Category Electronics

So, the other day a large crate arrived on my doorstep.

Hmm, what could this be?

Yep, I treated myself to a new toy. A 40W CO2 powered lase CNC engraver/cutter (Model K40-III). Now, this isn’t exactly a top of the line model, infact it is probably the cheapest you can get one without going down the DIY route. It is a very cheap device from China, with the most basic of functions. Basically an X/Y axis with a couple of stepper motors, a 40W laser, and a very basic controller board. The main drawback (besides all the instructions being in Chinese) is the fact that it will only work with the rather rubbish software that comes with it, and that will only run on Windows XP. That isn’t going to work for me, especially after finding an old XP laptop and trying the software out. To say that it is buggy and un-userfriendly would be an understatement.

Thankfully, I knew this before purchasing it from eBay. There is a great open hardware project call LaOS, which is designed to replace these cheap and nasty controller boards on these types of lasers. So, armed with a PCB from the project, a bunch of components, lots of pictures of the existing setup, and my trusty multimeter, I am going to set about installing a nice LaOS board. The benefits of this new board is the fact that it adds network capabilities. It becomes effectively a network printer, controllable from a linux machine as a Cups based printer. This way, programs like Inkscape to draw the desired output, and send it to the machine. A much easier way to control it.

An LCD display with local controls is also available as an addon to the main LaOS board. All in all it should turn this cheap basic machine into something fairly usable. It should then be able to compliment my printer for making things, and Joy should also be able to use it for some of her arty stuff.

Testing!

So, first stage was to do a few tests to make sure it had survived the journey and was in a working condition before I break it. The front panel has a handy laser test button to let you fire the laser without having a computer hooked up. Needless to say, after hooking up the water pump to cool the laser, I had a bit of fun burning things! 

Seems to be working ok

And with it hooked up to a computer with the rubbish software

About the best I could do with the software supplied

All seems good, so time to take it apart! Hopefully the next post will have a nice success story of a much improved machine

Unboxing!

Unboxed!

Thats a 40W Laser

Second part is here

I got a nice parcel delivered today. Two nicely build hotends for my new Prusa Reprap. After all the issues with the Huxley, the Prusa has been a total doddle. The last piece I needed for it was a hotend, and after having some issues sourcing some of the components, I had a look on eBay for any pre-built ones. I found one guy shipping some from Poland that looked perfect for what I needed, not only did they have all the molex connectors already done in a way that is compatible with my Sanguinololu board, but he was offering a twin pack with one .5mm and one .25mm nozel. Oh, and a pre hobbed bolt too!

So, with the body built and the electronics tested, all I have to do is figure out how to attach the hotend and I can start building. I’ve already posted a video a few days ago of the body moving nicely, which is further than I ever got with the Huxley. Never know, maybe by this weekend I’ll be able to print something! Just have to finish work first.

Here’s the video of the first test of the electronics.

The replacement electronics for my Reprap Huxley arrived today at long last. I’ve had them plugged in for nearly an hour over dinner, and no flames. Good start!

I think this evening and weekend are going to be devoted to trying to get my printer working. I hope nothing else turns out to be faulty with the kit I bought. I’m already very disappointed with the quality of it overall. If I had a better understanding of the whole Reprap process, I would have gone with just ordering the plastic parts from somewhere and building my own. I’m sure I’ll do a full write up on it at some point.

To recap, I’ve got the frame built with all the stepper motors mounted and the belts in place. So all(?) I have left to do is:

• Calibrate the electronics
• Finish the extruder – Just needs the motor mounting I think, and the tube inserting.
• Finish the hot end – All gunged up, just needs the electronics attaching to the nichrome wire and thermocouple.
• Mount the hot end
• Mount the end stops

Once all that is done, I may actually be able to start testing. The testing is going to be a long process I think, I very much doubt I’ll be printing quality objects from the start. Lots and lots of wasted plastic doing test prints, levelling the base, etc. Still, if I can finish this weekend with an actual printed object I’ll be happy. Roll on 5pm when I finish work!

Since deciding to renew my interest in electronics over the past few months, I’ve tried various websites for supplying components and parts, along with some good sites for learning and ideas. I thought I’d do a quick write up of some of my favourites and put it all in one place.

