Bot Thoughts's Posts (13)

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IMUdino on Kickstarter -- a really tiny 10DOF IMU with Bluetooth. It was covered by Atmel blog.

The Kickstarter has 3 days left.

Surely there are UAV / Rover applications in addition to Minority Report style UI and Wearable applications, right?

Generally speaking it looks like a pretty neat product. Enough that I backed it so I could get one for myself. :)

I have been in touch with the guy behind all this over the last couple of years as a fellow seller on He seems to be a good guy. He's been making these by hand to date, but it's quite a task for this unit, so he's hoping to start outsourcing assembly now, hence the Kickstarter.

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Give All the Robots Eyes to See! OpenMV.


The OpenMV camera module will be the lowest cost, most hackable machine vision platform out there, because Ibrahim, the creator, and I want to change the nature of hobby and educational robotics. We value your feedback and suggestions* as we gear up for a Kickstarter campaign.

  • Possibly as low as half the cost of the Pixy in sufficient volume;
  • Scriptable in Micro Python;
  • 25fps face tracking, 60fps blob tracking;
  • Viola-Jones object detection;
  • Loads OpenCV cascades from microSD;
  • The current version measures only 1.0" x 1.3";
  • Compatible with OmniVision 0.3MP OV7660, 1.3MP OV9650/OV9655, or 2MP JPEG OV2640;
  • STM32F407 MCU now; considering faster STM32F429;
  • Exposes SPI, I2C, and UART pins, can run SPI with I2C or UART;
  • Programming header exposed;
  • Python scripts load off the microSD card;

We want OpenMV to become the Arduino of machine vision, bringing eyes to more robots and simplified tools to more hobbyists and students to easily achieve incredible things with their creations.

Imagine the possibilities. How about a bathroom mirror and light that turns on when you look into the mirror? Or a doorbell that rings itself when someone shows up at the door. Or detect and avoid Sparkfun AVC barrels. Use two OpenMVs for depth perception. What about some kind of sight-based UAV position reference with color ground markers?

Here's a video of the face tracking:

The camera can detect minions. :)


Here's the Python IDE, with frame buffer capture, tracking a red ball in just a few lines of Python:


*We'd love to hear your thoughts and feedback on this module. Please post your comments/thoughts here.

Or, if you want to contribute to the think tank, join the google group [here]

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Anyone else building an autonomous rover perhaps for Robomagellan or Sparkfun AVC? Do you have a multiplexer on your one-off, scratch built autopilot solution? If not, I built something just for us. :)

Picture your robot driving right at a curb or a wall. No problem, just take over with an RC multiplexer installed. It's saved my bacon plenty over the last couple years. APM users no doubt have many similar experiences with their built-in mux.

They're now available for pre-order for $12. I'll be ordering R0.2 boards soon.

Now, you may recall the AVC prohibited RC transmitters. Well, the mux on Data Bus been invaluable during testing, primarily. I'll be using one of these boards on Data Bus in prep for The 2014 AVC.

  • 3 R/C channel multiplexer, designed especially for rovers
  • Reliable, standalone design; keeps running even if your autopilot MCU doesn't
  • Color-coded pin headers for fast, correct installation
  • Fully assembled
  • Easily select between autonomous and manual control
  • Two inputs: R/C and MCU, clearly labeled on the board
  • Two LEDs indicate autonomous or manual control.
  • Onboard regulator
  • Compatible with common 5V, 5.5V or 6V BEC
  • Power rail transmits power from BEC to Receiver, Servo, MCU
  • Firmware pre-loaded or program the ATtiny13 yourself
  • Open source (hardware and firmware)



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Sharp Distance Sensors with I2C


For my own rover, Data Bus, I've been working on a board that converts Sharp range sensors to I2C.

I ran out of analog ports and had to prototype an I2C solution for my obstacle detection. I have this problem on all my robots. Pokey has too few analog ports. And I want to run a few of these on my RPi tele-rover.

They'll work with any Sharp ranger. For that matter, with any analog sensor (ideally at 3.3V or 5V). I plan to test a Maxbotix Sonar module soon.

Up to 27 of these on an I2C bus without re-programming the base address.

The firmware's oversampling, decimation and low pass filtering increases resolution and lowers noise floor. The analog anti-alias filter helps too. Performance is really good. Here's a pseudo-theremin demo:

They're running ATtiny44As. 6-pin AVRISP header doubles as I2C interface -- SPI and Serial on the newer revision is possible; I break out an ~SS pin. I also break out 2 GPIOs for the heck of it. I'm testing out SOIC and QFN versions.

If there's anyone who's building a project using analog rangers (Sonar, Sharp, other) and wants to try these let me know.

I have example code for Arduino, mbed, Raspberry Pi, and Propeller so far.

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Data Bus mbed baseboards are now available on Tindie as a fundraiser! I figured maybe some folks wanted to experiment with their own algorithms and want a head start on their 2014 AVC ground vehicle entry. :)3689524829?profile=original

I ordered a very small run from OSHPark (hopefully they arrive before June 8, but if not oh well), but will order more as needed.


