April 2013
2 posts
Beaglebone: PRU Debug Scripts →
PRU debug bash scripts
Compile pasm with -l to generate a line-by-line list of the generated code.
disable - disabled execution
enable - enables execution
init - resets and starts pru execution
mem - does a memory dump of the first memory addresses
regs - dumps the register contents (pru must be paused)
pc - shows program counter
step - steps the code. “step 5” to step 5 asm...
Beaglebone: I2C Reserved Address List
This isn’t documented. Why would it be? But, running Angstrom, as the Beaglebone comes out of the box, the following i2c addresses are reserved:
i2c-1: 0x24, 0x35, 0x50, 0x51
i2c-3: 0x1B, 0x54, 0x55, 0x56, 0x57
There are only two ic’s connected to the i2c busses: power management (i2c-1 0x24) and an eeprom (i2c-1 0x50). The others are reserved by some kernel drivers. Who...
March 2013
3 posts
Beaglebone Tutorial: UART? Gotta isolate!
LCD_DATA[15:0] are sysboot pins. This means that the levels on these pins, during boot, are used to configure the system.
Looking at the Beaglebone reference manual, you’ll notice that UART 2 to 5, have inputs on these pins. This means you MUST use something to isolate the pins until after the system has booted.
You’ll also notice that UART1 shares pins with I2C2, the cape eeprom...
New Beaglebone Preview
http://beagleboard.org/unzipped/
Uses the AM3358 chip (comparison with AM3359 in current Beaglebone).
Beaglebone SxSW 2013 Slideshow, with a few details on the new board.
Beaglebone Tutorial: PRU Custom Communication...
Part 1: Triggering the ARM interrupts using PRU events.
Part 2: Interfacing with the PRU memory.
Part 3: Interfacing with the PRU interrupts using the pruss_uio userspace i/o.
February 2013
2 posts
Ugh: oncrpc-windows library with C++ and...
oncrpc-windows on Sourceforge.
The rpc/rpc.h header that comes with this library doesn’t have the
extern “C” {}
switches around it, so you’ll get errors like
undefined reference to `clnt_perrno(clnt_stat)’
If you’re using the library in a c++ project, you’ll need to put the “extern” switch in the rpc.h header, or wrap it around the
...
Ugh: ONC+/TI-RPC using Cygwin dll - Unknown...
So, you compiled your RPC client and it runs great in the Cygwin console. You use cygcheck to get the required dll’s and move it else where, so you can run it outside the Cygwin console.
If you’re using TI-RPC, you missed a file: /etc/netconfig
The TI-RPC library uses the NETPATH environment variable or this hard coded value to look up the protocols this machine supports.
This file...
January 2013
3 posts
Idea: Line-unfollower painter
Maybe with an optical mouse for an eye, generate a “decision” from the image of the paper fibers and paint under the “head” of the line follower that would select the next direction and color to put down (or change in direction and color). Maybe stack a few standard image processing algorithms to come up with the “decision”. Might end up with some interesting,...
Lame Idea: Sound pens
Sound pens for kids. You run your thumb nail along the length of the mechanical pencil/pen and it plays back some resemblance of a word or recording by vibrating your thumbnail with some groves cut/molded onto the surface.
I loved “something generated from something else” type things when I was a kid.
To market it, could automate a cutter to do custom sounds.
Better yet, have this...
Interesting thing: Light collection from shadow...
I found some shadow living plants under a redwood tree. They had rubbery leaves that nearly felt sticky. From what I could tell from the way the light sparkled off of the leaves, they felt this way because the surface of every leaf was covered with thousands of micro-facet surfaces. This plant only lived exactly in the redwoods shadow. I can’t imagine soil conditions would be that much...
December 2012
1 post
Ugh: How to specify network interface for...
With some funky formatting so it’ll fit better….
I have the socket_ as a private variable in a class, that’s why scoped_ptr is used.
I use the Sigar API for a cross platform way to get a list of interface addresses. You’ll see people trying to use boost, but that does not give a list of interface addresses. It uses hostname resolution, which only works if you have a DNS...
