I am almost done with firmware for MABMPU simple controller. This is a potential replacement for DRO levels that can be expanded in the future to work with various popular EME trackers like RazTrak, DrzTrack, OE5JFL, F1EHN. In order to use this setup, one MABMPU encoder board takes on role of the controller and reads the US Digital SEI bus encoders and displays the results on the LCD. This simple controller works with US Digital A2 and A2T encoders or MABMPU encoder board (using MAB25, MAB28, ETS25 or MPU9150 inclinometer). Power (+12VDC) is provided to the encoders over the 6-wire CAT-3 cable from the MABMPU simple controller. In theory, the US Digital SEI bus can drive cables over 100m. For those that already have a EME tracker which utilizes US Digital encoders, I have a version of the MABMPU LCD firmware that monitors the SEI encoder bus for encoder read position commands and simply displays the positions on the LCD display. In this configuration, the power to the MABMPU monitor is obtained from the SEI 6-wire bus. Simple Controller: https://www.dropbox.com/sh/967cur8w88zrtgh/AAA5N_CrlFZpQsHmjIBwP2vaa?dl=0 More photos: https://www.dropbox.com/sh/8h6cp0hw463rekc/AACK_Lv0Nswr_P0mWGIDkwoLa?dl=0 Gary, N8CQ