The IQaudio Codec Zero is a Raspberry Pi Zero-sized audio I/O HAT. It delivers bi-directional digital audio signals (I2S) between Raspberry Pi Zero and its onboard Dialog Semiconductor DA7212 codec. Codec Zero supports a range of input and output devices, from the built-in MEMS microphone to external mono electret microphones and 1.2W, 8Ω mono speakers. The IQaudio Codec Zero has green and red LEDs that can be used for status, and a tactile button that can be used to start an event. Codec Zero makes a great starting point for a walkie talkie, intelligent doorbell, vintage radio hack, or smart speaker.