Ezra^3 - let's make things happen. » Electronics

NxJ Revenue Indicator

ezraezra — Mon, 30 Sep 2013 12:22:18 +0000

Visual Monitoring (Part II)

Foreword:
On Friday the 13th (9/13/13) J.O. and I participated in the company-wide Next Jump Hackathon 2013. We decided that instead of focusing on a software-based project, we should do a hardware-based project. This is a technical follow-up on our original project post, which can be found here

How It Works:
A cron job runs two Shell scripts (revenue and site status) every 20 minutes and minute, respectively.

The site status Shell script first cURLs an internal dashboard that contains the status of the Next Jump sites. The site is then piped into a stream editor (sed) to pick out the graphic name used for site status. This value is grep’ed to check it it contains a certain graphic. We finally run an snmpset call passing either an on/off integer value, depending on the boolean result of the grep call.

GET_CURL=$(curl -ks | sed -n '/nettable/,/Production/p') echo $GET_CURL | grep -q 'light_green' if [[ $? == 0 ]] ;then $SIREN_ON else $SIREN_OFF fi
As for the revenue status Shell script, the script cURLs another internal dashboard that contains both goal and current revenue. The result is then run through a series of stream editor (sed) and pattern-directed scanning and processing language (awk) calls in order to pull both the goal and current values.

GET_GOAL=$(curl -ks | sed -n '/totalRow/,/avgRevenue/p' | sed -n '/goalRevenue/,/avgRevenue/p' | awk 'BEGIN{ RS="K<\/td>"}{gsub(/.*>$ /,"")}1{print $RS;exit}' | sed -e 's/^.*">$ *//')

In order to visually tell when the revenue status script ran, and to give the project flair, we added a small Shell script inside the revenue status Shell script to blink the revenue lights (red, yellow, green) in a continuous daisy-chain pattern for two cycles.

until [ $COUNTER -lt 0 ]; do $RED_OFF $YELLOW_OFF $GREEN_OFF $RED_ON $YELLOW_ON $GREEN_ON let COUNTER-=1 done

Once we return back to the revenue status script, an snmpset calls are made to turn off the revenue lights, followed by another snmpset call to turn on the socket that corresponds to the revenue standings.

Construction:
The visual monitoring body is composed of 3/4″ x 10″ solid oak board and is fastened with 1.5″ corrosion proof deck fasteners. It houses a smart PVD devise and is wired to the lighting system via 110 volt grounded pig tails. Leviton Ceramic lighting fixtures with NxJ beer pint glasses contain the heat created by the CFL lights and add to the decor. V2 will consist of color, labeling, and branding the devise, as well as installing an audible alert for coronitas.

Bill of Materials:
(1) APC Switched Rack PVD
(1) 110v Red light siren
(3) Beer Pint Glasses
(3) Feit Electric 13-Watt (60W) Twist CFL LightBulb (Red, Green, Yellow Bug)
(1) Lava Lamp
(3) Leviton Ceramic Keyless Lamp Holder
(36) Drill Screws
(1) Ethernet Cable
(3) Lamp Cord Set

Resources:
MAN Pages
Steve B. (Fellow NxJ enlightened in the art of Shell scripting)

Snapshots:

Visual Alerting

ezraezra — Sat, 14 Sep 2013 16:48:33 +0000

NxJ – NxJ Hackathon 2013
Name: Visual Alerting
Platform: Web, Server, Electronics
Author: J.O. & Ezra Velazquez
Release: September 14th, 2013
Technology: Unix, Bash Shell, SNMP, Ethernet-Enabled power-strip, lightbulbs
Source Code: Currently Unavailable
Version: 1.0

About: A physical alert & monitoring system that reports on site outrage, revenue progress for the week, and outbound mailing progress.
Intent: To give key company metrics a physical attribute. While seeing a red light go off in a dashboard on a site means something is wrong, seeing a physical siren go off brings a real sense of urgency to the physical world since as humans we instinctually react to the physical and what is right in front of us.
Personal Intent: To work on shell scripting, something I’ve been meaning to learn more about but never had a chance to fully pursue.
Backstory: A week or so ago J.O. approached me about this crazy idea he had: instead of relying on different dashboards all throughout the internal system, how about having a device that could be displayed in a public space and display key monitoring statuses. I was intrigued and joined his team, mostly because it sounded like an awesome project and because I would doing “physical computing”.
Process: We first figured out what exactly to display on the device. After scratching our heads, it made sense to display site outage with a red light siren. The revenue status for the week would be best displayed with a stop-light approach, with red being behind goal, yellow being near goal, and green exceeding goal. Finally, given that we have outbound emails going out for great periods of time, it made sense to use a lava lamp. As for the code to run it all, we decided to use an ethernet-neabled power-strip that was lying around that accepts SNMP calls, which can be easily triggered with a bash script running every minute or so on a cron job.
Success: The actual physical device got built, and we where able to detect site outage & revenue progress via scrapping the site. Even though we could have easily used credentials to run an SQL script to check revenue status, we believed that wouldn’t make it a real hack.
Failures: While the mercury light got installed and be responsive, we ran out of time to write a shell script that would detect outgoing mail status.
Tips:

