HacDC Wiki - User contributions [en]

HacDC Spaceblimp

2011-07-22T02:34:33Z

Williamgibb: /* About the HacDC Spaceblimp Project */

[[Category:Ongoing_Projects]]

[[Image: sb5_launch_still.jpg | 300 px]] [[Image: sb3_IMG_6899_small.jpg | 530 px]]

A collection of stuff about HacDC's near space initiatives, including the ''Hackerspaces In Space'' Contest entry (2010).

=Current Status=

Spaceblimp 5 launched July 9, 2011

Details: [http://wiki.hacdc.org/index.php/HacDC_Spaceblimp_5 Spaceblimp-5]

=About the HacDC Spaceblimp Project=
* On Aug 7, 2010, we launched our first balloon: [[HacDC Spaceblimp 1]]. Its epic journey began well enough, but the antenna came loose somewhere around 60,000 ft and we never heard from it again. Until three months later, when a farmer found it in her field, called up a friend (who happened to be an engineer) and it came back home. The pictures are fantastic, but the telemetry data was lost -- it overwrote itself many times over before the batteries finally gave up.

* Following (what we thought was) the loss of Spaceblimp-1, we scrambled and launched [[HacDC Spaceblimp 2]] on Aug 21. It went flawlessly -- fast, light, and with good radio contact the whole way through. It may be the third fastest-ascending amateur radio balloon. We were disqualified from the Hackerspaces in Space competition because we went over budget, but they said we would have come in fourth if not. Sigh. But again, it was an inspiring success.

* [[HacDC Spaceblimp 3]] was successfully launched and retrieved on 13 Nov 2010 with a much more involved payload than previous versions. More cameras, HD video, more radios, an accelerometer, geiger counter, pressure sensor. Weight and price weren't constraints this time.

* [[HacDC Spaceblimp 4]] set the HacDC altitude record, topping out at 103,764 ft! This flight got fantastic video -- make sure to check out the two youtube links.

* Insatiable and unstoppable, the HacDC team puts up [[HacDC Spaceblimp 5]] on July 9, 2011. We bought a yet-bigger balloon to try to get higher, and so: 118,533 ft!

* '''If you want to get involved or learn more or contribute to the program...[http://hacdc.org/mailman/listinfo/spaceblimp Subscribe to the Spaceblimp email list]'''

=Related Links=
* [http://www.flickr.com/groups/spaceblimp/ HacDC Spaceblimp Flickr Group]
* [http://gallery.jbwa.net/SpaceBlimp/SB1/ Images from Spaceblimp 1]
* [http://gallery.jbwa.net/SpaceBlimp/SB3/ Images from Spaceblimp 3]

GPS visualizations of balloon trajectory from the Flickr Group (made with GPS Visualizer http://www.gpsvisualizer.com/):

[http://www.flickr.com/photos/79273063@N00/4946912327/ Google Earth GPS trajectory visualization] and
[http://www.flickr.com/photos/79273063@N00/4947501800/ Google Maps GPS trajectory visualization]

{{Template:Spaceblimp}}
[[Category:Spaceblimp]]

AVR Microcontroller Class 2011

2011-03-29T01:40:54Z

Williamgibb:

Syllabus, course material, homeworks, photos, etc from an Introduction to Microcontrollers with AVR chips class can be found here.

Also see (and contribute to) [[Useful AVR Links]]
Or check out the old version of the course [[AVR Microcontroller Class 2009]]

== Class 0: Introduction and Setup ==

Hello World!

'''Covers''': What the AVRs are, what all the pins do, what they can do for you. A
brief tour of the toolchain, and getting your firmware up and running
on the chip. Reading the datasheets. How to make chips speak digital
to the outside world, pin-by-pin. Just enough C programming fundamentals to
make it work.

'''Slides:''' [[Media:avr2011_class0.pdf]]

'''Lab''': Building the kit and running a test LED flasher.

For assembly instructions and more details on the class kit, see [[Avr2011_kit]].
How to program the class kit, see [[Avr2011 Programming The Kit]].

'''Demo Code''': [[Media: LED_Demo.tgz]]

'''Homework''': More soldering, and Cylon Eyes. Optional extra credit: Simple POV toy (hint, make the timing around 2ms between updates and swing your arms). Super bonus points: Make a neat POV toy.

'''OPC (Other People's Code)''':

[[Media: Pov demo.tar.gz]] An example POV toy. This contains 4 different patterns; two diamonds, a trapezoid and a '''smiley face'''. Also contains examples of using a character array to drive the POV toy, as well as use of constants to determine how the program runs. - Will

'''Resources''':
* ATmega48P Datasheets (get both): [http://www.atmel.com/dyn/resources/prod_documents/8025S.pdf ATmega48P Summary Datasheet] and [http://www.atmel.com/dyn/resources/prod_documents/doc8025.pdf The Long ATmega48P Datasheet]
* Bootloader appnote [http://www.atmel.com/dyn/resources/prod_documents/doc1644.pdf]
* [[Installing AVR Toolchain]]

[[Image:Screenshot-ATmega48-88-168.png | 500px]]

== Class 1: Digital and Serial I/O ==

Interfacing with the real world is the soul of microcontrolling.

