Let's Make Robots!

JAX's blog

BoB the Biped and Me: BoB finally gets his lights.

Finally got viable PCBs for the LED array. Even still I burned up two out of three of the boards and several microcontrollers with various mistakes but the last one was a winner.

Front and back:


Shout Box talking RPi: Trials and tribulations

A nice perk of LMR is the Shout Box, LMR's own little chat room. Many times I've been struck by motivation to solder/etch/hotglue/bodge something just through the good maker-mind energy in the SB but, alas, I would have to hang up the phone, if you will, if I were to head to the workbench. "Gee," I thought, "wouldn't it be awesome to have the Shout Box read to me so I can laugh and cry and work on a project all at once?" Yes, and it is awesome.

BoB the Biped and Me: Asthetics phase complete

When the long awaited Rev. B PCBs arrived it didn't take long to realize I'd mucked things up again. I'd forgotten to connect any of the I2C lines. So now I'm waiting for Rev. C which is back from fab and will soon be sent to me.

So instead of working on that I set out on wrapping up some finishing touches on BoB's outfit. I found a lot of good things to add recently. One thing I found was some Stikfas Cuboyd robot toys:

Within moments of receving them...

BoB the Biped and Me: BoB gets a 'hawk, naturally.

In general news: The Rev. B boards have been taking a tour of San Diego. Looking at the ZIP codes provided by the tracking info says they're getting closer. They might even be here tomorrow, who knows.

So with that nonsense going on I figured I might as well dig into fleshing out ole BoB here. I wanted to add more team spirit and I thought getting hair in a Mohawk style was a no-brainer, right? And in team colors, with the more modern team pallete using darker blue and neon green:

BoB the Biped and Me: Tested, approved, and waiting for Rev. B PCBs. First vid with chickenparmi's sweet LMR bumper :D

BoB's edge detectors worked fine at home but in his operating environment at a bar he was failing miserably. There were many false edge detections while walking over safe ground. The high gloss surface of the bar was reflecting light under his feet during even the slightest wobble when he put down his feet (the point where the edge sensors were read). This led to him backing up into hazards I was trying to avoid.

BoB the Biped and Me: Edge detection vid and fun assembly vid (updated)

After spending a good deal of time working on a couple of BoB's subassemblies I've been given some time to think more about how to use those extra headers on the circuit board. I really want bump detection, edge detection, and a speaker but I know only one or two of those are going to fit inside the chassis. After letting BoB wander around on the floor at length I realized how prone he is to toppling over. That plus the fact he will be spending time on a bar, where sinks full of water lurk below, I decided to work on the edge detection.

BoB the Biped and Me: LEDs, camera, action! (updated)

I finally got a quartet of routines that produce pleasing lighting effects out of BoB's toothless grin. Using CYZ-RGB LED pixels for hardware. If you have any other ideas for light sequences I'd love to hear them, please.

edit - July 14th, 2013

Added test code slightly different that what is seen in the video but essentially the same.

LU2MI2 build log: July 11th, 2013

As noted elsewhere I had to start something new to add updates to this project and from now on it will be in the form of blogs (it's about time, huh!). To summarize the project's status, things were going well until I went to test all the subsystems together on the actual chassis. I had forgotten to breadboard test the 3.7g servo at the 3.3V I was going to supply it with and it turns out it hated it.

BoB the Biped and Me: We celebrate the Seahawks! (updated)

Just a place to put a link to the video of BoB dancing while I applaud. I'll update with more info in the future. Gotta meet my buddy at the pub in a few minutes, hence the brevity.

There are four total dance moves, I think the video only caught three of them (they're randomized).

Update: July, 14th, 2013-

A schematic of of the detection circuit:


BoB the Biped and me: We love quiet sunset walks on the beach.

