https://froghilllabs.com/Articles from Frog Hill Labs projects and experiments.https://froghilllabs.com/articles/taking-mitsubishi-mini-splits-local-with-cn105/https://froghilllabs.com/articles/taking-mitsubishi-mini-splits-local-with-cn105/Thu, 30 Jul 2026 00:00:00 GMTHow I built two local, bidirectional ESPHome controllers for Mitsubishi MSZ-FH12NA mini-splits—and discovered 12.48 volts on a connector pin commonly documented as unused.