The ServoTank platform was bought from Budget Robotics about 2005 (no longer in production).
Dealing with multiple voltage levels. The Bot-Cop-DODICI design, with on-board voltage dividers and selectable buss voltages on the digital, analog and I2C expansion headers, makes it easy to configure the board to deal with different input-voltage levels and both 3.3V and 5V devices. At this point in time, many older devices use 5V power, while many newer devices use 3.3V. The ServoTank uses the following voltage levels:
On the ServoTank, Vdd is set to 3.3V for the ATmega, mainly since the only power to the board is from the servo battery (6-7.2V), and use of both 5V and 3.3V regulators in series provides more noise-filtering on the Vdd buss. Input voltages from external devices to the ATmega were lowered to the 3.3V range by selecting the voltage-divider ratios on the expansion headers.
Many Arduino sketches were written specifically to test the Bot-Cop-DODICI board and also to serve as templates for use in other applications besides the ServoTank.
Source code for Arduino sketches: