I tried smartHomeHub/SmartIR, but the codes of Hitachi AC is not so match, and Broadlink has a code set (match most Hitachi) works good for me. So I extract the codes, details here Hitachi_IR_Code.
My AC do not has a “status monitor”, so I have not test all the commands. I just know it works, but no feedback (just status light color).
If you have a Hitachi AC, and willing to help test, put the 1804.json into .homeassistant\custom_components\smartir\codes\climate\, and change device_code: 1084 in “smartir”, restart HA, and have a try.