It be that time of year again when all the nut balls come out of hiding! That's right it's NaNoWriMo time again - at the witching hour on this All Hallows Eve a bizar and eclectic ritual will take place - writers will begin typing, scrawling or dictating in ernest in the hope that this year they will make that word goal. That they will be the Nanoer of the finished first draft - I put it to all fellow nanofanatics new and old - lets get writing the madness has begun.
For those of you who are interested I'm 5affy on the forum (that's Saffy but with a five instead of the ess). Or @TheMonsterBlogs on Twitter and the blog I will be blogging upon is Purple Monster - and of course I'll be doing the picture book ideas as well which can be found on Orange Monster.
Jeany is also joining me in this this year! (She has the last two years - first with dictating stuff to me and then last year with her Nano note book in which she stuck stickers, wrote stuff, drew pictures and made collages from mags.)
At the Bristol Hackspace this evening, I powered up a Hall sensor.
The Allegro A1321 takes a 5v supply and outputs 2.5v - plus or minus 5mV per gauss of magnetic field in the sensor.
It turned out that small magnets don't produce many gauss, so I added a 741 op-amp with a gain of about 100 to get more useful output voltage deflection!
Here's the experimental setup:
WIth no nearby magnets, we read about 3v:
But with a very nearby magnet, we get a large deflection, which drops as we get the magnet many cm away, but is still significant:
Clearly we still get significant readings a good distance away, and the nonlinearity isn't too bad; it doesn't max out with the magnet very close but still varies many cm away.
For my next trick I'll make a few of this circuit on some veroboard and hook the outputs up to an AVR with several ADCs that I have lying around, and try comparing the results to measure position (and maybe orientation?) of a magnetic probe...
This is what I have spent my child free morning on :/
Click on the images if you want to see them larger.
They are for a Halloween art exhibit at Center Arts.
Mary loves textures and manipulating things with her hands - she can't put the rings back on the pole yet but she loves tipping them off or lifting them one at a time and playing with the rings.
We also have film night once a week and this is a cute pic of her sitting on the settee joining in
This is a photo from last winter - I just really thought I should share these fantastic icicles!