I finally got time to hack together the prototype for the class project for my class this weekend. We’re going to be using the RaspberryPi to connect to Plivo and make phone calls, nominally to our Mom’s. I thought one button was boring so our call Mom Button class will actually have 4 buttons suggested as:

* Call Mom
* Call Dad
* Text Mom “I love you”
* Mother’s day special

For more details or to sign up see Meetup.

So, while I read through the book, I kept two questions in mind:
1) Will this fill gaps of my own self-taught electronics knowledge?
2) When someone asks me for help, can I just hand them this book? Seriously people, leave me alone.

Disclosure: The publisher, O’Reilly, provided a free review copy of the Encyclopedia through the MakerBar’s status. I love biting the hand that feeds me and would have loved to test O’Reilly’s moral integrity by slamming their book… except it’s actually really damn helpful!

What it is: A Who’s Who of circuit thingies with a wide range of high-level information on each part. It covers LCR, switches, electromechanical, diodes, voltage converters, and transistors. For each component, sections explain What It Does, How It Works, Variants, Values, How to Use It, and What Can Go Wrong. Sample circuits, graphs, diagrams, and color pictures explain concepts, and technical terms are highlighted and defined inline.

What it isn’t: A tutorial, introduction, or reference. The Encyclopedia explains what each component can do, but offers very little help to actually do it. The information is tightly packed and assumes you know basic circuit concepts, making it unsuitable for new hackers. Many uses and critical formulae of each component are missing, making it an inconsistent help. The book is not organized for quick reference.

Who should read it: Hardware hackers who design their own projects, and engineering students. The Encyclopedia is at its best when you’re browsing. To a rookie circuit builder, this is the absolute best way to “see what’s out there”. A self-taught hacker will find that this book fills in many little gaps that circumstance just hasn’t taught yet. I wish I had this book while taking my sophomore circuits class – the professors teach the equations about each component but never explain what it actually does!

Who shouldn’t bother: Brand-new hackers or veterans. While the book is clearly written, it’s still useless without some basic electronics literacy. A beginning hacker would only get confused – it doesn’t explain how to use the components or what makes various properties significant. An expert has nothing to gain from this book, as the information is very high-level, everyday usage.

What’s good: Great illustrations, clear writing, and a to-the-point style get to the important information right away. This is all killer, no filler – here is a component, here’s how it works, here are some different versions, here’s what you can do with it, here’s how to blow it up, next component. You can open the book to any place and learn something new.

What’s bad: Poor organization and layout make it virtually impossible to find the exact fact you’re looking for. The component names on the headers are near the book’s spine, so you can’t flip through the book to land on your target component. Important info is buried in odd places. The book has a bad habit of putting a figure on one page and the explanation on another. Components and subassemblies are shown in diagrams but model numbers are not provided. Terms usually found in datasheets, like h_fe and input impedance, are mentioned in the text but not included in the index.

Buy, borrow, or bootleg? Buy, if you find yourself making many of your own electronics projects. You’ll cut out hundreds of hours of aimless Googling. You’ll fill in gaps in your knowledge and have a wider array of ideas to choose between when you’re at the breadboard. You’ll also be forewarned about the tricky issues that can destroy components, saving you debugging time and money.

Does it solve my problem? I now have more information to call on when designing and troubleshooting my many circuits. However, I don’t feel comfortable giving this book to a brand-new hacker in need of immediate help. Looks like I’m stuck being the resident know-it-all after all.

The Zack Freedman Objectively Arbitrary Rating: Four out of five TI boost/buck converters, which totally should have been named in the text, because I want one.

The BakerBar is the Garden State’s first bakerspace, a communal kitchen for casual cooks and aspiring pâtissiers to learn and experiment. Through the efforts of Bake Magazine and Baker Faire, as well as startups like Adafruitcake and Sparkdough, the Baker Movement has rapidly become the toast of the media. The BakerBar will bring the magic of DIY pastry to Hoboken, the city of Carlo’s and cannoli, in an accessible and fun community center.

To house the new organization, BakerBar founders have leased a 1,100-square-foot extension to the historic Neumann Leathers building on Observer Highway. Over the next three weeks, volunteers will work around the clock, tearing up rotted beams, restoring the parquetry floor, and installing industrial kitchen equipment donated by Hoboken businesses. The end result will feature two large work tables, a lounge/dining room, a shop stocked with dough hooks, rolling pins, and mixing bowls, and dry ingredient storage.

