This is based on HF5L Club work, as it’s hard to find (and expensive) a 23cm SWR/Power meter,

“A dual meter would be much more convenient for measuring the standing wave ratio (SWR) and return loss. Reinhardt DC5ZM also developed dual meter using two modules with AD8318.”

this use two -40db coupler from China, sketch has been recoded to match atmega328P, with two digital buttons, and I2C display 2×16, the goal is to measure some watt’s, not miliwatt with this unit.