September 2012
2 posts
Art Installation: Yesterday Machine
Time delay of analog tape loop with video and audio, delayed by one day. Digital for a cheap version.
Art Installation: Street corner video chat
With kiosks at major intersections of major cities around the world.
August 2012
5 posts
7 tags
BeagleBone Tutorial: BeagleBone Expansion Header...
BeagleBone Expansion Header PRU GPIO
This is a list of the PRU-ICSS high speed GPIO pins available on the BeagleBone expansion header.
4 tags
BeagleBone Tutorial: How to compile kernel modules...
This tutorial shows the commands to compile and install the “hello world” of kernel module compilation using the stock Angstrom distribution that comes on the BeagleBone.
This only requires a few opkg commands. I didn’t see this anywhere on the newsgroups or forums…no idea why.
[[MORE]]
References
Linux Device Drivers, Third Edition (Chapter 2)
Introduction to Linux...
10 tags
BeagleBone Tutorial: Configuring GPIO Pins
This tutorial explains how to locate and configure the GPIO pins for input, output, pull-up, pull-down, high-z, etc.
I couldn’t find this information clearly stated in any one place, so here’s my attempt. If the TI wiki was actually a wiki that allowed people to edit it, I’m sure something like this would already be there.
[[MORE]]
References
Technical Reference Manual:...
6 tags
BeagleBone Tutorial: Accessing Main Memory From...
This tutorial shows how to access any part of the main memory from within the PRU, and reasons you shouldn’t.
[[MORE]]
References
PRU Reference: AM335X PRU Reference Guide from the AM335X PRU Package (usage tutorial)
Technical Reference Manual: AM335xARM Cortex-A8Microprocessors (MPUs) Technical Reference Manual
PRU Local Memory
Each PRU-ICSS has local memory that, from the perspective...
Idea: Remote temperature sensing for combustion...
Using a few infrared detectors with various wavelengths placed near the intake valve, you could pretty accurately estimate the maximum temperature inside the combustion chamber when the valve opened.
The internals of the combustion chamber would reflect infrared pretty perfectly, allowing it to bounce out of the intake valve while it was opened. The multiple infrared detectors would have...
June 2012
1 post
Idea: Motion Sickness Surface
To help prevent car sickness while reading, use the “make sure the horizon is in view” approach by back-illuminating the page you’re reading with a pattern that remains, from an inertial perspective, stable.
A notepad holder/device cover (like iPad) with a low res led pattern, a gyro, and an accelerometer. The led matrix would display a pattern that would remain relatively...
May 2012
1 post
Idea: Pseudorandom display
For a display, have an agreed-upon, and constantly changing, pseudo-random pixel/row/column update order. This would propagate up to the actual row/column selectors. This would mean that the signal couldn’t be observed except at the actual output of the display row/column selector, and would have to monitor each individual to grab the video data. This would mean monitoring and post process a...
January 2012
1 post
Idea: If I were to make a virtual globe
Earth globe:
ideally, Full google earth integration
realtime weather display with forecasts on touch
“pinch” zoom, with display centered at touch point
flick rotate
tap drag -> rotate with friction
tap tap drag -> continuous rotate
begin rotate after timeout
realtime/selected night/day...
October 2011
4 posts
6 tags
Python Tip: Properties with a parameter
This is probably”unpython” and whatever, but I do a lot of automation, and being able to access properties based on some index (like a port number) is pretty important. This is especially true since getting a property isn’t reading a variable, it’s actually reading the value from some piece of equipment.
And, in case pastebin dissapears:
# This was created based on a...
Silly Idea: Clockless Watch
Using a metal brush, a low pass filter, and a schmit trigger as digital clock source for the calculation circuit, you could make a horribly inefficient electronic watch that used the position of the sun (by a low res ccd or even photodiodes) and a compass to calculate the time. Can’t use a crystal or rc, because that would be cheating! Might as well just have it keep the time!
Idea: Cracked wafers?