Just $100 per month gains a BakerBar member 24/7 access to the kitchen, free classes, and a dedicated oven rack. Nonmembers are free to participate in two free open events each week – Frosting Wednesday, where participants can purchase custom BakerBar recipe kits; and Friday Bake Night, where our equipment is open for free use. In addition, members share their skills in exciting classes, including:

• Learn Ganache the Hard Way – Follow the challenging online glazing course with help from BakerBar members. This popular teach-yourself-icing class doesn’t cut corners; you need to chop your own chocolate and regulate your own temperature, no pre-made ingredients allowed!
• Phyllo for Organic Life-Forms – Get a hands-on crash course with the wildly popular dough in our introductory class! Phyllo is the base for countless pastry projects like cookies, pies, and even Beef Wellington. Even if you’ve never set an oven or defrosted a dough, you’ll be baking in no time. Toppings kit included!
• Raspberry Pie Hack Day – Our favorite British import, Raspberry Pie is sweeping the nation! Learn how you can modify and use your Raspberry Pie. Install a new filling, experiment with alternative toppings, and decorate a custom box to bring home.

The BakerBar is set to open on April 20th due to massive community response. “My friends are all talking about ‘getting baked’ on 4/20,” said MakerBar founder Zack Freedman. “I’ve never seen them cook before, so they must be ashamed to practice it openly. That’s why I got behind the BakerBar project – everyone should feel comfortable doing their hobby, and have access to the skills and tools they need.”

The MakerBar is Hoboken’s hackerspace, a place for hackers of New Jersey and New York to gather and build incredible things. Members share skills and practice soldering, electronics, handicrafts, 3D printing, woodworking, rocketry, robotics, and more. A 501(c)3-pending nonprofit, the MakerBar’s 16 members will celebrate the organization’s first anniversary next month.

Our Gaming Technology class uses Minecraft to teach basic networking, Java, and interpersonal skills… we’re hosting these in 2 locations- MakerBar and the Hopes Computer Lab @ Jacob Rue school in Hoboken.

Come join us as we attach Raspberry Pi to Minecraft in the coming months.

Tell your Minecraft-loving friends !

Ou

mypov.c:81:9: error: attempt to use poisoned "SIG_TIMER1_COMPA"
mypov.c: In function ‘SIG_TIMER1_COMPA’:
mypov.c:81:1: warning: ‘SIG_TIMER1_COMPA’ appears to be a misspelled signal handler [enabled by default]
make: *** [mypov.o] Error 1

We fix it by modifying the Makefile in the minipovfirmware directory from:

CFLAGS = -g -O$(OPT) \
-funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums \
-Wall -Wstrict-prototypes \
-DF_CPU=$(F_CPU) \
-Wa,-adhlns=$(<:.c=.lst) \
$(patsubst %,-I%,$(EXTRAINCDIRS)) \
-mmcu=$(MCU)

to:

CFLAGS = -g -O$(OPT) \
-funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums \
-Wall -Wstrict-prototypes \
-DF_CPU=$(F_CPU) \
-Wa,-adhlns=$(<:.c=.lst) \
$(patsubst %,-I%,$(EXTRAINCDIRS)) \
-mmcu=$(MCU) \
-D__AVR_LIBC_DEPRECATED_ENABLE__

Control Something

Do you need to exercise some control over the physical world, but don’t want to leave your computer? Well then, take a minute to set the color of my desk on a day of your choosing at http://colormydesk.com/

Yes, I backlit my desk and connected the lights to a server that anyone can control.

THE BASICS

• I used a Raspberry Pi, a small Linux server.
• I built a circuit that allows me to power RGB lights with 12-volt power without frying the Raspberry Pi.
• I developed the website, http://colormydesk.com/, on CakePHP that handles requests from the general public. I ran this on my web server.
• I wrote some software in Python on the Raspberry Pi that pulls the information daily from the web server using JSON.

If this is already too much for you, consider just going to the site and setting a color: http://colormydesk.com/. If you’re really interested in that how / why, read on.

THE NOT-SO-BASICS

Forcing the Pi to Fake PWM

The first step was to get the Raspberry Pi to run some lights. Since the Pi doesn’t have 3 PWM pins, I used this tutorial on using   ServoBlaster for RGB lights.

I ran into some issues and had to use Wheezy instead of Occidentalis because its kernel version, 3.2.7 was more up-to-date. Then I used the older version of ServoBlaster, instead of the one built for the newest 3.6.11 mainly because I didn’t want to figure out how to upgrade the kernel. I used this thread to figure out kernel versions: http://www.raspberrypi.org/phpBB3/viewtopic.php?t=15011&p=278566

Building the Shield

Once that was working, I soldered the basic circuit onto some proto board. I then realized I should’ve used my Raspberry Pi proto board instead of the regular Radio Shack one. But no worries, I hooked up some headers and a custom shield was born.

