GGHC Schematics

Here are the latest versions of the schematics for the devices we plan to make as part of the GGHC:

Student Schematic

The student unit:

Some key features of the schematic:

• LEDs for answers are optional: the switches can be used alone as inputs
• 7-segment display driven by shift register

Student Schematic

The teacher's unit:

Some key features of the schematic:

• Uses crystal oscillator for microcontroller
• LEDs for answers are driven by input switches, not microcontroller (required to save output pins)
• LEDs for answers are optional: the switches can be used alone as inputs
• 7-segment display anodes are driven by timer compare outputs for multiplexing without software
• Mini-USB port with level-matching components