Rely on the MAN pages. They will explain what all those crazy characters after the command mean.
Always wear protection when doing woodwork
Piping will save you a great deal of time when you need to write a script quickly and don’t have time to clean it up
Try to work with people with different work backgrounds than you. You’ll learn a great deal, and have some bonding time in the process

GALLERY:

Photo of me wiring a lightbulb stand by @praetoriansentry

Rodney the Red Monster

ezraezra — Tue, 14 Dec 2010 17:18:56 +0000

Rodney the Red Monster is a little shy of humans, the weirdest creatures in the known universe.

Background:

In the depths of Southern New Jersey there lives the mythical Jersey Devil, a monster so fierce and revered that no one dares travel to its swamps. I was ready to find the worst, and instead found Rodney.

This is his story.

How It Works:

A proximity sensor, built onto the base of the robot, checks for objects within a predetermined range every 1 second. If an object enters the sensor’s range, the neck of the robot collapses into its body. This action is achieved by choreographing the movement of the base & middle servos, which act as the robot’s neck joints. Once the object leaves the sensor’s range, the robot “pops” its head back out by powering the two neck servos.

The top servo motor, which is the smallest of the three, moves the eyes of the robot back and forth when the neck is fully elongated. The servo motor moves the eyes back to their original position when an object enters the sensor’s range.

The sound module plays audio clips while an object is outside the sensor’s range. When an object gets within range, the audio track stops.

Testing:

Construction:

The skeleton of Red Red is made of (3) three scrap pieces of wood found at the ITP shop.
The neck is made of thin aluminum sheet strips.
The body cavity is made of (2) two oatmeal barrels.
The fur is made of “fancy” red yarn (that’s what the store calls it, I like it because it feels, well, furry).
The extremities is made of styrofoam and tube cleaners.

Notes:

The LEDs are used as status lights.
Green LED lights up when the audio-module is playing files.
Red LED gets brighter as an object gets closer to the proximity sensor.
The potentiometer is used to set the signal strength from the audio module to the LM386N chip.

List of parts (Bill of Materials):

(1) Arduino
(1) LM386
(1) Audio-Sound Moule – SOMO-14D
(1) Infrared Proximity Sensor Long Range – Sharp GP2Y0A02YK0F
(2) Servo – Large Full Roation
(1) Servo – Small
(3) TIP120
(1) LD33CV
(1) Speaker – 0.5W 8ohm
(2) 220 uF capacitor
(1) 100 uF capacitor
(1) 10 uF capacitor
(1) 1K resistor
(2) 470 ohm resistor
(2) 10 ohm resistor
(1) 10K potentiometer
(1) Red LED
(1) Green LED

Resources:

ITP Physical Computing Tutorials
Audio-Sound Module Datasheet
LM386 Audio Amplifier

Solutions:

Snapshots:

Easter Egg:

Media Controller – IPC

ezraezra — Tue, 16 Nov 2010 00:11:34 +0000

Phase 3 of 3 for Media Controller Project. Having a deadline glomming over us, the group shifted into high gear.

Ladies and gentlemen, my group’s media controller project.

In a nutshell, MousePed is a giant mouse pad music controller for your feet. Step on one of the 15 pads hidden underneath the mouse pad, change the volume of individual tracks.

Equipment for this project is as follows:

(1) Arduino
(1) CD74HC4067
(15) 100-ohm resistors
(15) home-made pressure sensors
(1) XBee Wireless Shield
(1) XBee Explorer Dongle
(2) XBee 1mW Chip Antennas

A few notes of ome of the equipment:

CD74HC4067 chip – Arduino decides which of the 16 available channels to listen to by using a 4 level truth-table.
XBee Wireless System – Both XBee Antennas talk to each other using the handshake method. This method makes sure that the buffer will not overflow by only sending data when requested.

References used are from CD74HC4067 datasheet, Tronixstuff (XBee shield), and ITP Tutorials (XBee modules).

Solutions:

Intrusion Alarm Revisited

ezraezra — Thu, 11 Nov 2010 02:08:47 +0000

This post is a response to an exercise in the book “Make: Electronics”.

In this exercise, the focus in on creating an alarm that once it is set off, it latches onto that setting. When the alarm is set “on”, power goes through the switch (a jumper cable in this experiment) to GND instead to base of the transistor. Once the alarm is set “off”, buy opening the switch (or removing the jumper cable that went to GND), power is applied to the base of the transistor, which activates the relay and powers the signal of the alarm: a green LED.