'''Covers''': Gathering simple data from the world, and learn how to spit it back out. A serial link with your computer enables all sorts of tricks, and enables the microcontroller version of printf debugging. Some boolean logic comes in handy here. Along the way, we'll learn a bunch about debouncing switches.

'''Slides''': [[Media:avr2011_class1.pdf]]

'''Labs''': More Cylon Eyes, All sorts of button-pressing demos, ASCII-to-binary keymapper, General-purpose serial LED display

'''Demo Code''': [[Media: avr2011_class1_demoCode.tgz]]

'''HW''': Ghetto logic probe and analyzer: read input on PORTC, display values on the LEDs, write out the value of PINC over serial, interpret/log/whatever using your laptop

'''OPC (Other People's Code)''': [[microTweeter]] a silly little program to interface twitter with a microcontroller. It is designed to post quotes from a file when a button is pressed on a microcontroller. This was done as learning experience with python, serial communications and social media integration. -Will G.

'''Resources''':
* More than you ever wanted to know about debouncing: [http://www.ganssle.com/debouncing.htm A Guide to Debouncing]

== Class 2: ADC and PWM: "Analog" I/O ==

'''Covers''': Learn about ways to fake analog data into and out of your microcontroller. We'll learn how to switch logic states fast to emulate an analog output, and how to use the built-in analog-to-digital converters to measure the complex real-world.

'''Slides''': [[Media:avr2011_class2.pdf]]

'''Demo Code''': [[Media: avr2011_class2_demoCode.tgz]]

'''Labs''': Dimming LEDs, light-level meter, ghetto oscilloscope

'''Homework''': Auto-dimming LED or basic light-level data logger

'''Resources''': You'll need to solder up the light sensors: [[http://wiki.hacdc.org/index.php/Avr2011_kit#Adding_the_Light_Sensor_for_Class_2_.28ADC.29 follow these directions]]

== Class 3: Interrupts ==

'''Covers''': Interrupts call subroutines when certain conditions are true. They take a lot of the programming burden off your shoulders, enable the AVR to syncronize to external devices, and are great for super-fast response applications.

'''Slides''': [[Media: avr2011_class3.pdf]]

'''Demo Code''': [[Media: avr2011_externalInterrupt.tgz]], [[Media: avr2011_serialInterrupt.tgz]]

'''Labs''': Bunch of pushbutton interrupt routines, light/dark transition sensor, non-blocking serial I/O

'''Homework''': Response-time-tester Game or "improved" interrupt-driven ghetto oscilloscope

'''Resources''':

== Class 4: Timers and Counters ==

'''Covers''': Timers and counters let you time and count events! Up until now, we've been doing a lot with for loops and delays to count the passing of time. It's much easier and more precise to let the hardware do the timing. When you add interrupts and timers together, the world becomes your oyster!

'''Slide''' [[Media: avr2011_class4.pdf]]

'''Demo Code''' [[Media: avr2011_counterClock.tgz]]
[[Media: avr2011_counterPWM.tgz]]

'''Labs''':

'''Homework''': Response-time-tester Game or tone generator

== Class 5: Flash, EEPROM, I2C, USB, SD Cards, GPS, and Life After AVR Class ==

'''Covers''': First, we'll cover using the internal flash memory and EEPROM for data storage. Then I'll demo how to use other people's code/libraries and tie it in to our packages, interfacing with all sorts of random devices for fun and profit. The final (optional) trick will be turning your classboard into a standalone AVR programmer so that you can program raw chips yourself, and outgrow the bootloader.

'''Labs''':

'''Homework''':

[[Category:Microcontrollers]]
[[Category:Classes]]

Makerbot Operators Log

2011-03-21T00:42:21Z

2011-03-02T05:14:37Z

Williamgibb: Created page with "Category for collecting information related to Microcontrollers"

Category for collecting information related to Microcontrollers

Avr2011 LED Demo.c

2011-03-02T05:14:10Z

Williamgibb:

Cut and paste the following into a file called LED_Demo.c

<pre>
/* Blinker Demo */

#include <avr/io.h> /* Defines pins, ports, etc */
#define F_CPU 8000000UL /* Sets up the chip speed for delay.h */
#include <util/delay.h> /* Functions to waste time */

#define LED PB0 /* Defines pin PB0 for the LED. I
often include a bunch of the circuit
info in the code this way, which
makes porting the code to another
chip easier and reminds you of how to
hook it up. */

void main(void){

DDRB = _BV(LED); /* Data Direction Register B:
writing a one to the bit
enables output. More on the
_BV() macro in the next
lesson. */

while(1){ /* the main loop, from which we never return */

PORTB = _BV(LED); /* Turn on the LED bit/pin in PORTB */
_delay_ms(400); /* wait */