  • Three UART ports, one 3.3V, two 5V, series resistor protection
  • Five I2C ports, all 3.3V
  • ESC and steering Servo connector
  • Dual wheel encoder port
  • Port for 3 buttons (onboard UI)
  • Onboard 5V regulator powered by ESC 6V BEC powers 5V UARTs
  • Separate mbed supply rail to keep noise out of your GPS.
  • Filtering / bypass caps

If there's enough interest I'll add some additional features.

This baseboard is in its fifth revision (version 4 was onboard when Data Bus took 3rd in the 2012 AVC).

Just get an mbed, load it up with my code ( and here), add an L3G4200D gyro, Venus or uBlox GPS, wheel encoders.

On Data Bus I run external power supplies, a separate encoder schmitt trigger board, a safety cutover so I can take control of the robot during testing, and I also run a Venus GPS, Pololu MinIMU-9 (for x axis gyro).

All the code is open source:

Data Bus source code repository

AVC2012 code on

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2013 Sparkfun AVC entry video

I put together a short video of Data Bus driving in autonomous mode in the rain. Hopefully I got the video in before the deadline. We'll see...

Data Bus is configured to drive between four waypoints outside my house at a much slower pace than during the 2012 AVC due to the much smaller area and the danger of collision with moving or stationary cars :)

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AVC 2013 info has been posted


Sparkfun has posted rules, walkthrough video, registration for the 2013 AVC.

Both air and ground competitions should be really interesting. The ground course is slightly shorter than previous years, and features fixed, known locations for barrels, the bonus hoop, and the ramp (my robot Data Bus is going to to *love* that feature)

Air competition is primarily over water! And features a wicket hoop thingy to fly under for a bonus, required autonomous takeoff, and a bonus autonomous tennis ball drop.

Scoring is points based with a starting pool of points to which bonus points are added, and time (seconds) is subtracted.

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I was wondering how long it'd be before someone did this... The early stage involves minimal lift capability, but eventually 1000kg -- goods and people.

The MatterNet on FastCompany

Surprisingly "The team's prototype (pictured above) can already do this, but its autonomous capabilities have not yet been tested." -- I would think there are loads of hobby quads that are ahead of this one, then?

I've had dreams of doing this with rovers (of various sizes) of course the issue being the lack of roads... 

Direct link:

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My Robot Magazine Article: Data Bus race rover


I'm very excited to announce that I've been published by Robot Magazine! :)  My article describes the ups and downs of my two year experience building Data Bus, my 25mph race rover, for the 2011 and 2012 Sparkfun AVC (Autonomous Vehicle Competition).

The article appears in the Mar-Apr issue (#39) and sheds light on some of the problems I ran int as well as solutions that worked, and describes some of the adventure -- the thrill of success and crushing blows of failure :)

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2012 Sparkfun AVC - Tobor amazing recovery

My favorite run of the day was Team Tobor. He was having some problems in the first two runs (I can relate) and finally ran a spectacular race in the 3rd run. 


Just at the start, Viator (I think) and Minuteman tangle up in a wreck, but Tobor escapes, heads for the curb, and follows it brilliantly, making a perfect turn through the barrels.

Though missing the hoop, Tobor's buggy rounded the second and third turns. There's a giant pothole on the northwest corner of the building just before the 4th turn...

Tobor went right into it... crashed, rolled... and kept going! The GPS unit flew off the vehicle... but Tobor continued on, made the 4th turn, headed right for the finish, crossed it, flipped... posting the 3rd best time of the day up to that run.  

Seriously-- robot loses a primary sensor but still finishes. Now that is some crazy robust software. Scott's got a nicely set up Extended Kalman Filter pulling data from many sources to estimate heading and position. Really amazing!


So far the only video I've found is this:


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Bot Thoughts / Data Bus - Sparkfun AVC 2012


I had a heck of a time pulling it together in the final days before the competition with a nerve-wrecking mix of failure and triumph. Ah good times! :D

Summary is... I kept running into troubles with heading estimation and heading control in the days prior and things were looking mighty grim. I implemented a few changes and Thursday night went down to SFE for covert, cover-of-darkness testing. To my elation, the fixes worked beautifully and the robot consistently held to its path at faster and faster speeds. I quit while I was ahead with a top speed of 9m/s and time around the building of about 36 seconds.


On Saturday I was feeling pretty good about things, but nervous as all get-out. To my horror, on the first run, the robot did an exact repeat of its embarrasing 2011 performance: it veered right and crashed into the SFE building! I implemented a "fix" for heat 2, discovered a problem with one of the wheel encoders, hammered the front bumper back into shape, and... the robot took off, turned left and headed for the crowd! What a disappointment after the towering success I had Thursday night. I undid my "fix", took the advice of a wiser soul than me (Team Daisy Chain, Ted), and ran the robot slow off the ramp and put the hammer down after a second... I sacrificed myself to save my robot...


And was overjoyed to witness the little bus shoot out from the 4th turn, head for the finish line at top speed and ...


I was just happy the thing finally made it around like it did before. Then in addition to proffering of medical supplies for my ankle, I was informed Data Bus time put it ... in 3rd place! I would've danced up and down... but for the ankle :D  Very very happy. 


Congrats to team 0x27 for 1st, team Minuteman for 2nd not to mention brilliant MacGuyver style repair action! And congrats to all who competed: no small feat, whether your robot started up, crashed, finished, whatever. And humongo kudos to Sparkfun for a truly awesome event, best every by far!



Data Bus37.1637.16
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