This is just a happy blog about how my BoB is fully mobile and can navigate obstacles. The sensor is just hanging loose but if angled the right way it works fine :) I'm using an HC-SR04 sensor with the newping library for fast distance readings that don't put a big hitch in the smooth walking. I have the library set to timeout the sensor if there is no signal after about a foot or so. Distance readings are only taken while BoB is facing forwards, be it on one or both legs.

BoB the Biped with his Arduino motor cortex

After a lot of reading and some minor language barriers I've finally gotten over my fear of Arduinos. Thank you, BoB. He was in need of some floating point math so it seemed like a good time to make the transition. I find what I write looks a lot like BASIC but I'm just glad it works.

BoB the Biped and me with v0.91 board design

I got my pile of BoB parts from isotope yesterday and I was stoked to say the least. He even printed out a JAX name badge for me \o/ Thanks man! My BoB is glow-in-the-dark blue ABS and it luminesces as advertised. Blue Glowy BoB... mmm.

Initial test fits showed that there was going to be some grinding work in my future to make things work. One change I made to the original build list was using an HC-SR04 for the sensor. The sensor holes in the head were too close together so I removed some material on the outer edges to make it fit. It's real nice now.

SOMO 14D (WTV020-SD-16P) and MDfly MOL-AU5121 (Tenda TDB380) sound module comparison

The 4D System's SOMO-4D and the MDfly AU5121S are sound playback modules that allow you to add audio to your projects. I've used both and find both are excellent in terms of sound quality vs. price point. Each one is slightly different and has their good and bad points. I will attempt to give the reader a summary of each and provide information that I had to travel the web for to compile myself. Although anyone can find the same info I thought it handy to provide it in one tidy place.

UV Fluorescence marking - initial concept fail

I've done a bit of initial feasability testing for this project. Last week I used the four 50mcd UV LEDs and two 630nm detection LEDs. The signal generated from the op-amp was around 0.15V. Background noise was measured at about 0.05V. 

I've since received the 2000mcd UV LEDs, and wow, are they bright! They also don't blind the detector LEDs during direct exposure. The less powerful 50mcd LEDs would.

A picture of one of the longer distance test setups:

Babblebot USB board speech demo and update

A listen to some speech coming from my Babblebot USB board talking to a PICAXE 14M2. First it croaks out the allophones in sequential order via its "demo mode." Then I have it repeat a phrase with different register changes.

Territory marking through UV fluorescence

For awhile now I've been considering ways to have robots tag an area for other robots to detect in a way that wasn't readily apparent to the human senses. The application would be for my outdoor solar swarm bots. They would use the marker to signal to other robots that "this is a sunny location in the morning." I wanted something passive, no electronics. No dropping off a bunch of miniature IR beacons around my patio or any such thing. Hmm.

Babblebot USB board works, sort of

I purchased one of these voice synthesis chips as kind of a knee-jerk reaction to Maxhirez's bot but I didn't know that they were so finicky and questionably documented. It seems the nature of breadboards cause a lot of problems with this chip as well, some of which I am very familiar with. With the challenges presented it seemed best to design my own PCB and have the pro's through Dorkbot fab the board. I would have considered buying the dev board from the Babblebot guys themselves but it only comes in RS232 flavor!

LMRbot WS2 - Progress made, progress halted

Since the last blog (Applying Murphy) I did all my tricks and other people's tricks but none of them solved the servo jitter problem. What did work in the end was removing all I2C communications. After that my bot happily tracked me as I celebrated the return of some kind of functionality. After some careful consideration I was able to pile the 18M2+20X2 setup into one almost-maxed-out 20X2. Without the need to slave the 20X2 (paired with the problems I'm having), the attractiveness of two-wire I2C communication disappeared.

LMRbot WS2 Edition - Applying Murphy's Law

Dismay. Chagrin. I'm bummed out, man. Failure to meet three deadlines. Well, two really, because the one got postponed. Regardless, this bot has run out of time again. I was making good progress, totally on my way to having a submission for the Make character bot contest. Most of the hardcore fabrication of the bot itself had gone by with only a few mad hatter moments. All subsystems had passed the proof-of-concept tests. I was making progress at an unprecidented rate. That was up until late, late, late last night.

