Older blog entries for jkkroll (starting at number 37)

Mazetrix Update

I received the pcbs for Mazetrix and started the build. After 4 1/2 hours of troubleshooting I realized that I connected the SCK line to the wrong pin and finally managed to get AVR Studio to recognize the processor. Then I wrote enough code to verify the LEDs would all light up.  However I then started having problems with the firmware. Finally, during my 15 minute lunch today, I found the problem was the fuse settings in the ATMEGA128 (either 103 comaptibility mode or JTAG enabled).

I just added the 3-axis accelerometer, but haven’t soldered on the supporting components. Also I still need to add the Li-Po charge IC. I am currently using the STK500 both to power and program the board.

So without further ado, here are some pics…

Mazetrix project

Mazetrix project

Mazetrix Bottom

Mazetrix Bottom

Mazetrix Top

Mazetrix Top

Syndicated 2009-06-23 02:01:14 from robotguy.net/Blog

Welcome to the Mazetrix

So, I just got an email from BatchPCB that my board has been shipped, so it looks like I’m switching gears again.

My board is for a project based on the Tiletoy, and incidentally not unlike the Space Invaders Button, the Awesome and 64Pixels.

Many moons ago I managed to score several 8×64 Red-Green matrix displays salvaged, evidently, from a casino display. Even though I had managed to reverse engineer them and figure out how to display nifty messages, they were just too large and too COTS for me. I removed the 8×8 LED matrices (matrixes?) and designed a small board to run them. The display is run directly from an ATMega128, using a half-H bridge on each column so I can use the entire matrix as a sensor. Additionally, I have added a MMA7260 triple axis accelerometer. Last but not least is an IR LED pointed in each of the cardinal directions, also connected to be used as an input and an output, for communicating to neighbor modules(PDF link).

The ultimate goal is to create tiles with a red maze and a green “ball” than you can manipulate by tilting, just like the good old labyrinth game. When you get to the edge of a tile, you can connect another, which will attach magnetically, and the maze will continue on the new tile.

I’ll add more updates when I start building.

Here’s a few images to satisfy the curious:



Mazetrix Layout

Mazetrix Layout

Syndicated 2009-06-18 04:55:24 from robotguy.net/Blog

Item 1 – I/O

Sufficient output to be “interesting”

  • Motors – move, dance, wiggle
  • Audio – At least beeps and boops,  possibly recorded audio, but no extra audio hardware (like mp3 decoders)
  • RGB LED Eyes – Maybe even moveable (if I have extra time on my hands)

Sufficient input to be interactive

  • Location sensing – using dual color sensors and a colored mat
  • Light sensors – need to know when it’s dark out, follow a light or find a dark corner
  • IR obstacle detection – don’t want to bump into stuff
  • IR homing sensor – to find the recharge station
  • Hall Effect Sensors – locate and play with toys
  • Capacitive touch sensing – how else is it going to know when it’s being petted?

Syndicated 2009-06-17 05:06:36 from robotguy.net/Blog

Design Goals for Deskpet

I have decided to limit myself to 3 projects; Deskpet, Tiletoy and notebooks. I just built some notebooks, and my Tiletoy PCB is on the way (maybe more about that later), so I’d like to get back to Deskpet.

Deskpet is a project that I am working on to create a small robot to live on my desk as a pet. One of the things I have learned at work is that it is much harder to build something if you don’t know exactly what it is supposed to do. So here goes; high level design goals for Deskpet:

  1. The major goal for the Deskpet is to construct a pet. It needs to live on my desk and generate an emotional attachment.
    • Sufficient output to be “interesting” – If all it has is a pair of motors, I can make it dance, but it would be much easier to generate an emotional attachment if it has other methods of expressing itself.
    • Sufficient input to be interactive – I want to be able to play with my pet, so it needs to be able to sense it’s surroundings, toys and possibly me.
  2. Automatic recharge – If it is going to seem alive, I can’t keep having to put it on the charger.
  3. Wireless communication and bootloading – This is going to require A LOT of firmware work on my part, so it ould be easiest if I could download new firmware without even toucing the ‘bot.
  4. I will not be concerning myself with availablilty or cost of components with respect to eventually making kits available. This will be a project for me.

Well, that should be enough to keep me busy……..

Syndicated 2009-06-15 04:25:03 from robotguy.net/Blog

Testing 1.2.3

It’s not dead! Close call, I thought the blog database was gone or corrupted.

But not very live either. Massive problems with HTTP 500 errors.

OK. Re-installed and looks OK for now. Upgrade from 2.02 to 2.8 deserves a new theme. Maybe something with widgets?

Back to robotics…

Syndicated 2009-06-13 04:15:02 from robotguy.net/Blog

Laser Cat Toy

Stuff like this usually generates the reaction “You have too much time on your hands…”

I was working on my pan & tilt for a Defconbot (defconbots.org) when I realized it would make a great cat toy. A PC is controlling the P&T, running a random pattern with the laser pointer.

Syndicated 2009-02-04 17:34:48 from robotguy.net/Blog

Want to find your ideas in a year? Write them down!

I’ve been a big proponent of keeping my ideas, schematics, drawings, etc. in a lab notebook for years now. I’ve even started putting my notebook online. My current preference is for Moleskine notebooks, but the folks over at the Black Cover blog are convincing me that there are other alternatives out there. They specialize in reviews of pocket-sized notebooks, preferably with black covers. My favorite kind!

Want something more official (and expensive)? Try one from Scientific Notebook Company.

If you are looking for something more robot-related try the Makers Notebook. It includes squared pages as well as an appendix with resistor codes and all kinds of other useful information.

Finally for the ultimate in customization: Make your own notebook. I call mine Myleskine.


The one pictured is covered in “pleather” recycled from a freebie portfolio. I recently made one for my wife with a cover made of hot pink Cordura. Also a pocket size version covered in black 300 denier ballistic nylon is undergoing “stress testing” in the back pocket of another engineer at work. So far it is holding up very well.

Syndicated 2008-10-15 22:37:47 from robotguy.net/Blog

I got the wireless key-fob working:

Family and friends have been having a lot of fun driving it around.

My end goal is to let the ‘bot talk to a base station connected to a PC. I REALLY want to write an RF bootloader, so I can reprogram without touching the ‘bot. This is the hardware for the base station ( Still need to write the software and firmware):

Syndicated 2008-06-19 20:18:05 from robotguy.net/Blog

Deskpet pre-proto

I ordered a Nordic-FOB from Sparkfun to make the coding for the wireless module easier. While I’m waiting, I decided to hack together a pre-prototype of the deskpet using a Baby Orangutan from Pololu, that has an ATMega168 and an LB1836M, the same motor driver that the real board will use. If you want one of those Baby-O’s, get it quick, because they upgraded the motor controller on it, and the old version is going fast. On a good note, they added the LB1836M to their IC page for me, so they should be much easier to get now.

Here’s a pic of the prototype:

P.S. If you are looking for a cool off-the shelf ‘bot, the 3pi from Pololu looks really nifty. Can’t wait until it comes out…

Syndicated 2008-06-17 15:04:36 from robotguy.net/Blog

Deskpet Update & Pics

I finished laying out the PCB during lunch today. Maybe I can clean it up and get it out to BatchPCB for fab by tomorrow morning:

I finally got around to taking some pictures of the base:

Syndicated 2008-06-11 04:26:20 from robotguy.net/Blog

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