This page has information about the EE2101 Robot with stepper motors (Boards are marked as Rev. F).
EE2101 Information
The EE2101 Robot was created for students to have a platform on which class projects and experiments could be built. This is an updated design of the EE152 Robot. The previous design used gear motors and wheels sensors to determine how far the robot had traveled. This version (Rev. F) uses small geared stepper motors. The result is easier to assemble and more accurate in its movements. A different type of software O.S. allows the robot to operate the change the motors and sound independently so the robot can move and generate sound at the same time. The microcontroller used is an Atmel AT89C51RC2 (other 40-pin 8051 based microcontrollers should also work (the software may need to be adjusted for different microcontrollers)). A datasheet for this processor is given below:
Microcontroller Datasheet - Atmel microcontroller AT89C51RC2 http://www.atmel.com/dyn/resources/prod_documents/doc4180.pdf
Port 0 is used to control the stepper motors. This is because the drivers for the motor coils are active high and the external pull-ups for port 0 can have the voltage switched off as a default. This allows a unprogrammed microcontroller to be placed in the circuit and as a default have the motors switched off. The pull-up voltage is controlled by port 2, Bit 7 (P2.7) with a '0' on that pin switching on the pull-up voltage. The rest of port 2 is used to control the seven (7) LEDs of the display. The UART pins (P3.0 and P3.1) are used for In-System Programming. The rest of the port 3 pins are connected to six (6) switches that are used to enter the robot's path. If the switches are not used, then those pins can be used for alternate functions in a user's program. The only pin used on port 1 is bit 4 (P1.4) which is used to control the speaker. It was chosen because I had hoped to use the PWM to control the speaker, but the PWM did not work as I expected it to work so the sound is created using an interrupt function instead. The rest of port 1 is available for a user's program.
This microcontroller is In-System Programmable through the serial port (UART). A programming circuit is built into the robot so that all a student needs is a computer with the download software and a serial cable. The Atmel microcontoller is programmed using FLIP, which can be downloaded from the Atmel website (link: http://www.atmel.com/tools/flip.aspx). The robot also has a built in battery charger which can charge six AA size NiMH batteries when connected to a 15V, 500mA power supply. A few small prototyping areas are built into the robot including two break away boards. The break away boards have mounting holes and there are additional mounting holes on the robot. There are four mounting holes around the battery pack that can be used to mount an additional boards or be used to mount a 7.2V rechargeable battery pack.
The downloads includes versions of the robot software and a schematic for the robot.