Jon's Place

Tuesday, May 29, 2007

BrainBot is Hardware-Complete

Wow, talk about reaching milestones. All the bits and pieces are now together, at least for the level I need for doing the demo on Friday.

For the next two days, I will be concentrating on software. The gripper software needs a small update to deal with the wrist sensor, and the overall package needs a little more integration and cleanup. My friend and colleague Julian has been taking care of the Smalltalk side of things, and yesterday we got wifi control of the robot integrated with SYNC_WRITE and SYNC_READ, which allows us to update the position/speed of each actuator in one instruction, and read sensor information from each device on the bus with a second instruction.

Things are coming down to the wire, but I think this thing is going to work really well...

*The BrainBot project is directed and funded by the Brain Engineering Lab and Neukom Institute

Sunday, May 27, 2007

Gripper - Moving

So, after getting yet another PCB for the gripper (revision 3), and getting more help from my brother in the way of PWM code for the AVR, I managed to put together a gripper with a machined gear set, and both motors working. To the right you can see a picture of it, with the board mounted, and almost fully set up. Right now the only things missing are the two sensors - one for the finger pressure, and one for the wrist rotation encoder. I have both sensors, I just need to install them and test them.

Here's a movie (566 KB) showing it in its current form, opening and closing the gripper, and rotating the wrist. It is running a little sample program I wrote for the ATmega168 to test that the hardware works.

*The BrainBot project is directed and funded by the Brain Engineering Lab and Neukom Institute

Thursday, May 24, 2007

BrainBot - Major Milestone

So, tonight I reached a major milestone with BrainBot. For the very first time, I moved a servo, completely untethered. BrainBot is put together now, running Squeak code on the gumstix verdex, accessing the bus over USB directly at 1.0 Mbps, and talking to my PC over wifi (also USB), and running off battery.

With an ssh session into the gumstix (which runs Linux), I was able to start my Squeak image, and it sent the command over the bus to move a servo back and forth.

It may not seem like much on the surface of things, but it represents many weeks of hard work finally coming together. By this time next week, BrainBot will be walking under control of a Squeak image running on my laptop, talking over wifi to the gumstix.

Here's the movie (1.3 MB), if you're interested in seeing it - not all that exciting to watch, but very exciting for what it represents...

*The BrainBot project is directed and funded by the Brain Engineering Lab and Neukom Institute

Thursday, May 17, 2007

Grippers, Version 2

Today I got my new grippers in the mail (eight of them) from my friend John at Xardas in San Diego. As I've come to expect, they look awesome, and the new design touches I put into the model really help when it comes to putting them all together...

The second picture on the left shows the gripper, with the actuator fully mounted, and the first revision gripper PCB.

*The BrainBot project is directed and funded by the Brain Engineering Lab and Neukom Institute

Friday, May 11, 2007

So, John from Xardas (the 3D printer guy) did a couple gears for me on his 3D printer, and they turned out fantastic... I think, given how clean and simple it is, I will just get the gears printed. They come out similar to the machined gears, but it takes much less of my time, and won't add a lot of cost...

*The BrainBot project is directed and funded by the Brain Engineering Lab and Neukom Institute

Wednesday, May 9, 2007

BrainBot Coming Together

So, things are starting to come together - all this being super busy stuff is starting to pay off. BrainBot* is getting close to being functionally complete. There is still a bunch of work to be done, but I'm starting to see the light at the end of the tunnel.

I've got the robot put together, in close to its final form. All the boards are mounted, and a lot of the wiring is done. BrainBot weighs in at a hefty 3.0 kg, so it will be very interesting to see how well the AX-12 servos do under that kind of load.

I have to give a demo at the Brain Engineering Lab in New Hampshire at the end of May, with BrainBot walking and capable of manipulating small objects, with a nice text-mode (URBI) socket server front-end.

With any luck at all, BrainBot will be going on sale as a full-on kit sometime later this year. Imagine being able to buy a research biped that has a pan and tilt stereo vision head, dual two-axis manipulators, a total of 24 degrees of freedom, a high bandwidth wifi interface to a PC, a six axis IMU for balance, and pressure sensitive feet and grippers.

*The BrainBot project is directed and funded by the Brain Engineering Lab and Neukom Institute

Tuesday, May 8, 2007

Foot Pressure Sensor Boards

So, I finally got around to populating one of my new foot pressure sensor boards with components. Once I figured out that my reflow oven controller was lying about what temperature it was reading, I just re-reflowed the board manually, watching for the solder to reflow.

The good news is, it worked fine, and it fits perfectly on the Bioloid foot as well. This board is a protoboard, and I will eventually get "proper" boards made from the same place that did my IMU boards.

*The BrainBot project is directed and funded by the Brain Engineering Lab and Neukom Institute

Monday, May 7, 2007

Too Much Stuff

I've had a couple people comment that I haven't posted anything to my blog in a while (its only been a week)...

So, I thought I would put up a picture of my electronics desktop, just to give an idea of how many things are going on at once here, and the piles of stuff I'm trying to get done:

- BrainBot chest
- IMU
- Gripper
- Foot pressure sensor boards
- USB board for inside BrainBot
- gumstix verdex with wifi and usb

Things are crazy busy right now...