thursday, Mar 26, 2015, 7:00 PM
Bournemouth Arts University BH12 5BB Bournemouth, GB
8 Makers Went
Hebocon aka Crap RobotsThis is robot wars with a twist, it requires no technical skill, just enthusiasm and a sense of humour. You can enter this with a £2 toy purchased in a charity shop, it doesn’t even have to be battery powered. The goal is simply to take part, trying too hard to win may be considered unsporting.You will get a better idea of…
This is robot wars with a twist, it requires no technical skill, just enthusiasm and a sense of humour. You can enter this with a £2 toy purchased in a charity shop, it doesn’t even have to be battery powered. The goal is simply to take part, trying too hard to win may be considered unsporting.
You will get a better idea of what is expected from this video clip:
Hebocon’s “Hebo” comes from the Japanese “Heboi” (ヘボい) meaning clumsy.
The aim of Hebocon is to enjoy the “Heboi” condition. The meaning of “heboi” in Japanese means poorly made or having a poor self-image, and there are two meanings to Hebocon’s “heboi”.
We are offering a build night where you can get some inspiration for your creation and hopefully make a good start on building your robot. Bring a toy, something you’ve made your self or just a box of bits. Battery power is optional. We will bring glue, sticky tape and tools.
Despite the refurbishment work taking place at Makers Inc, the Google Cardboard workshop was a lot of fun and probably one we will run again at some point.
Everyone got their Cardboard assembled and nearly all the phones worked. We only have two handsets that didn’t support all the required features. They were a Moto G and a Galaxy mini. The Moto G doesn’t have an accelerometer and so can’t do head tracking and the Galaxy Mini wasn’t powerful enough to render the display.
We also had one phone that suffered from double vision – that was an HTC but I can’t remember the model. Interestingly I had seen this double vision issue with my own Nexus 4 while running the Chrome VR experiments but is fine with the Google Cardboard app.
While watching the Google IO video on Google Cardboard, they mentioned that you can change the interpupillary distance by programming that information into the NFC tag that is used to launch the Cardboard app then putting your phone into Cardboard. This might fix the double vision issue. I will look into how that is done as i’d like to see the Chrome VR experiments working properly on my Nexus 4.