Another node type is now available on the Gateway automation interface: a sprinkler controller. This is achievable through a board I designed to be able to control many outputs. I call this board IOShield and it features two 74HC595 serial to parallel shift registers.
The IOShields are daisy chainable and can take 24VAC through a buck regulator. Wireless control is done with a regular Moteino or MoteinoUSB and in a daisy chain only the first board would need the regulator and Moteino.
The most common questions I get about the ESP8266 WiFi Modules are: “Is it possible to control my ESP8266 from anywhere in the world?” and “How can I control my ESP8266 from anywhere?”.
I’m happy to announce today that I have a solution for that problem.
With the new version of Home Automation Server you can add an ESP8266 to your dashboard and control your ESP8266 GPIOs from anywhere in less than 5 minutes!
Happy Monday! Today we’re sharing Episode 2 of “The Fellowship of the Things,” our new video series that follows our team of Creative Engineers as they build connected “internet of things” (IoT) projects in our DIY apartment inside SparkFun. In the inaugural episode, we introduced you to the apartment and showed you our first connected project - The Man Trap.
We know no home is complete without the pitter-patter of quadruped feet, so this time around we got our furry friends involved in a project we’ve (possibly counterintuitively) named “Weight for Treats.”
We built Weight for Treats to demonstrate sensor data streaming and online warehouse sites like data.sparkfun.com, which can be used for remote data logging. The doghouse we built takes weight measurements when a dog enters, and sends it out while rewarding them with a treat.
We’ve also been using load sensors to log and track data from SparkFun’s on-site beehive, and we cover a little bit about how we’ve been monitoring that setup in the video as well.
So there you have it - the latest from the Fellowship. If you have other ideas for IoT projects, let us know, and there will be another episode before you know it!
[Brek] needed to store 64 bits of data from his GPS to serve as a last-known-position function. This memory must be non-volatile, sticking around when the GPS and power are off. Solutions like using a backup battery or employing a $0.25 EEPROM chip were obviously too pedestrian. [Brek] wanted to store his 64 bits in style and that means hand-wired core memory.
OK, we’re pretty sure that the solution came first, and then [Brek] found a fitting problem that could be solved, but you gotta give him props for a project well executed and well documented.
Core memory is basically just a bunch of magnetizable rings on wires. When you pass enough current through a ring it becomes magnetically charged (North or South) depending on the direction of the current. Once magnetized, if you try to re-magnetize the core in the same direction, nothing changes. But if you flip the polarity of the ring, it emits a short electric pulse in the process. Sensing this pulse (and re-writing the bit back to its original state if necessary) buys you one-bit-per-ring of memory that remembers even when the power goes off.
You could string the cores up independently, but that’s a lot of wiring. The trick to making core memory (halfway) reasonable is the fact that a current that’s not quite strong enough to flip the polarity of a ring doesn’t do anything.
Look at the way the cores are wired up in a matrix. If you want to select a single core, you can apply half the current to one of the y-axis wires, for instance, and then another half current to a single x-axis wire. Now the one ring to get enough current to flip state is the core in the cross-hairs; all the other rings in the x or y direction only get half.
What’s amazing to us young(er) whipper-snappers is that this was the dominant form of computer memory from the 1950s to the beginning of the transistor age in the mid-1970s. (Come to think of it, my father’s PDP-8 had core memory cards that I vaguely remember seeing as a kid. The sheer wiring required for 4KB was ridiculous.)
Now back to [Brek]’s project. He’s added some shift registers and H-bridge drivers to handle the logic and current requirements respectively. The sense amplifier lives in a tidy copper cage. The whole build is a sweet testament to over-the-top, bespoke retro engineering. And he gets extra points for the hysteresis logo on the top cover. Go check out his project.
Thanks, [Brek] for all the work and documentation!
Radical Brad over at the 6502.org forum has been working on this cool 7400 logic VGA video game system, Vulcan-74:
Video must be perfectly stable VGA, putting out 256 colors at a resolution of 400×300 using an 8 bit color space divided into RRR-GGG-BB
Video must include full 256 color 400×300 bitmapped screens with a seamless double buffer for high speed animations and high detailed images
The GPU system will include a high speed (20MHz) blitter system capable of dealing with moving variable sized bitmaps from a dedicated 1MB memory bank to the back buffer independent of the 6502 CPU. The entire GPU must be made ONLY of 7400 logic parts
The sound system will be minimum 4 independent digital sound channels, and include its own 1MB independent sample SRAM. Much like the Amiga, the sound system is independent of the CPU, and again all made with 7400 logic parts
The completed system must be capable of impressive games (Amiga quality), not just some simple tile engine. All games will load only from an external EEPROM (cartridge) via onboard 7400 logic based loader. No external processing will be allowed
The CPU will be a 65C02 only. No 65C16, as this is too new for my system! The 6502 will run at 16MHz minimum, using whatever IO decoding tricks I see fit. Bus pirating illegal opcodes, etc. Prelimanry tests have shown stable operation at 20MHz using a ROMless system running from 10ns SRAM
Today is a public holiday here in the UK, and Pi Towers is silent and still. Clive’s in a field “with no network (not even mobile),” he specifies, just in case someone were tempted to try and make him do something anyway. By the time this post appears, I’ll be pursuing a couple of kids around the Cambridge Museum of Technology. Liz and Eben have one-upped everyone by going to Scandinavia. So, in keeping with the leisurely, end-of-summer vibe of today, we thought we’d share a project that’s designed to amuse. We hope it’ll cheer up all those of you unlucky enough to live in places where you don’t automatically get to bunk off on the last Monday in August.
Raspython, a new project aiming to offer tutorials and learning resources for the Raspberry Pi community and for new makers and programmers in particular, brings us instructions for making Joker, a Raspberry Pi joke machine.
A fact that ought to be more widely known is that our own Ben Nuttall is founder and chairperson of the Pyjokes Society. He and co-founders Alex Savio, Borja Ayerdi and Oier Etxaniz have written pyjokes, a Python module offering lovingly curated one-liners for programmers, and it’s from this that Joker gets its material. Ben and friends encourage you to improve their collection by submitting the best programming jokes you know that can be expressed in 140 characters or fewer; you can propose them on GitHub via pyjokes’ proposal issue or via pull request.
Joker’s display is an affordable Adafruit 16×2 LCD Pi plate; this comes as a kit needing assembly, which Adafruit’s detailed instructions walk you through gently. With the LCD assembled and mounted, getting Joker up and running is just a matter of installing the pyjokes module, LCD drivers and Joker script, together with a little bit of other set-up to allow your Raspberry Pi to talk to the LCD.
Everything you need is in the tutorial, and it makes for a really great self-contained project. Give it a whirl!