Just a quick post… ATX to RAMPS board

Hacking an ATX power supply to work with RAMPS is quite dangerous… Power supplies which can give you the Amps are rare.

ATX-RAMPSHere’s a nifty solution. A simple ATX power to RAMPS intermediate board.

Plug in an ATX 24 Pin power connector and two of the 4 pin molex power connectors (preferably from a dual rail supply). Wire them up to the output molex with the bottom pin of the output molex supplying the power for the heated bed.

The 5V and PS-ON pins can be wired to the RAMPS to offer auto-power on (if like me you’re making a bluetoothy remote printer).

Download the Fritzing sketch here.

With this board, next time you blow up an ATX power supply, you don’t have to go through the process of hacking another one… Which increases the chances of electrocution each time…

24Mesh’N Quick Update

Just a quick note to say I’m almost finished with the majority of the 2.4Ghz mesh network classes. These are pretty solid classes at this point with a few minor missing features. I’m hoping to release something really useful really soon.

Goblin Teasmade Upcycle: Part 2

After the first stages were completed, that is, designing the new wiring situation and wiring the internals. The contraption now looks something like this

The wiring pattern was explained in the last post. So the things you see beyond the mentioned pin patterns are the wires for the i2c devices (ghetto pixel, and DS1307 RTC). The RTC is used to keep the time internally, there are some interesting points to consider about the clock face itself and how it will maintain time. More on this later…

Stage 5 – Building a Web UI.

The code for the Web UI can be found here on github. Obviously when you’re serving files from an Arduino via the SD card you want to keep the files as small as possible. After running ImageOptim and minifying the javascript and css It probably all comes in under 150kb. Which isn’t much but is still enough to make the poor Arduino struggle… The HTML code should be runnable in any browser and there’s a neat little clock UI that should make you feel good to watch.

Obviously, you don’t have a teasmade on your network, so unfortunately you won’t be getting a nice cup of tea out of it. Sorry.

Things to note on the Web UI are

  • Moving the cursor over the clock shows the kettle and teapot and their states behind it.
  • Pressing the right hand button makes tea… Well, I’ll mark that as WORKSFORME heh.
  • Pressing the left hand button turns on the light.
  • The freakin’ clock hands animate!!

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3D Printer updates… Why not use aluminium plate?

I’ve ordered a bunch of parts for my 3D printer, essentially to get it up to printing standards without difficulties with the controller etc… So yeah I bought a RAMPS 1.4 and a new arduino mega, and an LCD screen, all new wiring and some fresh PLA on a spool.

I also got to thinking about my warped x-carriage and what could be done about it. My first thoughts were to purchase a new one from 3D Hubs, but having a custom one printed was quite expensive. So instead, I looked at the thing for a while and concluded that I should just cut a replacement from aluminium. This isn’t difficult, aluminium is a very soft metal, it can usually be guillotined or cut with a junior hack saw or jigsaw. I’m opting for the jigsaw. I’m working on a template and once I’m ready to I’ll upload it to thingiverse.

Simply put the aluminium plate x-carriage will be made out of 3mm aluminium and will have 3 or 4 CNC bearings to keep it on the runners. In the middle I’ll cut a 2cm hole and drill holes for the extruder mechanics to fit on. This also made me consider the bed and what can be done with it. So I’m going to look into replacing the bed on the printer with an alu plate probably 4mm with 4 CNC bearings in. That will sit directly underneath the bed heater plate with some foam insulation between to keep the PCB stiff in the middle. I need to get some bending tools to make this right, as I want to have a fan holder and a built-in end stop tag for opto-endstops.

I’m looking for a 700W PC power supply if anyone wants to donate me one? There are a lot of these laying around that people don’t need and I’d rather not create more junk for the giant trash pile if possible to avoid.

Goblin Teasmade Upcycle: Part 1

Here's what the smart home used to look likeDo you remember the Goblin Teasmade? The device was a mechanical and electrical marvel however very likely responsible for many a house fire and probably entirely unsafe by todays standards. The teasmade was the epitome of the must have device for the middle class home of the 1960s, it even featured in the Queen music video for “I Want to Break Free“.

