Feb 10

Some DAC fun


My sensor peripheral interface design lab has us working with a 4 channel DAC. The requirements are to make a sine and triangle wave- but since those are kinda boring I thought id do some experimentation in XY mode 🙂

Feb 10

Future Plans 2/24/10

-Mar 30 leave for OSAKA

-Upgrade to lithium packs?

-Hottub Monitor

-Interactive ‘rave’ visualization


Feb 10

Motorcycle Ride Profiler

[EDIT: ZOMG. rotation matrices are awesome. wish I understood those when I first started this… ]

[EDIT 2: Google released an Android app that does much of this based on your phones accelerometer/gps. i feel discouraged. suppose I’ll be moving on to a different project now.]

My current Microcontroller project is a data logger that keeps track of position, velocity, and acceleration of a motorcycle. It will use this information to generate a visualization of the ride , presenting the raw figures , as well as lean angle, incline, and engine rpm which can be extrapolated as follows:

Straight Standing FBD

Straight Standing FBD

Calculation of the lean angle

Calculation of the incline angle

Calculation of the incline angle

Determining lean angle when at an incline is somewhat more complex.. and I have yet to sit down and work through the math – but ill be sure to post as soon as I do. And of course , as it doesn’t have (but probably should get) a gyro, these only apply to the static case. I’ll probably need to get clever in the code to figure to approximate out angular rate without gaining too much error

Engine RPMs will be calculated by performing an FFT to convert the acceleration magnitudes to frequency domain, band pass filtering (between ~8 and 300 hz I expect) to isolate the noise created by the exhaust and/or the engines power strokes. This frequency information will be examined and the range with the most energy will be assumed to be from the engine’s rotation.

where I am now:
I have prototype uC hardware together and logging data (pictured below) the next step is mounting it to my bike and reving the engine to collect data so that I can see if my ideas on RPM determination are valid. Schools been busy lately, so this may have to wait.. but stay posted!

Motorcycle Profiler Hardware

Motorcycle Profiler Hardware

Calculation of the lean angle

Continue to Future Plans

Feb 10


Inspired by our hosting of the 2010 Fermi Cup (A graduate Electrical&Computer Engineering vs Materials Engineering keg off) I decided to throw together an appropriately geeky microcontrollered beerbong installation at the bottom of our staircase
This was a good first way to break in my shiny new mbed microcontroller, as well as to continue flirtations with the Processing language.
Pics Below:

Continue to Ride Profiler

Feb 10


In LOVE with all my courses – how it should be.

ECE 153b – Sensor Peripheral Interface/Design
More on hardware description languages; field-programmable logic and ASIC design techniques. Bus interfacing. Mixed-signal techniques: A/D and D/A converter interfaces; video and audio signal acquisition, processing and generation, communication and network interfaces, basic motor control (PID).
Currently working on a circuit/program which acquires an signal via ADC, and replays it over DAC. Full Lab Report coming soon!

ECE 181C / ME 170C – Intro to Robot Control
Overview of robot control technology from open-loop manipulators and sensing systems,
to single-joint servovalves and servomotors, to integrated adaptive force and position
control using feedback from machine vision and touch sensing systems. Design emphasis
on accurate tracking accomplished with minimal algorithm complexity.

21.7 second Wall Following bot:

RoboRat Solo Time Trials Tomorrow!
RoboRat Final Competition W2010

ECE 130B – Discrete Time Signal Processing
Analysis of discrete- and continuous-time linear systems in the time and frequency
domains. Superposition and convolution. Bilateral and unilateral Laplace and Z
transforms. Fourier series, Fourier transforms, discrete Fourier transforms. Filtering,
modulation, and sampling. — Usefull Stuff!

MAT 259 – Information Visualization
Exploration the visual organization of information. Lectures, readings and technical demos will focus on a range of conceptual models of data visual mapping as implemented in various disciplines, artistic, statistical and scientific, that are used to represent information visually.

-2D Spatial Visualization link

-3D Interactive Visualization
Coming Soon!