A signal diode is used in this experiment. This piece of hardware blocks “bad voltage” from flowing back up the wire. For this experiment, power from the relay has the potential to flow back up to the emitter and base of the transistor and to the switch. The only reason it has this potential is because the NO leg of the relay is not connected to GND. If it was, a diode would not be needed.

If you take a look at the pictures, you’ll notice that there is an exploded LED. Originally the LED in this experiment, which was red, didn’t have a 2K2 resistor to GND. When the circuit was plugged to PWR, 12volts raced to the LED, which caused it to explode and create quite some noise. This was a friendly reminder to make sure all components are given the proper amount of power.

A Pulsing Glow

ezraezra — Tue, 09 Nov 2010 20:28:00 +0000

This post is a response to an exercise in the book “Make: Electronics”.

In this exercise, the focus was on creating as oscillator that gradually flashed an LED. In previous examples, flashing LEDs seemed very robust; they where either fully on or off. With the assistance of various capacitors and resistors, a LED can be made to gradually flash, which makes it have a more “organic” feel.

In the wiring of this experiment, two capacitors where used: a 100uf on the anode of the PUT transistor and a 220uf on the cathode of the transistor. The values of the resistors on the gate and anode of the transistor where greater than on the cathode. This allowed the LED to slowly discharged energy sent from transistor’s cathode. By having higher value of resistors on the anode compared to the resistor on the gate, it increased the time it took the capacitor to charge before the “gate was open” to the cathode.

It can also be noted that I manage to “squeeze” all the components onto a small section of the breadboard. If this experiment where to be put on preforated board for a project, it would be best to take the last amount of space.

Broil an LED

ezraezra — Mon, 08 Nov 2010 20:23:05 +0000

This post is a response to an exercise in the book “Make: Electronics”.

In this exercise, an LED is broiled. The purpose is to explain that if the wrong soldering iron is used, electronic components can be damaged. A good way to prevent damage is by using heat-sinks when soldering components together.

Since I have destroyed couple of LEDs in a previous project. (Stupid Pet Trick), I decided to waive the experiment, but still read the experiment’s background, tools, and theory sections.

Joining Two Wires Together

ezraezra — Sat, 06 Nov 2010 03:45:59 +0000

This post is a response to an exercise in the book “Make: Electronics”.

In this exercise, two wires are soldered together. A proper solder is made by first heating up both wires with the soldering iron, and while the soldering iron is touching both wires, the solder is pushed onto all three surfaces.

Since I have been soldering in previous and current projects (Stupid Pet Trick, Media Controller Phase 1), I decided to waive the experiment, but still read the experiment’s background, tools, and theory sections.

A Modular Project

ezraezra — Thu, 04 Nov 2010 20:21:44 +0000

This post is a response to an exercise in the book “Make: Electronics”.

In this exercise, the focus in on learning how to use Programmable Unijunction Transistors, also known as PUTs. With the ‘belly’ of the transistor facing your right, the top leg is the anode, the middle is the gate, and the bottom is the cathode.

What makes PUTs different from the previous transistors in earlier projects is that the anode must be ‘more positive’ than the gate in order for the power to go to the cathode. Say, if the gate had a 2k2 resistor and the anode a 50K resistor, no power will travel to the cathode. No power is traveling because the gate has ‘more power’ than the anode. The gate is blocking energy from travelling to the cathode.

By adding capacitors in parallel to the anode, enough ‘power’ can be collected that the anode will eventually be ‘more positive’ than the gate, which causes the capacitors to discharge and send power to the cathode. The cathode is connected to an LED, which lights up until the power level in the anode drops below the power level of the gate.In theory, this process acts like a timer which flashes an LED. Keeping the capacitor the same, the LED can be made to flash faster by decreasing the resistance in the anode or increasing the resistance in the gate.

Transistor Switching

ezraezra — Tue, 02 Nov 2010 05:49:55 +0000

This post is a response to an exercise in the book “Make: Electronics”

In this exercise, a transistor (type NPN) is used to amplify power to an LED. On the transistor itself, its “collector” is connected to PWR, “base” to a momentary pushbutton (type SPST), and its “emitter” to an LED.

In a nutshell, the “collector” provides a steady source of PWR. The “emitter” can only send power out when the “base” is given power. When the pushbutton is pressed, it allows power to go to the “base”, which causes power to amplify and be sent out via the “emitter”. The transistor acts as an amplifying switch.

If it was a a type PNP transistor, the “collector” would be connected to GND, the “emitter” to PWR, and the “base” to GND. In order to have power go from the emitter to the collector, the base must have negative voltage.