The AK-MAX9814 is a board with a microphone and a high-gain amplifier with AGC.
User manual for the Artekit AK-3232 and AK-3232L level converters.
User manual for the Artekit AK-USB-RS485-FD, a full-duplex USB to RS485/422 bridge.
User manual for the Artekit AK-USB-RS485-HD, USB to RS485/422 bridge.
This guide covers the Artekit AK-4XRS485/422, a RS485/422 driver, and the connection over a physical network.