Dual Core Arduino Known as Core2duino

The goal of the project is to create more I/O pins by adding another ATmega168/328 on top of an Arduino.

This Arduino shield can provide an extra complete set of I/O pins to use for a total of 40 digital pins al or 12 PWM pins, 12 analog pins, and 4 external interrupts. A completely separate CPU can be added to the project that is unaffected by any code running on the base Arduino. Two external interrupts are used by the base processor to sample and decode 2 servo signals from an R/C transmitter/receiver. A relay is controlled for the motor-controller power supply as a 3rd servo signal is sent to the Core2duino. The Core2duino can still carry out its main function unaffected even if there is a problem with the main code and it stops responding.

The stacking feature allows excluding the power supply and USB interface which does not require building a complete Arduino board. The communication between the two Arduino is through I2C interface which only consumes 2 digital pins using ports 4 and 5. the access to the base Arduino is provided by a breakout board for ATmega168.

Rest of the project