Firstly, lets start with components. You will always need somewhere to get all your bits from, as well as tools and consumables. Here’s a few sites that I’ve found both handy and reliable. I do like to be able to get everything I need from one place, but I haven’t yet found a one stop shop for everything, but I have managed to narrow it down to just a few that will satisfy most of my needs.

• Bitsbox – This is a great site to get your basic components from. They are cheap, well stocked, and have a nice simple website to use. You won’t find things like Arduinos, or Sparkfun kits, but you will find just about all the basics you could ever need. Components can be ordered in singles, or bulk, and delivery is pretty rapid. I tend to use Bitsbox to stock up on standard things like resistors, capacitors, common chips, and other non specialist components.
• Proto-Pic – This is where you go for the more ‘building block’ style components. Things like Arduino, Sparkfun, sensors boards, breakout boards, etc. Great place with a nice easy to use website. I do find that I need to watch my spending here. It is too easy to keep loading up the basket with fun parts, especially shiny things like LEDs. There is a lot going on now in hobby electronics where you buy pre built component modules and link them up for a project, rather than scratch built circuits. Good communication from the staff here, and will part ship your order if they are having trouble with stock, instead of having you wait.
• Cool Components – Very similar to Proto-Pic. You should be able to find what you want in one of these two stores. I’ve dealt more with Proto-Pic than Cool Components, but more for familiarity than any other reason.
• Jeelabs – This is a slightly odd case, and is a more specialised shop than the rest. I’ve been working a lot with JeeNodes, and this is the place to source them from. Its a one man shop, but he is designer, builder, and shipper. He also provides a lot of information, not only on how to use his products, but also in general electronics knowledge.
• Unmanned Tech – Not exactly in the electronics section, but this is where I get my quadcopter autopilot components from. I just wanted to mention it here because the support that is given is great. Very friendly and actually want to help.

Next, lets look information sites. These are places to go for learning more about electronics, techniques, and news.

• Jeelabs Blog – As mentioned above, Jeelabs provides JeeNodes, along with other modules to go with them. The blog provides a lot of information about how to use their products, how they were designed, and also general information such as circuit design, how to improve your arduino sketches (especially making them low power), and walks you through good ways to measure and bug trace your own circuits. Well worth following.
• EEVBlog – A great, fun blog by a mad aussie. (Are there any other types?!) He has a regular video blog on a fairly wide range of electronics subjects, including reviews on lab equipment, tear downs of new gadgets, and instructions on circuit design. He’s now making a living from this blog after having many years work experience in electronics. Videos are released on a pretty frequent basis and are well worth a watch just for his enthusiasm!
• Instructables – This site is just fantastic. People from all over the world with a passion for making things can upload full build instructions to this site for all to read and reproduce. Its not just electronics here either! Anything that involves making things can be found here, from needle work to metal work! The information is free, but it is worth signing up for a full members account which allows you to view the instructables in a single page, rather than multi-page, and also download it as a PDF. Handy for putting onto an e-reader or similar. Great place to look for ideas for projects, or help on something you’re working on.
• Makezine – Makers are taking over, and this is the place that pretty much summarises the movement.
• Thingiverse – If you have a 3d printer, laser cutter, or cnc mill (or at least access to one), then you can find many actual objects available to download to be produced. The idea being, if you need something, and design it, you can then upload it to this site for anyone else to produce for themselves. An open source object library.

Thats it for the main part. A few honourable mentions go to RepRap for all your 3d printing needs, and also Youtube. There are many many videos there that are well worth a watch.

Okay, its been a little longer than I hoped for for an update, but it has been Christmas so I’m using that as an excuse.

The build of the huxley was going very nicely until I hit a few snags with the kit I’d ordered. Firstly, there are nowhere near enough nuts, bolts and washers provided to complete the kit. I ran out before I’d even finished the frame, let alone mounted the motors, built the extruder, or made the idlers.

Secondly, the belt for the X axis was too short, so I couldn’t fit that.

Thirdly, the electronics actually burst into flames on me whilst testing and configuring the motors. This was before I’d actually done anything bar plug the power supply in. To say I wasn’t impressed doesn’t quite cut it! Oh, and the analogue to digital converter for the hotend was missing.

So, considering I got a kit for hassle free construction of my first printer, I’m not overly enamoured with it. The UK company have put me in touch with the manufacturer to get things sorted, and they have said they will send out the replacement/missing parts from the states, so hopefully things will get sorted, but I could’ve had a nice working 3d printer by Christmas had everything been right in the first place. The instructions on the wiki also leave a lot to be desired, especially the hotend page, which were for a totally different design. Only one photo showed the model I’d got.

