Hackerhive and the laser cutter

Our Feminist Hackers meetups continue!

Last night a bunch of us met at Noisebridge for a lively, chaotic evening clustered around the laser cutter and breathing its toxic fumes. There were around 10 of us coming in and out of the meeting.

Susan and I worked on fixing up some insulation on the bottom of the door on the Turing classroom earlier in the day so that it will be more soundproof.

We gossiped about SHA-3 and Keccak and looked at the code for Keccak. It is over my head, but was interesting.

We did some stuff on the laser cutter. A bunch of us used it for the first time, and it wasn’t that hard but has some quirks of the software and setting up the machine to cut. I think after I left, Susan and others fixed the exhaust fan on the cutter, till very late into the night. Hurrah!!

laser cutter warning sign

We made a draft version of Amy’s sign for the library aka the biblioteca, and I made stencils for R.A.M.P., (Radical Access Motherfucking Project) Zach (who was orbiting our hive a little bit) made a stencil too that had to do with vegan politics.

I learned how to do “ghost” and “enforce” for my registered nick on IRC. I can’t believe I didn’t know that before! Over 20 years on irc! Well. This explains why sometimes I have lizzard_ annoyingly instead of just plain lizzard in irc.

Jordan, Susan, and CC found new giant fluorescent tube bulbs for the overhead lighting fixture at some point, turned off the power at the electrical box, and got the lights working.

Jordan, CC, and Susan got the HP DesignJet 650C plotter working. It is enormous and can print onto giant map-sized pieces of paper. They printed a photo and then some periodic tables in color. I had to leave before they figured out how to make it print really huge. We need to remember to document how to use it!

Kim gave us these awesome seed-embryo-thing stickers which she puts in places all over and which have several layers of meaning to do with growing and development and creativity. The embryo-thing (as she described it) is at the Fish stage before it has gender or species. A general cheer went up at this idea as we carefully transferred the stickers to our laptops.

Someone else in the space told Lydia to come find us. “I’ve been a feminist hacker for forever, before I even knew there was a such a thing as feminist hackers, which was like, 5 minutes ago!” She asked if it is okay to bring her kid to our meetups. Yes it is as long as you don’t mind them hanging out with us amid the junk heaps and fumes.

I love getting to know people at these casual meetups! I think part of our benefit is that we build trust amongst ourselves and we make a good space for people to step up and try things, or simply to speak up and be heard or put forth their ideas. In short we listen to each other and pay attention. It feels like a nice dynamic and I feel more at home in the space than ever before. We are taking these few hours to focus on each other and ourselves and not pay attention to guys; a minor tweak to behavior that has an awesome beneficial effect. (You would be amazed, maybe, at how hard it is to put into practice.) I hope that other hackerspaces will have woman-centered or feminist meetings, hackdays, or groups and that they’ll be in touch with us.

Cruise control hack on my scooter!

My mobility scooter has a lever which when pressed moves the scooter forward or backward. There aren’t any brakes; I stop by taking my hand off the lever. So in order to keep moving I have to keep pressing this lever. Over time, that hurts my hand and arm. It’s also just tedious! So I wanted to copy what my friend Zach had done and build a switch that would keep the scooter moving. He said it was pretty easy. I took the front casing off my scooter dashboard to see what it looked like in there. Kind of scary, a tangle of wires. If I messed it up, I’d be stuck. I put it back together unwilling to experiment till I talked with someone who knew what they were doing.

scooter wiring

When Zach and I looked at it we took that cover off again and set it aside. The wires were in clusters of three with easily detachable connectors, labelled CN1, CN2, CN3, and so on. CN3’s cluster of wires went to the keyhole, which I could see is very simple. In fact I would bet I could stick an audio jack or some other piece of round metal into the hole and start the scooter. CN2 went to the potentiometer that sits between the levers for forward and back. In other words that lever moves a precision screw that goes into the potentiometer to change the resistance going from the battery to the motor. CN1 went to the forward and reverse lever, and that’s where we wanted to put my switch. We labelled some of the connectors with a Sharpie.

power supply wires

The existing potentiometer was 5k Ohms (it said this on the bottom of the part.) There were three wires going to it; white, yellow, and blue. Yellow went to the forward lever. Blue went to the reverse lever. White was the wire they had in common. Between the white and yellow wire we measured 800 ohms. Between White and blue we measured 4K8 ohms. We would need to duplicate that with the new switch.

IMG_1705

Rummaging around in the hack shelves and bins and tiny drawers in Noisebridge we found two potentiometers with tiny screws that Zach pointed out were very finely adjustable. Precision trimmable potentiometers or trim pots. We ended up using one for the 4K8 and one for the 800 side of our switch.

Here are the tiny drawers and bins we looked through! Imposing, aren’t they?

IMG_1714

And the Pile O’ Junk that overflows from the hack shelves:

IMG_1715

We found several switches, none ideal, and none that looked easily mountable on my scooter’s dashboard. Jake, who is great at electronics stuff and builds robots, immediately found us the right thing, a single throw double pole switch. The switch looks like a little bug with 6 legs — the connectors we soldered wires to — and the flippable part of the switch sticking up from its back. Here it is all wired up, before the hot glue went on.

new switch with potentiometers

We replaced one of the duplicate blue wires with white. (Which I found by rummaging in the hack shelves and bins.)

We realized at some point that the resistance didn’t match up perfectly because we had measured it all while the trimpots and switch was unmounted from the wires but we needed to measure and adjust the trimpot screws while it was connected.

Before we hot glued and mounted everything we put a 2×4 under the center of the scooter to prop it up for testing – so that the wheels could spin without the scooter going anywhere. It worked great when we flipped the switch! Very exciting!

