This is an Arduino supervisor for a simple Yaesu ATAS-100 / ATAS-120 antenna controller
My Yaesu ATAS-100 died after a decade of exposure to road salt. It mostly completely ate away the aluminum body tube. I replaced the ATAS-100 with an ATAS-120 and fixed the ATAS-100 with a new aluminum body tube.
This antenna works by placing either a +8V or +12V DC bias on the transmit line. +12V makes th antenna extend. +8V makes the antenna retract.
I built a bias tee from the AD5X plans:
http://www.ad5x.com/images/Articles/BiasT3amp.pdf
...only one side is needed for the ATAS controller.
The controller is a simple center-off / momentary SPDT switch for either +12 or a regulated +8. But - I wanted some way to determine if the antenna was at the end of travel or if there was an over-current condition.
Normal current for raise or lower is around 200mA. When the antenna is at the end of travel / stalled, current is around 650mA.
The idea is to use a high-side DC current monitor, an INA219 that reports back via I2C both voltage and current values. A junkbox 1x16 LCD will report back up/down based on voltage and current values.