In the meantime, whilst waiting for the replacement parts, I’ve done some research into the electronics available for the various reprap machines, and have decided to build my own electronics based on the generation 7 schematics on the wiki. These electronics all fit onto a single sided PCB, so nothing complicated, and seem to be relatively simple. In fact, I bought a pre-made board off eBay, and had most of the other electronics already ‘in stock’ in my cellar. The gen 7 boards also use pluggable stepper motor drivers, which mean that if one does burn out, then you can simply plug another one in, unlike the kit electronics where everything is surface mounted and impossible to replace.

With all this, I’m hoping I can get a chance this weekend to finish off the electronics and get the main body of the printer working. I’ve built the extruder, mounted the motors, and got all the belts on, so all that is left is the calibrate and level it all, and build the hotend. I’m hoping the hotend will be fairly straight forward, but as I’ve no real instructions, just one picture to go off, I’m going to be very careful!

Anyway, here’s some pictures!

Main frame

X Axis

Y Axis

Y Axis in place

X and Z Axis in place

Extruder

In other news, I’ve been rather impressed with how easy Google SketchUp is to use. I’ve been messing around with it to design the parts for me printed quadcopter. For a beginner who just wants to make simple parts to be printed on a reprap, it is perfect. Install the plugin for exporting to STL files, and you can both upload these to thingiverse, and import into most of the 3d printer software that is available for the repraps.

Also, slightly related, I’ve actually had a quadcopter flying with the Arducopter controller. It was only a brief test as I managed to crash it and shatter 3 of the blades. Spare blades only arrived on Christmas eve, so not had a chance to do much more with it. Just waiting for some better weather so I can fly it outdoors. I’ve managed to snag myself and OpenPilot Copter Control board too last week which should be arriving any day. This is a halfway house between a simple KK Multicopter controller, and the full blown ArduPilot Mega. I’ve got the APM telemetry kit coming soon too, so I can take my laptop and get live telemetry from my quadcopter. Unfortunately, my laptop battery has developed a fault, so the only way I’ll be able to do that at the moment is if I can fly it somewhere with a power socket nearby!

So, hopefully next week I’ll be reporting that my printer is done, and will at least have done a couple of nice test prints. I think my first actual things to be printed will be brackets and improvements to the printer tho’.

Two parcels arrived this morning, one a 2.3kg reel of 3mm ABS filament, the other was a surprisingly small box full of plastic and metal. Otherwise known as a RepRap Huxley 3d printer! A little over 3 weeks past the expected delivery date, but at least its here now.

Unfortunately, work got in the way of me doing much, but an hour of my ADSL being broken over dinner meant I could at least open up and check the contents. I must say, it is smaller than I was expecting, but thats a good thing. This should fit nicely on my desk and not take up too much room. The box contains everything you need to build the printer, bar tools of course. This kit is actually an import from the states, sold through a UK company who I assume buy a load of these and then ship them out locally. It did come with a US power cord on the PSU, but for me that isn’t exactly a show stopper! No instructions are included, instead everything you need is online on a wiki, and in numerous videos supplied by other people who have built them and in true open source fashion, contributed back to the project. In this vein, I’m hopefully going to improve the instructions on the wiki a little. I’ve already spotted a few areas that could be improved.

Wonder how long this is going to take me!?

Plastic parts, and metal rods.

Over the past few months I’ve been slowly stocking up on all the equipment needed to properly get back into electronics. As I was gathering things together I discovered Arudinos. These are an easy entry into microcontrollers, much simpler in my opinion to PICs, and cheaper than most other developers kits. The fact that they’re open source and open hardware just seals the case. The standard Arudinos are rather nice to work with, but since messing with them on a few mini projects to teach myself about them, I came across a guy who was selling his own custom design, utilising the arduino bootloader and interface, but in a much smaller form factor and inbuilt wireless communications.

These JeeNodes are about the size of a pendrive, and have an inbuilt RF12B wireless module. Along with the nice hardware design, there are also some easy to use libraries, and a great website to accompany them, with lots of nice tutorials, information, and general geekiness.

