The 4th Annual Colorado Robot Challenge CU Robotics Club

Electrical Systems Signal I/O and power distribution

The Brains of the Outfit CURC decided on a 40 pin AVR Dev board to process the navigation Info and send directions to the Daughter Board, seen on the next slide. This board is wired up and ready to go in our lab. This prototype board houses the 40 pin Atmel ATMega microcontroller. It comes with 10 pin STK ICSP port, RS232 port, reset IC, 8MHz crystal oscillator circuit, status LED, reset IC, and power supply circuit built in.

Daughter Board The Daughter Board was developed to: Relay the sensor inputs Distribute the sensor power House the motor drivers Provide a modular mounting surface for the sensors without directly attaching them to the Dev board. The board is currently in production and will ship the 12th of March.

Programming Systems Signal and movement code

Programming Overview The programming team is now storing code in an SVN repository through the physics department. The control systems are using an interrupt driven design. External interrupt pins 0,1 are used for the touch sensors. Using 1 16 bit timer for delay functions (times > 31 ms) Using 1 8 bit timer for smaller delays ( time <=31 ms) Overall code design Poll the IR and compass modules while waiting for timer interrupts to fire. Once we have a beacon update move the robot to the correct heading and set the movement timer. Interrupt exits and we go back to polling We have 1 large timer that handles getting a beacon update (think once every 30 seconds or such) Biggest issue is going to be interfacing with different sensors (compass module uses I2C, IR is straight analog signals. )

Mechanical Systems Chassis design and component layout

Chassis Concept Seen to the right is the design for our current prototype chassis. It is two aluminum plates connected with a pivot assembly. The pivot allows for maneuverability over rough terrain without the added weight of a complicated suspension system. The wheels we have in mine are sand tires made for RC cars. Electronic Systems will be mounted on one of the two sides.

Pivot Assembly Our Mechanical Lead has designed a pivot assembly the aid with rough terrain. The pivot connects the two halves of the chassis and limits the amount of amount of rotation . Fabrication of this assembly is completed and ready to mount.