It’s been a long haul getting the printer up and running again. I left it with a half finished Z probe for Automatic Bed Levelling, but it never worked quite as intended. I’ve been spending a few hours with it this week and I’ve got it running sweet. To celebrate I printed one of the first bespoke, made to measure parts I’ve ever done. Talk about starting simple, it was a replacement for a 11mm x 20mm dowel that had fallen out of one of Joe’s wooden trucks. I sized the part in blender but despite importing a 1cm cube STL for size reference and setting the scale accordingly, I still had to scale up 1000x in Repiter, the printing software. However, in the end it was really nice to get a part out of the printer that was absolutely fit for purpose and slotted into the hole it was designed to fit. The look on Joe’s face this morning when he saw it was worth the hours of buggering about with stupid Chinese servos and reams of configuration.
I’ve just finished work on the prototype of the moisture sensor. As I type, it’s sitting, powered by batteries, with it’s probes in a hanging basket, sending data to my server in the cloud.
Inside the large tuppaware box there is a 4xAA battery box, from a defunct string of Ikea Christmas lights. This powers the breadboard which still has an FTDI converter plugged into it, along with the ESP8266 ESP-12 in it’s freshly breadboard ready formfactor. The moisture sensor it’s self is a cheapo ebay special and very prone to all sorts of horribleness. Which is why I’ve powered it from a digital pin on the ESP-12, so I can keep it powered on for only as long as I need to.
It’s working, it’s sending data, the scale is wrong, and I don’t like Tupperware, but other than that I’m super happy with it.
Along with building a prototype for the moisture sensor, I needed to get some kind of prototype endpoint up and running for dumping the data into. I had always intended this to be a restful interface, but I didn’t know the quickest way of building one. I’d looked at services such as thingspeak.com/ and data.sparkfun.com but I felt that I should be laying the foundations here for something that I’d be building on later. Ultimately, the server side system will be a Node or Ruby app, but I don’t have time to build that right now, I needed a shortcut.
A quick bit of googling brought me to ArrestDB which was very easy to set up and gave me a fantastically easy endpoint to push data into. It sits on top of PHP and Mysql (just like something else) so I I dropped it onto my existing VPS. As the data grows it will need a server of it’s own, but we arn’t there yet. The only thing about ArrestDB that troubles me is that there is no security out of the box (other than the obvious care you took creating a MySQL user with only the permissions your app needs on the DB it’s going to use), anyone can connect to your endpoint and start spamming/scraping it. I’m planning on adding in a simple secret token to the flow which should stop 90% of naughtiness occurring.
"ts": "2015-05-29 15:48:03",
"ts": "2015-05-29 15:47:52",
"ts": "2015-05-29 15:47:41",
For now, ArrestDB scores 7/10 on my list of cool things I downloaded from github this week.
I needed to prototype the soil moisture sensor on a breadboard, but as we all know, the ESP8266’s in their many different guises aren’t the most breadboard friendly modules you’ll ever come across. The secret here (for me anyway) was some tripad stripboard that I had lying around. I dropped two rows of 8pin headers into the breadboard so they were either side of the central divide, and cut a piece tripad big enough to allow the ESP-12 to sit on it, while the headers sat below. I pushed the tripad onto the top of the headers that were in the breadboard and soldered them on.
I then got some thin copper wire and soldered about 15mm to each contact of the ESP-12. This was fiddly, but didn’t take nearly as long as I’d thought it would. (In the photo you can see that I used a bit of White tape to protect the ESP-12 from the grip of the crocs on my helping hands.) Once soldered, I bent the wires on one side nearly 90º downwards and fanned them out a bit so they would fit through the 2.54mm spacing on the tripad. These were then soldered in place. Next, was the other side, this had to be bent a bit more aggressively, and then fanned out again to get through the holes on the triboard, and when I’d got the module sitting nearly level, I soldered these in too.
I think it looks surprisingly tidy for my work, the module sits above the tripad by about 4mm suspended on rows of copper legs. It works great too. allowing for a rapid breadboard prototype to be built.
Yesterday, two new videos surfaced both shot with drones. It’s really nice to see something interesting being filmed for once, and shows how easy it is to make slow, aerial footage look spectacular. For the Antarctica video the ingredients are: Soft ambient piano based music, trendy sans-serif font (Avenir Next Ultra Light), and slow fades. No added Jump cuts, fast snaps, or crash zooms needed.
The National Geographic film on the Nubian pyramids (which is truly amazing) goes for a much more wholefood approach, honest no-frills commentary. On board audio of the ubiquitous drone insectile buzz, and zero postpro stabilisation.
I just found something really useful in Windows 8 (Shock!) I’ve been worried about the performance of my laptop battery and though I’d see what was out there to check it out. I found that Win8 has a built in report for this which can be run from this command:
powercfg /batteryreport /output %USERPROFILE%\Desktop\battery_report.html
This saves an .HTML file to your desktop with more info on your battery than you thought possible. Good stuff MS.
(We can't actually hide in the woods from machines. Infrared sensors flown in a matrix and processed by algorithm would quickly find us all)
— InfoSec Taylor Swift (@SwiftOnSecurity) November 4, 2014
Do you know why the sky in Neuromancer looked like static? Drones being flown in a high-density 3D matrix creating pixels against the sky.
— InfoSec Taylor Swift (@SwiftOnSecurity) November 4, 2014