CakePHP and a Web Server

I built the CakePHP site on a separate web server because I didn’t want the Pi to get overloaded. Besides, I’m a web developer and have plenty of server resources at my disposal. I then wrote some Python code on the Pi to pull the data from the site’s JSON feed with some simple authentication to protect email addresses from the public. A crontab runs every day at 6pm ET to pull the data and turn the lights on. Another one runs at 11pm ET to turn them off.

Translating Hex to ServoBlaster

ServoBlaster allows you to set a ‘servo position’ from 0 – 249. Since a color value for each red, green, or blue, can only be between 0 – 255, I decided to simply clip the last 6 values (250, 251, etc…) down to a servo position of 249. What this really means is that anything above the hex value of F9, just looks like F9. #FFFFFF, is just #F9F9F9, a dimmer white.

 The Python Code

#!/usr/bin/env python

import os

import requests
import json
import datetime
import time

import smtplib
# FUNCTIONS
def pwm(pin, angle):
angle = checkmax(angle)
print "servo[" + str(pin) + "][" + str(angle) + "]"
cmd = "echo " + str(pin) + "=" + str(angle) + " > /dev/servoblaster"
os.system(cmd)

def checkmax(angle): #PWM can only handle 249 units, so we're simply cutting the hex values 250-255 down to 249
if angle > 249:
angle = 249
return angle

def setcolor(hex):
pwm(5, int(hex[1:3],16))
pwm(2, int(hex[3:5],16))
pwm(0, int(hex[5:7],16))

# Define a Thank You Email
def send_email():
SMTP_SERVER = 'smtp.gmail.com'
SMTP_PORT = 587

sender = ''
password = ''
recipient = data[0]['email_address']
subject = 'Color My Desk: Thank you!'
body = 'Hey '+data[0]['name']+",<br /><br />"+"Thanks for setting my desk color to <span style='color:"+data[0]['color']+"'>" + data[0]['color'] + "</span> today! <br /><br />"+"You wrote: "+data[0]['details']+"<br /><br />"+"Will Wnekowicz"

headers = ["From: " + sender,
"Subject: " + subject,
"To: " + recipient,
"MIME-Version: 1.0",
"Content-Type: text/html"]
headers = "\r\n".join(headers)

session = smtplib.SMTP(SMTP_SERVER, SMTP_PORT)

session.ehlo()
session.starttls()
session.ehlo
session.login(sender, password)

session.sendmail(sender, recipient, headers + "\r\n\r\n" + body)
session.quit()

# Getting the JSON Feed
os.environ['TZ'] = 'America/New_York'
time.tzset()
r = requests.get('http://colormydesk.com/full_calendar/events/feed?start='+str(datetime.date.today())+'&api_secret=thesecret')
data = r.json()

# Setting the Color of the Strip
if data:
setcolor(data[0]['color'])
send_email()
else:
setcolor("#7733F0") # default color if no color is scheduled, aka no one loves me.

Come join this FUN event and support the MakerBar!

The MakerBar is in the process of changing its IRS filing status to 501c3. Essentially this means that donations made to the organizatiom will be tax deductible after the filing has been processed and approved. This status will help the MakerBar evolve and ultimately allow us us to offer improved facilities, shop equipment and education opportunities to the MakerBar community.

Besides a mountain of paperwork (not fun) there’s a hefty filing fee that needs to be paid (not fun). To help defray some of the expense, MakerBar is hosting it’s first public Fundraiser (very fun!) at a beloved Hoboken waterfront bar and restaurant, The Melting Pot.

The FUN!

The event is 3 hours and will be held in the bar and party room areas. Besides socializing with fellow MakerBar members and founders there will be:

Several complimentary chocolate fondue stations. Yum!
Cash bar with drink specials.
Unique member created projects for auction. Photos/details to be uploaded soon.
Member sponsored tutoring certificates for auction
A kit sales table to purchase our featured soldering/hacking kits that you can assemble at home or at one of our open nights.
In addition to the Meetup reservations online @ $17.00, we will have ticket sales at the door for $20.00 per person.

We look forward to seeing you!

Don’t forget to grab your tickets on Meetup, they’ll be more expensive at the door, plus you can check out our other classes and events while you’re on Meetup. http://www.meetup.com/MakerBar/

Eben Upton, visionary engineer behind million-selling mini-computer, to visit Hoboken on international tour

Eben Upton, founder and Trustee of the Raspberry Pi Foundation, will visit the Hoboken MakerBar Tuesday, February 26th at 7pm to talk about his experiences designing the Raspberry Pi, the $35 miniature computer designed to introduce children and adults to programming that has recently sold its millionth unit.

