Tuesday, 30 June 2015

So much soldering

I've soldered my 555 pulse generator and my voltage-modifier onto two small pieces of strip board. Here's a couple of photos of the setup for testing the windings on the 5 cores I'll be using for my first full demo.



(the battery isn't in the case, and the arduino is not plugged in because I had started tidying it away before I thought of taking photos).

This one will be a permanent encoding of the word "timui" which visitors to the stand will be able to read with a probe. The next one will be set up for visitors to encode messages into themselves.

Things are really progressing well! I should be back in TOG tomorrow evening and hopefully I can get another 4 of the voltage-modifiers ready to go. It is getting progressively neater, even if that's not obvious from the photos :)

edited to add: I forgot to mention the 9V power supply problem. I was really looking forward to hooking it up and reducing the number of crocodile clips (and amount of fiddling), but when I tested it I realised it was producing 12V. I guess it was mislabeled; that's probably what broke the device it comes from.

Monday, 29 June 2015

One bit on the Quad Alphanum Display

Things have been proceeding very quickly thanks to Gary and Becky's help. I now have one bit being displayed correctly by my Arduino onto my quad alphanumeric display.

One small glitch became apparent this morning though: the quad display uses 2 of the analog inputs on the Arduino and I wanted to have at least 5 bits in my demo. That's 7 analog pins, but my Arduino Uno only has 6. I considered upgrading to an Aduino Mega, but I've ordered an analog multiplexer instead. Hopefully it'll get here quickly. In the meantime I can add up to 3 more bits before I run out of direct analog connections.

I'll be breaking out the soldering iron tonight. I found a 9V power supply that I'd saved from a broken device, so I'll be replacing the battery in the 555 timer circuit with that, and I have to desolder the socket from the board it's on. Then I have to figure out which pin is which. Then I want to fix the 555 timer circuit and my little voltage shifting circuit onto some stripboard; they've been on plug-board way too long, and it's making me nervous :)

It's so much fun to have a tangle of wires an components on the table in front of me and have a good idea of what's going on :)


Friday, 19 June 2015

One bit down!

I brought my growing collection of gear for the electronics side of my Core Rope Memory project back to TOG on Sunday. @tangentmonger arrived just as I was beginning to despair, and between us we got a working bit of memory! Thanks Becky!


The photo above is the pulse generator circuit (with a 555 timer chip at the centre). We made it with a lot of trial and error, and reference to this page


This photo shows the output of the pulse generator passing through the wire-wrapped toroid core. We were able to detect the induced current in the coil when the pulse generator was active.

I'll be heading back in to TOG, so hopefully there'll be more progress to report soon.

Tuesday, 2 June 2015

My first visit to TOG

I finally made it to TOG last Monday evening to work on my demo of Core Rope Memory. It took me a while to get my bearings, but by the end of the evening I had everything I needed to wire up the pulse generator I need to send pulses through the word-lines (thanks so much for the help Gary!). I'd post a photo, but I haven't tested it yet :)

I'm hopeful that by the end of my next visit I should have a working demo, so that's exciting!