Mental vomit from an intoxicated robo-teer


My girlfriend successfully took me out and outdrank me tonight. Forget what that says about my manhood, here I am with something to say :hiccup: :)

LMRbot WS2 Edition

UPDATE: Jan. 21, 2012

FIRST Robotics Competition '11 Regionals, San Diego, CA - part 5: Finals and Duckie Damsels

My final installment for this series. I didn't stay to the end but I caught a couple of the final matches and got a souvenier for the memories.

Vid 1: The intros to one of the matches. I think they were waiting for the third red member to arrive so I stopped the camera. When the bot arrived, crew dragging it onto the field frantically, the crowd went crazy. It had no claw, no mini-bot, nothing. A pure defense bot. It was the talk of the pits.

FIRST Robotics Competition '11 Regionals, San Diego, CA - part 4: Pits of interest 2

Vid 1: Steve from The Daedelus Project had encountered some problems with their four motors synchronizing correctly. He spent a moment telling me about the problem and quick fix that got them through the competition.

Note - I get sideways with the shot early on but quickly remember I'm shooting video. One time only, I promise. And I had no idea my hand position makes such a dramatic difference on sound quality. Apologies for the ignorance.

Vid 2: The bot from Tecnológico de Monterrey campus León waved me over. Almost literally.

FIRST Robotics Competition '11 Regionals, San Diego, CA - part 3: Pits of interest 1

A couple closer looks at some of the groups that intrigued me.

Vid 1: High Rollers had a cool internal conveyor belt setup inside their gripper.

Vid 2: Eagle Robotic's gripper had a version using rubber bands to manipulate the grip angle of the inflateable.

Vid 3: Team Spyder had a gripper outfitted with roller blade wheels (motorized?) and a minibot for the extra points.

Vid 4: A member of the Atascadero Greybots is proud to talk about their gripper design.

FIRST Robotics Competition '11 Regionals, San Diego, CA - part 2: In the pits

After watching some action I decided to take a look at the pits. There seemed to be three (main) things that set the team's robots apart from one another: Its gripper (or lack thereof), its mini-bot (or lack thereof), and if it was autonomous or not. The first 15 seconds are programming only; no human interaction. A chance for bonus points awarded to ingenuity. After that there is a human driver controlling the bot. They also have to deal with the robot's design flaws/design superiority when it came to lining up with a tower to deliver the mini climbing robot.

FIRST Robotics Competition '11 Regionals, San Diego, CA - part 1

Even though I had some serious hot glue and coding to be done at my own workshop I checked out the final day for the FIRST competition. I didn't have much expectation for the event. Not to poo-poo the under-21 crowd (otherwise I wouldn't have gone) but I had no idea that robotics had a following I was completely unaware of. My surface skimming of the FIRST's website didn't hint at how big a production it was. I was pleasantly surprised.

Peltier Pal project


This project hit several roadblocks. I'm still not sure how to address some of them.

PICAXE IR sensor debugging music!

I decided to harvest a peizo buzzer off one of my many salvage boards to use while troubleshooting a new IR reflective breakout per Frits' description in Live Show #012. It works like a machine. I only fried one sensor (hasty connection straight to V+). Surface mount components are easy to replace though, thank The Maker. The video has everything but the sensor carnage.

Ahh, sound debugging \o/  I think I've entered my personal Golden Age of Robotics.  

QLF6 Totem Pole project (Step 1: DIY PCBs)

I've been tinkering on this blinky light project for awhile, almost a year now. I finally got around to etching the all-critical prototype PCB today. Maybe I can finally get this show back on the road. It will be a totem pole of sorts that runs like a solar powered garden light utilizing four independent QLF6 (or Quad LED Flasher v6.0) circuits.