If you have an idea for something awesome that a Cellbot could do, or need help with building your own robot, the new discussion and support group is for you!
http://groups.google.com/group/cellbots
Start a conversation today, share your projects, or rant about your Cellbot not doing the dishes when you ask it to. All topics on robotics are welcome!
TRRSTAN kit Contents
The TRRSTAN kit is designed to meet three main goals:
The physical design of TRRSTAN uses the PCB as the chassis, CDs for drive wheels, and nylon shower door rollers for rear wheels. This gives it an overall look similar to a roman chariot. Smartphone jousting anyone? CDs wheels were chosen so they could be made from CDR coasters or unwanted Hana Montana albums. The large diameter makes it a pretty fast bot. The phone is held on with rubber coated screws and an optional Velcro strap.
The electrical design of TRRSTAN has two main circuits. For power their is a TI boost/buck regulator that accepts from .8V to 6.5V and provides a constant 5v at up to 1500mA, depending on how far it has to boost. It also provides a low battery led and overheat/short protection. It is supplemented by a low VF Shockley Diode, which provides up to 3A directly from the battery if the 5V line drops due to high start-up loads. The kit currently ships with two AA batteries and a holder, which keeps cost low.
The second circuit controls the servos via the audio. The software on the phone generates a pulse width modulated signal that travels to the board via a standard 3.5mm TRRS(tip-ring-ring-sleeve) headphone+mic cord. Then a Toshiba quad opto-coupler to rectifies the +- pulse of the audio signal, boosts it to 5v and squares it off. With some servos you do not even need the boost from the opto, you can drive them directly from the headphone cord. However, the opto also provides electrical isolation to protect the phone if something bad happens.
TRRSTAN Schematic
There is also space on the board for a sensor upgrade kit that allows two 0-5v sensors, two quadrature encoders, two bump switches, and sends data back to the phone via the mic line. This sensor upgrade kit does use an 8pin AtTiny13. This upgrade kit is still in development.
Ready To Rock
TRRSTAN, along with some other Cellbots, will be at the Maker Mini Faire in Denver Colorado, this Sat, July 17
If you want to drive a cellbot come on down. We have a special treat for drivers.
If you have been thinking about building your own Cellbot, the barrier to entry just got even lower.
Introducing TRRSTAN, the audio controlled Cellbot:
TRRSTAN is now for sale on the inventor’s site: robots.allthingsgeek.com
Truckbots are still available at the cellbots store.
Look for a full post explaining how TRRSTAN works soon.
We’re thrilled to be demoing our Android Cellbots at the 2010 Intel International Science & Engineering Fair this week in San Jose, California. Thousands of people will be dropping by the Google booth to play with four of the robots and learn how they work. The kids are having a blast and the parents are jealous they couldn’t do things like this at their age.
We have some video streaming from the phones to the big screen TV and people can also use the remote to trigger still pictures to be snapped. The demo shows off the use of Android Nexus One phones as remote controls using the accelerometer to drive the robots. That sends XMPP commands over Google Chat to another Nexus One on the robot, which act as the main brain. That phone then sends commands over Bluetooth to the robot hardware.
We hope the excitement continues and we see more kids making Cellbots this summer. Our parts lists for the Android robots and the source code project site can help you get started. Those short on time can also check out our robot kits page where we can put together a package for you. Then be sure to jump in on the discussion list to ask questions and share news of your projects!
Getting this demo ready was a big team effort that took a lot of work to go from short five minute demos to having four robots run all day for a week. Damon Kohler came through with awesome upgrades to last week’s Android Scripting Environment. Charles Chen was extremely helpful in getting the video and still image streaming setup, and used some code from Darrell Taylor’s work. Jason Holt, maker of the Boxbot, helped with the remote control mathematics and getting the demo table ready. Tim Heath upgraded the kits page for those of you interested in using one of our designs, and Glen Arrowsmith’s recent Arduino code that saved calibration data to the EEPROM was critical. Many thanks to you all!
If you are in the San Jose area this week, be sure to stop by the convention center on Thursday May 13, when the International Science and Engineering Fair is open to the public from 9am to 9pm.
We’ve simplified the Tankbot so much that this has to be one of the simplest and cheapest robots around. Instead of a 5v Arduino, which needs 3.3v to 5v logic level converting, we’re using a 3.3v Arduino Mini Pro. The TX and RX pins can connect directly into the HTC breakout board on the bottom of the Android G1 for serial communication.
The only tricky part was getting a thin 30 gauge wire to run into the back of the phone and wrap around the positive battery terminal. We tried some thicker wire at first but it prevented the phone from maintaining a connection and it would shut off accidentally. The thinner wire sits there nicely and we might try making a permanent connector on the outside of the phone so it can fit back in a pocket without a wire sticking out.
The top picture is a working version with the red 30 gauge wires above is an early test with a thicker green wire that had a flaky connection. You can see that we’re still using the HTC breakout board wiring for TX, RX, and ground, and we’re not yet connecting the fourth wire that you see here. That would be used for charing the phone but doesn’t provide enough power out to run the robot.
This video overview shows you the whole thing moving around to prove it works. No word yet on the effects of doing this on your battery so please do so at your own risk.
If you get something similar working, share it in the Cellbots support & discussion group. Bonus points if you hook your robot up to a wireless charging station!