Continue to Chuglet Project

Feb 10


Classes kinda boring this quarter.

not inspiring.

Continue to W10

Feb 10


So as you know, during the 2008-2009 school year I chaired the UCSB IEEE club.
Through an interesting chain of events, I was asked, through the IEEE club, to direct a 2 unit lower division course in µCs.
I had just learned about the Arduino platform, and , although basic, seemed to be ideal for an freshman introductory microcontroller course.
Course Syllabus/ Outline shown below:

Some of the Final Project posters – also posted on the 4th floor, HFH:


For Spring 2010, Bob Frankel will be taking over/evolving this course into ECE 194 which be upper division and incorporate his EM language. This is very exciting! Stay posted for updates!

Continue to F09

Feb 10


Physics 15 lab – FerroFluid Fountain!

FerroFluid Fountain

This was quite a fun project; completed as part of the honors/ccs physics lab series in which students are commissioned to design and build a physics demonstration for use with undergrad lectures. The basin holds ~60 ml of the ferrofluid which is sucked into the middle, pulled to the sides, or drawn up the centerpiece by electromagnets whose field can be manipulated to be constant or exhibit patterns dictated by the array of buttons/knobs mounted to the front panel. I should really upload a picture of the whole unit.. Anyway, this also resulted in my group and me being invited to show it off on behalf of ccs at a benefactor’s event – and man do they feed people at those events well 🙂

FerroFluid Fountain! from Z R on Vimeo.

ECE 152b Digital Design Methodologies – like being GOD!
Build a 4-bit RISC Computer!! Register Transfer Level Design, Clocking, b bus architectures, pipelining, control units, memory systems, microcoded systems.

Continue to ECE94R

Feb 10


– ECE 152a Digital Design Principles – enlightening
logic gates and their operation in larger circuits – latches, flip-flops, adders, etc. Also state machines, and FPGA implementation.

-ME 12S – Basic Machining – Useful

continue to S09

Feb 10

Curiosity becomes Obsession

I could probably use that title for a number of things… however here I am of course talking about Voltage

Short story: Broken down $200 craigslisted GS450 becomes [after several months of of grunting, grinding, welding, searching, researching, spending, assembling, and spraypainting,] my pride and joy 72V battery powered Electric Death Machine!

For the technically interested, the drivetrian consists of a D&D Systems separately excited motor powered by a CAN programmable Sevcon controller and 72v, 35Ah of sealed lead acid. Charging is accomplished with 6 individual four stage 7amp constant current “smart” chargers, and a Kelly DC-DC converter is used to provide a 12v signal to the ‘standard’ motorcycle electronics. Regenerative braking is automatically activated with release of the throttle, and can be modulated with a second lever located on the left handlebar (think engine braking and clutch lever on an ICE bike).

The project was ‘finished’ back in April ’09, in time to be ridden to and featured in Santa Barbara’s Green Car Show, However after riding on and off for several months, the SLA batteries spouted their last electrons and are now sitting at an uncomfortable -5v.. It is well known that SLA batteries SUCK anyways (and actually ended up being my performance bottleneck), so I am saving up and hoping to swap in a Lithium pack sometime hopefully this year. Current lithium packs have greater energy density, are lighter, have better discharge characteristics and longer lifespans than sealed lead acid, only problem is they are (as of this writing) ~4x the price (a pack and BMS system for my motorcycle would run around $3k) … A LiFePO4 pack would mean significant gains in terms maximum range and acceleration.

I have most of the parts laying around for an embedded security system, which, initially will require fingerprint authentication to activate ignition (O.K. its not really an ignition, its a primary contactor…) , and eventually will also include GPS and GSM/GPRS communication so that the bike’s location can be queried via cell phone, or alerts can be sent in the event of invalid activation attempts. However I have found my desire to actually implement this diminished as, until I replace the batteries, the bike is unrideable anyways..

More pretty Pictures:

Also be sure to check out http://www.elmoto.net/ , probably the best electric motorcycle resource out there.

Continue to W09


r/w_ blog : 10-03-2023
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