Sunday, June 14, 2009

C# "Software Joystick"

We've hacked together a C# program that writes motor commands like #+20-15; (motor 1 200 forward, motor 2 150 reverse). The serial port has Xbee connected to it. The only tricky part was the motor equations below.
double radians = Math.Atan2(dy, dx);radians = radians + Math.PI / 2;
m1 = (int)(Math.Abs(dx) * Math.Sin(radians) + Math.Abs(dy) * Math.Cos(radians));
m2 = (int)(Math.Abs(dy) * Math.Cos(radians) - Math.Abs(dx) * Math.Sin(radians));
(Equations from David "Wild Shot")
(ps: Its a Visual Studio 2005 project - We can post a copy once its been cleaned up.)

Wednesday, June 10, 2009

The Prototype "LV Tanker"

The first prototype with working Arduino, Adafruit motor shield, XBee, XBee adapter, motor power pack and 9V Arduino power, plus the Arduino sketch and Windows controlling program. The first try was buggy but working. Update: It turns out that the rechargeable power pack (from a swiffer) used to run the 2 DC motors was overheating the H-bridge on the motor shield. After switching to 4 AA batteries everything ran smoothly and we were able to drive it around the house.

XBee Adapter Kit

Making the XBee adapter ... about 1/2 done. After configuring with a TTL cable and testing the XBee adapter, the motor shield and the XBee adapter (both from Adafruit) were easy to get working together. (We were able to get analog pins 14-19 working fine as digital pins but could not get NewSoftSerial to read more then 2 chars in a row without errors so we went back to pins 0 and 1).

Thursday, June 4, 2009

Fabricating parts

We have made 6 aluminum axils that are attached with nylon chain and turn in brass bushings. We are using nylon, aluminum and Lexan polycarbonate sheet to keep the weight down.