PORTB = 0; /* Turn off everything(!) on PORTB */
_delay_ms(400); /* wait */

}
}

</pre>

[[Category:Microcontrollers]]

2011-02-24T01:42:12Z

Reprap

2010-12-27T01:29:41Z

Williamgibb:

Makerbot machines.xml

2010-12-27T01:29:31Z

Williamgibb:

Makerbot Operators Log

2010-12-20T22:52:39Z

Williamgibb:

==== When you use the Cupcake, please add notes here. Newest at top. ====

* Dec 19, 2010. (Will.) Found makerbot in working condition. Fired up makerbot and extruded some goo for a few minutes, had no problems. Printed a large object, makerbot ran without encountering any problems.

* Dec 17, 2010. (Elliot, Will, Speek.) Finished putting makerbot back together with spring-tensioned extruder head. Elliot probably printer some multicolour items, as evidenced by pink plastic shavings in the workshop.

* Dec 8, 2010. (Xaq and Elliot.) We spent a few hours trying to figure out why the feed wasn't feeding. It would go for a few minutes then stall -- white filament or black filament. Xaq was thinking it was a rotation thing, and we noticed that the drive wheel wants to twist the feedstock around in a circle, putting a twist in it. Elliot noticed a ton of back-pressure from the hot end, and wonders if that's not to blame.

* Dec 3, 2010. (Elliot.) Printed out a [http://www.thingiverse.com/thing:1842 bottle opener] and it worked just perfectly. Noticed that the feed had a kink in it, and clipped and re-fed it. It didn't print sucessfully since. Tried to print the [http://www.thingiverse.com/thing:1046 whistle] a few times with no joy. It would stop feeing a few layers into the print. There's something to do with a twist in the feed? Or it the feed slightly oval-shaped and slipping? Fed the makerbot the white ABS feed, which is slightly thicker, and it printed flawlessly. Hmmm...

* Nov 29, 2010. (Elliot and Xaq.) While Xaq was in the space, we both spent about 2 hours of frustratingly abortive 2-minute prints, attempts at raftlessly printing a [http://www.thingiverse.com/thing:49 coathook]. Shortly after Xaq left, Elliot printed a coathook with a raft and it worked well enough (with babying on the feed at points). Elliot then printed [http://www.thingiverse.com/thing:1912 dino-2s for the brutstruder] without rafts with only one flaw in the first of five prints. I'm at a loss for what changed: it got later at night, and the machine had been in continuous use for longer. I wonder if the bot needs much longer to warm up than we thought? Anyway, before printing something raftless, I would try printing a rafted small object first as a sacrifice to the makerbot gods (or at least to verify that the machine is working) because that seems to be a lot less tweaky.

* Nov 27, 2010. (Elliot.) Printed small odds and ends, just to watch it go. Looks great. The new spool which Dan B and I built seems to work fine, and certainly won't tangle. Moved it to its own (partly mobile) table. I've been working on raftless settings, and it's looking great. Printed a few of the heater-retainer collars for later in case we need them, and tossed them in the reprap box. It's about 5 hours of printing time since the rebuild and it's behaving flawlessly. Will this continue? Knock on wood.

* Nov 26, 2010. (Elliot.) Having broken the hot end of the extruder, I needed to fix it. Took it completely apart and soaked all the parts in acetone, getting all the melted plastic off. I reinstalled things as per the makerbot instructions, with the exception of using teflon tape to (electrically) insulate the barrel from the nichrome wire, because its original sheathing had come off during removal. Noticed that the brass barrel was installed upside-down, so I fixed that. The nozzle seems to be flowing a lot now -- so much that I had to reconfigure skeinforge to deal with the extra plastic. We'll see if it holds up. Printed out a [http://www.thingiverse.com/thing:4036 brutstruder] and the plastic axles for the new feed spool.

* Nov 24, 2010. (Elliot and Will G.) Still having problems with intermittent extruder stoppage. Will and Elliot removed the hot end and cleaned it out. That wasn't the problem. Elliot noticed that the idler wheel was binding, fixed that. Still not the problem, though it has sufficient strength to push through whatever is giving the high back-pressure. Elliot started to re-do the hot end again, and probably messed up the heater in the process. Hopefully it's just a loose wire, but the insulation and heating element may need to be re-worked. Sucks....

* Nov 20, 2010. (Elliot and Tommy) Noticed that gear motor was out of line. Tommy and I added a bearing to it. Extruder still just randomly stops extruding after 15 minutes or so.

* Nov 18, 2010. (Elliot) Printed out some widgets. Extruder head stopped extruding halfway through a print, turned out to be due to ABS bits fouling up the pushing-gear teeth. Also had some troubles with adhesion of the raft to platform.

[[Category:Makerbot]]