PIC based LEGO controller 6-aug-2002

• Motor control: A BA6286 Reversible motor driver (integrated H-bridge) controls 1 motor via 2 inputs: "Forward, reverse, brake and free running". Output to the motor is the power supply voltage (9.6 volts when running on batteries).
• Crystal: 14.7456 mhz
• PIC: PIC-16F876 processor from Microchip
• Buffer: HEF40244 octal buffer
• Power: 9.6 V input from 8 1.2V NiMH batteries or 12V from a net adaptor is converted to 5V using a LM7805 voltage regulator. A 100uF capacitor helps keeping the power supply from the batteries constant.
• Serial prg: In-circuit serial programming of the PIC via a pretty simple circuit of resistors and diodes. The switch switches between programming mode and run mode.
• Test: 1 pin from the PIC is connected to this circuit, which can either control a LED (output) or read a switch (input).