Relating to the bandwidth segregated data transmission…
I picture chips
|=======| - photoelectric layer
|=======| - charge storage
|=======| - adjacent storage distribution
|=======| - logic
|=======| - diode and transistor junctions (photo).
photoelectric layer to supply power, probably wouldn’t have to be too efficient
store and filter the power
some sort of low voltage...
Scrambled for distribution?
Is it possible to scramble data so that the signal can be broken into channels based on an average over time? Usually in communication, the average is kept to zero using a known and syncronized psuedo-random sequence (a scrambler). Could the sequence be modified (by observation and modification or sub-channel) to allow distribution of data based on bandwidth capability? This would allow a bus with...
May 2011
3 posts
Idea: Wireless turn signal
Fancy mirror turn signals LED strip activated by wireless transmitter attached and powered to the actual turn signal light. The LED strip would be powered with 12v accessories.
Idea: Tire wear measurement
A low power, inductor powered, cheap microcontroller embedded in a tire could be used to detect and warn of tire wear. The microcontroller could measure the change in resistance of thin wire molded into the tires surface. When these filaments broke, from being exposed to the roads surface, a tire wear indication could be sent to the driver. When deeper filaments break, a warning indicator could be...
Idea: Automated map generation for driving video...
Pretty obvious idea. Using the aerial and street view of Google Maps, and some simple texture/feature recognition and “design rules”, maps for driving video games could be made. Actual road data would be pretty reliable. Stop lights and signs could either be found using street view at each intersection, or randomly assigned since players will fly through them anyways. Buildings,...
April 2011
2 posts
Useless Idea: Diffraction pattern on linear CCD...
For a cheap, high precision position sensor, could use a linear ccd from a scanner, project a laser through a diffraction grating (or pinhole) with a known diffraction pattern, then do some simple curve fitting/energy minimization of the visible pattern to find the position. Curve fitting rather than point tracking would be used to get sub pixel resolution. Since the light is directly from the...
Idea: Cell phone traffic lights
Sniff cell phone control channel data to find ESN. Calculate CRC32 or something similar for privacy, track movement by watching where the number pops up. Do this to all “visible” cellphones to create traffic flow pattern in town for light timing.
???
Edit: I suppose the cell companies could probably sell the data.
March 2011
1 post
Idea: Baby temperature monitor
Just a simple temperature monitor that you put in your babies blanket that starts beeping if the temperature gets too high or low.
November 2010
2 posts
Idea: Cloud redirect service
To post a link to an image or a document, the link, rather than pointing directly to the document resource, would point to the redirect service. This would check to see if the cloud resource was available and, if not, change the redirect to an available/redundant resource….maybe even hosted by a different provider. It could even perform load balancing by randomly choosing the redundant...
Speckle interferemotry for blood glucose level...
Maybe use speckle interferometry to measure blood glucose level by looking at the index of refraction of the aqueous humor of the eye (the clear bulge part in front of the iris).
Using a single laser
<to be continued>
Using absorption: http://iopscience.iop.org/1742-6596/277/1/012053/pdf/1742-6596_277_1_012053.pdf
Patent using interferometry to measure index of...
September 2010
2 posts
Kids Toy: Squeaky Feet
Kids toy!
For a fancy version, using pressure sensors in or under the shoe, for a cheap version, using an accelerometer or spring mass switch. Controller could be leg or belt mounted.
When you walk, the controller would play back different sounds. Stomping, squeaky floor, etc. For the two sensor version, the sounds could be multi part or just segments played back as you moved forward. That way,...
Temperature Sensor Array
Use the top metal layer of a CMOS process to build structures that resonate at a specific frequency. Use the layer below to excite the resonance. Use the layer below that to build a similar structure and use as a reference. By measuring the difference in frequency between the two, small changes/differences in the structure (like length) could be detected. If possible, coat the top layer to a dark...
July 2010
4 posts
Idea Idea: Compass belt implementation
In the wired article about the compass belt, a complaint was that the motors were always buzzing away. I think a better implementation would be to only vibrate the motors on a change.
So, if you’re facing north, as you rotate, the motors would vibrate with direction change, but only remain vibration for a maximum of 500ms.
Idea: Fluidised flour bed for opticle table...
So, when making holograms, the total movement between the light, film, and object can’t be more than 1/2 to 1/4 the wavelength of the color of light you’re using (red is around 650nm). The less movement, the better.
Would flowing air into a block of flour (baking soda, or something similar), supporting the optical table, work to isolate vibrations? It would act like a super dampened...
Software Idea: Jump alarm clock
An alarm clock that looks for a “jump” pattern from the accelerometer. This should be pretty hard to copy with your hand once “calibrated” with a real jump. Yeah, so I have trouble waking up.
Software Idea: Excersize Helper
This has probably been done…but…
A little program that uses the accelerometer on a phone to count push-ups (not the diapers), jumping jacks, and sit ups…things you can do in your living room. It would be somewhat game oriented, where it would have a silly little beat and a fun “Wii” type voice counting your repetitions and encouraging you. For instance, if you...
June 2010
2 posts
Idea: Touch Pad Typing
Copy paste from chat, cause I’m lazy… me: Hrmm…I just had a thought for the toupad typing problem. me: You can’t feel the keys, so it’s easy to drift.So, why not have a vibrate that changes depending on how close to the edge of teh key you are?so, the more on center, the more “right” it will feel.the closer to the edge of the key you get, the more...
Idea: Building Dot Matrix Printer
It would use a small robot that would move around on the buildings face by pulling tethers. Electric paint sprayers and a vacuum hood would do the bulk of the work. Refilling would be done by retreating to home. Power would be delivered over one of the tethers. Colors would be mixed mid spray to keep from having to premix paints.
Ideally, the whole paint process could be completed at night.
...
April 2010
2 posts
Idea: Looking at the control response of people
Say you have a linear motor that can apply a force to a stick with a mark on it. You tell the person holding the stick to attempt to keep the stick positioned so the mark stays at some fixed point. What does the step function look like? Is there a difference between an athlete and some regular guy? How well can a person control a bouncing or nonlinear or some other crazy force pattern? How does...
Idea (not unique): Using deconvolved images for...
The idea was to use deconvoluted images to make an image sharper when viewed by a near or far sighted person. Could make distant signs sharper or help diagnose eye problems. For instance, a person with eye problems could sit in front of a screen (at a known distance, far or close). Deconvolved images could be displayed on the screen where the person would press buttons indicating which...
March 2010
5 posts
Idea: Redundant Cloud
In response to Picasaweb going down, I posted this:
“Hrmm…it sounds like someone needs to make a cloud redirecting service. To post a link to an image or a document, the link, rather than pointing directly to the document resource, would point to the redirect service. This would check to see if the cloud resource was available and, if not, change the redirect to an...
Data: Weight by resturaunt
It would be interesting to see the distribution of the weights of people entering different restaurants. Could place a “mat” scale at the entrance, then log all of the weights.
Idea: Resonant weight
Old idea. A voice coil with a weight would be attached to a surface. The weight would oscillate and tune to the frequency of the surface it was attached to, creating the most noise/vibration possible! Lots of mischievous uses (what if you attached it to a piece of plate glass!).
Might have some use in vibration testing, where it would find all of the vibration frequencies, and give you the...
Silly Control Idea: Splash free...
Wave dampening
Bob-on-a-string array that would be controlled to dampen (and possibly detect) waves in a liquid, such as a pool or shipping container. If placed in the corner of a pool, the bob array would absorb the wave’s energy.
“No Spill” Coffee Cup
Fluid would sit in a portion of a gimbal. A few vertical capacitive sensor strips would be placed around the cup to detect...
Idea: Dissolvable Plastic?
Would be interesting to look at the chemicals created during landfill decomposition. Then, knowing these chemicals, create a packaging that dissolves in their presence, ideally creating more to speed the reaction.
February 2010
3 posts
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