The MakerBar is proud to host Eben on his tour of the East Coast’s Makerspaces and Hackerspaces. The visionary inventor will meet over 30 Raspberry Pi users from the East Coast technology community to talk shop, see the latest projects, and tell the story of how his unorthodox idea became a multimillion-dollar nonprofit phenomenon.

The event will be held at the MakerBar, Hoboken’s community workshop, at 7:00pm on Tuesday, February 26th. Participants will get to tour the MakerBar’s collaborative work space, hear a brief talk with Upton about the Raspberry Pi Foundation and his six year journey, and participate in Lighting Talks about their own high-tech projects.
The Hoboken MakerBar is Hudson County’s hackerspace, a nonprofit communal workshop for learning, tinkering, and collaborating on high tech projects for fun. In its inaugural year, MakerBar has grown to 14 members who host classes and events for hundreds more. The MakerBar holds open-house events every Wednesday and Friday at 7:00pm.

The Raspberry Pi Foundation is a charity based in the United Kingdom that facilitates interest in programming by producing accessible and fun hardware. Its premier product, the Raspberry Pi, is a fully-functional computer the size of a credit card that sells for only $35 and is designed to be modified. In its first year, the Foundation sold over one million Raspberry Pi’s to children, hobbyists, educators, and others. More information is available at www.Raspberrypi.org/about.

Guests can RSVP online for the Eben Upton visit event via Meetup at: http://www.meetup.com/MakerBar/events/105715962/t/ea1_grp/?rv=ea1

After listening to hundreds of visitors whine about how “The MakerBar is too hard to find” and how “they accidentally ended up in the gym next door” and that “the door looks like a painted rectilinear turd from the set of a horror movie”, we caved to to the bellyaching. The MakerBar’s front door is now emblazoned with a breathtakingly beautiful sign!

Geek cred: The sign is made of a solid plate of 1/4″ aircraft-grade aluminum taken from the scrap heap of the US Army’s experimental manufacturing division*. A MakerBar buddy routed it in an ultra-precise CNC mill. It’s probably worth at least a hundred bucks**.

So no more of that walk-back-and-forth-looking-for-a-cardboard-sign business, just keep your peepers peeled for the MakerBar red and silver.

It also has our phone number, 1-855-MAKERBAR, on it in case you get locked out. As of today, 2/7/13, if you find yourself locked out, we recommend putting down the blunt and having a cup of coffee because the lock isn’t installed yet.

Next up: Parking!***

*Yes, this is a thing, and no, I can’t help you get an interview there.

**Don’t try any funny business, it’s attached to the door with 1/4″ one-way sheet-metal screws and ain’t goin’ nowhere. I hope for the landlord’s sake that we don’t move the MakerBar because he’ll have to replace the door.

***LOLJK

Like a “stock” Cupcake, the MakerBot’s new printer builds thingies up to 100x100x200mm, about the size of a frosted cupcake, using biodegradable PLA plastic. Jim, the generous donor and previous owner, tricked it out with a custom low-backlash extruder gearbox, underlit heated bed, and spotlights. We added some bubble levels for calibration. It’s pretty sweet, and unlike new MakerBots, it’s open hardware.

We tried to repair it with limited success. One Craft Night, Matt and Jeremy, local students at High Tech High School, dropped by and asked to play with it. Within two hours, it was almost totally working! They came back a couple of weeks later and fixed the heated bed! That’s them below looking pretty damn pleased with themselves.

If you’re new to the 3D printing thing, here’s a quick primer. These printers use fused deposition modeling; a robotic nozzle squirts a continuous bead of melted plastic as it traces the layers, building your thingy from the bottom up. Be careful watching it in action – it’s known to hypnotize MakerBar members for hours!

The printer does have a couple of quirks to watch out for. Prints are coming out about 20% shorter than they’re supposed to, and an upper layer occasionally gets misaligned and ruins the print. Feel free to come in on an Open House day and play with it, or run off simple prints anyways.

As of now, the MakerBar doesn’t have any policies around the printers – feel free to come in during any Soldering Wednesday or Craft Night and run something off in clear PLA. Chip in to our Filament Fund if you please. Prints take a LONG TIME (that RepRap part above took over two hours) so make sure you arrive early!

Jim Galvin, a former head gaffer (big-shot lighting dude) for major films, brought us his MakerBot a few months ago after a two-year battle to get it to work properly. That’s him below after futzing with it. Thanks Jim for the ultra-generous donation! You rule!