Using Inter Integrated Circuit and HWlib to communicate with a PCF8574. The goal is to get a better understanding of I2C and the PCF8574 for future exercises.
It's a finite state machine resembling a tamagotchi that's happy when it's standing up and he has company. Consequently, a tilt sensor and RCWL-0516 Radar Sensor (based on the Doppler Effect) are used. It beeps when it's not happy using a Passive Buzzer. Check it out here.
The entire circuit is so large because of the requirement to use logic gates... However, it's very fun and a huge relief if it actually works.