We then dabbed hot glue over the switch and some of the other connections with a glue gun. The glue is kind of rubbery and would peel away easily. It should stop the solder from jolting loose, though.

When we went to mount the switch, we realized it stuck out further back than we had room for in the plastic casing. But it would fit really well in the area for the keyhole mechanism, which was shorter. We ended up drilling a new hole for the key hardware on the lower right of the dashboard, and enlarging the former key area to fit the switch. This took a little bit of adjusting and re-drilling with the dremel while we held the front of the plastic case in place. It was very useful to have four hands. My extremely bright LED flashlight came in handy at this stage.

scooter hacking

Along the way we also replaced and added some washers to hold everything in securely. It was great to have access to all the tiny bits of hardware that Noisebridge has free for the hacking and to all the tools in the shop and electronics lab.

equipment

Thanks so much to Zach for the awesome tutorial on potentiometers and resistance in circuits, and for the hacking help! You can see part of his super slick dashboard here, with cruise control switch, usb port, and other useful charging ports as well as a cute Totoro keychain.

totoro keychain

By installing “cruise control” I basically bypassed a crucial safety mechanism of my scooter. I am trying, each time I flip that switch, to repeat to myself over and over, TO STOP, FLIP THE SWITCH. Three times now in the past few days I have forgotten it is on, pressed the lever automatically with my right hand while cruising; then taken my hand off the forward lever only to be unpleasantly surprised that I don’t stop. (Until I crash into things.) On day 1 I was super careful. On day 2 I was lifting up my backpack while stopped, and the backpack strap caught on the switch. I went barrelling forward to crash into Noisebridge’s media cart and a lot of chairs. Everyone laughed. NOT GOOD. Luckily, only one thumb and my dignity were wounded. Day 3, I had my hand on the forward lever and was stopping on the sidewalk. Except I didn’t stop! I was about to hit both a curb and a knot of pedestrians and all I could do was crash myself into a pole. That worked and I yanked out the key and flipped the switch in a giant panic. So, after that I did a lot more deliberate practice with a “the switch is on” mantra. Any time I am near people, or an intersection, I go back to manual control.

I also plan to build a little shield for the switch from Sugru to prevent accidentally flipping it. It needs labelling as well; when I took my scooter on the airplane yesterday I spent some time explaining DO NOT USE THE SWITCH to the airline cargo laoders at the gate until they were so scared of my “TURBO MODE” that they gave me back the key and carried the scooter onto the plane.

scooter hacking

Next I want to move the keyhole to a spot on top of the dashboard instead of under it, and stick some LEDs and an arduino in there with its usb port sticking out for programming, and some sort of complicated dial so I can make different things happen with blinky lights on the front of the scooter….

Connecting to a Pebble

I came into this room with a jillion people soldering and just finishing their Arduino pebble thingies and some madman crouched by my wheelchair to explain how to mindmeld with it. After a bunch of fiddling and more kibbitzing by a guy named Garth we got this other one working. I am incoherent! Because jetlag, and I’m in New Zealand at day something of linux.conf.au.

Pebble!

Here’s how to do it! On a mac! Incoherently! And not quite like this, which is full of lies.

download arduino software
download drivers

You will have to restart your Mac.

download source of Aiko from github. (You do not need to go figure out github right now, just click on “download source”)

move that into ~/Documents/Arduino and unzip it.

It needs to be like this:

docs/ nursery/
aiko_gateway/ examples/ pebble/
aiko_node/ libraries/ tests/

And in:

~/Documents/Arduino/libraries:

Aiko/ PString/ pebble_relays/
NewSoftSerial/ PString2.zip pebble_relays_aiko/
NewSoftSerial10c.zip pebble/ pebble_temperature/
OneWire/ pebble_display/
OneWire.zip pebble_ldr/

And thusly:

~/Documents/Arduino/libraries/Aiko:

AikoCallback.h* AikoDeviceSPIBus.h* AikoSExpression.h*
AikoDeviceMCP320x.cpp* AikoEvents.cpp* AikoTiming.cpp*
AikoDeviceMCP320x.h* AikoEvents.h* AikoTiming.h*
AikoDeviceSPIBus.cpp* AikoSExpression.cpp* Makefile*

You will be missing a bunch those files and the might not be in the right place. So move them around!

Download and unzip into ~Documents/Arduino/libraries:

http://www.pjrc.com/teensy/arduino_libraries/OneWire.zip

http://arduiniana.org/NewSoftSerial/NewSoftSerial10c.zip

http://arduiniana.org/PString/PString2.zip

Then plug in your Pebble! Yay!

Open Arduino application which you downloaaded earlier.

Select the Serial Port from the Tools menu.

Go to File— Sketchbook — aiko_node

Click Verify in the button toolbar

It should compile

Click the upload button in the toolbar

It turns on! yay!

Make sure to select the serial port in “Tools”.
Click the Serial monitor button in the toolbar. It pops up another window.

select 38400 baud in the dropdown menu

Your Pebble should talk to you now!

thusly:

(node pebble_1 ? (temperature 27.87 C))
(node pebble_1 ? )
(node pebble_1 ? (light_lux 854 lux))
(node pebble_1 ? )
(node pebble_1 ? (light_lux 854 lux))
(node pebble_1 ? (temperature 27.87 C))
(node pebble_1 ? )
(node pebble_1 ? (light_lux 855 lux))
(node pebble_1 ? )

Tell it this:

(relay on);
(relay off);
(relay2 on);
(reset_clock);

You have now Impressed the Pebble. Name it something like R’duinoth. Huzzah!

aiko says hi!