As I’m not shy of a challenge I decided to upcycle a 1963 model into a new fangled Internet of Things device which can make tea over the web.
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3D Printer Fixing….

My much unloved 3D printer has never really worked quite right… I put this down to a bunch of problems firstly my wiring is inadequate in some places (hot bed mostly), my bars have corroded because they didn’t have any kind of rust protection on them, my bearings have corroded in some places and need replacing and my carriage is a bit bent… And my GEN7 board probably isn’t as reliable as a ramps would be.

I have however replaced the seriously inadequate resistor with a cartridge heater. However it’s a good idea to keep it in good condition along with the thermistor because of this: Thermal runaway cartridge heater.

So, instead of buying new bars and essentially starting again. I’ve decided to get some chrome plating equipment and begin chroming the rods to prevent any further rust build up. I’ll replace the bearings too. Then I’ll get to work on repairing some wiring before giving it another test :)

Sunderland airshow today so I don’t think I’ll be rewiring today.

Python DS1307 library for Raspberry Pi

I just spotted an article over on SwitchDoc Labs blog for accessing the HotPi RTC using python which is pretty cool. Please note that the DS1307 on the HotPi is wired directly into the i2c port and is powered with 3.3V so the application notes regarding the pull up resistors do not apply, you should be able to just use the software immediately with your HotPi.

Here’s the example code they have on their website.

import time
import datetime
import SDL_DS1307

ds1307 = SDL_DS1307.SDL_DS1307(1, 0x68)

# Main Loop - sleeps 10 seconds, then reads and prints values of all clocks

while True:

print ""
print "Raspberry Pi=\t" + time.strftime("%Y-%m-%d %H:%M:%S")

print "DS1307=\t\t%s" % ds1307.read_datetime()


It makes me consider importing this into the HotPi-daemon in some way :)

Their github page is here https://github.com/switchdoclabs/RTC_SDL_DS1307

Grab the code and see what you can do!

Experiments with mesh networks

I’ve started building a mesh network in C++, it’s a small library intended for use on Raspberry Pi and Arduino. Currently I want to support one kind of radio, an NRF24L01+ which you can get pretty cheap on ebay.

These radios provide us with a Layer 1 (Physical) of a OSI network but to build a functional mesh network we need a Layer 2 (Data link, addressing) and Layer 3 (Packets), once we have those two layers we need a Layer 4 (Segments, connection management) then onto the final layer, Layer 5 (Data).
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HotPi Update

The stock from the kickstarter has run dry a long time ago and we’re now shipping a slow methodical number of units via the pi hut. We’re running out of green boards now, all new boards are red, and new orders will start to come through that way.

I recently published a new page for the HotPi and the new User Manual. You can get both over on this page.

I’m going to be designing a new small board or two which will fit in to the range of HotPi products. This should take 1-2 months to get back from manufacture and I’ll keep the blog updated along the way.


Turning Photographs into Wireframes, VisualSFM on CentOS6

DL390 G5For the purposes of performing a highly detailed capture of various historical monuments, which are local to me, I purchased a big fat server with oodles of processing capability. The system itself is a 2.83GHz Dual Quad Core Xeon HP Proliant DL390 G5 – not a bad bit of iron. It’s loud, it’s warm but it’s very very quick. Added to that a couple of 1Tb 2.5″ disks and a nVidia 210 with 1Gb of graphics memory. Once you’ve got this kind of hardware you’ve got to put it to good use. First thing for my project was to build up an appropriate workflow for using VisualSFM and Meshlab on the machine. These are tools which perform a “photogrammetric” reconstruction. VisualSFM is difficult to get working, It is dependent on packages which each have their dependencies, it’s also poorly documented generally so I wanted to ensure that my struggle helps out others. CentOS 6 was my OS of choice, I usually use this on a server as it’s pretty low maintenance once it’s configured and support stretches on and on. After a day or so of software builds (btw make -j8 is fantastic) I managed to get it working. I’ll share the binary/source RPMs that I’ve rebuilt and links to the other bits of the entire workflow. Along with a guide on how it is done.
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