So, where does home monitoring come into this? One of the addon boards that Jeelabs sell are little room monitoring nodes that detect temperature, humidity, and light level. Add a PIR and you’ve got a motion sensor too. The guy behind the JeeNodes, Jean-Claude Wippler, has done some great work on power consumption meaning that these room nodes can run off a single AA battery for nearly a year. There are about a dozen or so of these nodes now spread across my house, logging into a database, and I’ve done some basic graphs to display the data.

Now I’d also noticed another project using arduinos to monitor electric consumption that was also based on JeeNodes, and reporting back to a central server to log into a database. This got me thinking, could I combine these, and maybe more. The beauty of open source is the fact you can tweak and edit to your hearts content. The fact that both these projects used JeeNodes, and more importantly, the RF12B library from JeeLabs, means that I only need one receiving station and a few small edits to the nodes.

To the transmissions I added a node type to the beginning of the data. This defined whether the node was a room node, power node, or any other future node types I may define. Most of the rest of the code was left untouched, except to assign a node number to each node. That was the easy bit.

Next I needed a receiving station, and some way to get the data it received into a database. For this I once again turned to the JeeNode. Handily, JeeLabs also sell a nice case for the JeeNode, along with a Ethernet add on. This gives me a very small self contained module that simply needs power, and an ethernet connection. Both the energy monitor project, and the room node project had their own code for a base station, and for getting the data into the database. In the best traditions of open source, I have stolen from both these projects and combined my favourite ideas out of both.

The houseNode sits and listens for any broadcasts from any nodes. It knows about the different types of nodes, and the data structure to be expected for those nodes. When a data packet is received then the node type is stripped out, and the rest of the data put into a structure definition depending on the type. Then a JSON structure is constructed, and sent via HTTP POST to a web server. No acknowledgements of data being received are currently sent, but with future expansions that I have in mind, this will be a requirement.

The web server will receive the POST command, and basically dump this information into a database. From this database, a front end can draw graphs and report on anything you want. The front end is very much still in construction, but can be viewed at http://home.22balmoralroad.net/

Future developments I am considering are a thermostat node, to control our central heating, and RFID entry/exit nodes to log in and out of the house. The RF12B modules have a limit of 32 addresses, two of which are reserved. However, 30 nodes should be enough for most of my ideas! It does have the other benefits of very low power, very simple, and the JeeLabs library even has encryption built in. Below are the Arduino sketches for each of the nodes.

My Cellar, AKA the command center!

I’ve had a fairly productive weekend sorting out my cellar, ready to crack on with some of my projects, although strictly speaking sorting out the cellar was actually on my list of projects. Besides the standard cleaning up of all the mess, including a good hoovering, was the final vanquishment of the cable monster. I know he’ll come back at some point, but I’m hoping that with enough will power from me to actually put things back where they belong, his return will not be for a long time.

Before (Already was beaten down from his full might about 3 months ago!):

Now:

Next on my list of projects down here is the construction of my workbench panel. I want to embed a load of my equipment permanently along the back of the workbench, so for this I knocked up a quick frame that allows me to start mounting some of my tools. So far I have my digital power supply and OpenBench logic sniffer. The digital power supply is one built from a kit available online from Tux Graphics, which is a nice little variable current/voltage power supply, powered by an old laptop PSU, and controlled with an Atmega8a microprocessor. It will also hook up via usb to a computer, but unfortunately a slight design error in the placement of the power switch prevents me from doing this at the moment. The OpenBench logic sniffer is an open source logic analyzer hardware design.

I also want to embed a few other tools into this panel, such as a multimeter, frequency counter, usb hub, signal generator, and just about anything else that is useful and will cram in here.

In other projects, still waiting for me 3d printer to arrive. RepRap Central said to allow 3 weeks for delivery, but so far it has been over 5 weeks. I’m not impressed at all, and if they weren’t the only place I can find in the uk to get the complete kits from I would be going elsewhere. I’m hoping it arrives next week at some point, as I want to document the build process for this web site. On the quadcopter front, I’m beginning to think I’ve got a faulty controller board, or at least a faulty gyro on the board. I’ve ordered another one to give this theory a test, and if the new one works will get it replaced. Not really going to be a waste of money getting another as I’m sure I’ll be building a few. Once I have this first one off the ground, a bigger better one will be in the pipeline with full arducopter control, which includes gps, telemetry, and full autopilot!

So, thats two posts in to weeks. So far so good! 🙂