Looking to control a heat-pump with a Pi0w. The heat-pump supports 5V TTL control and provides a 5-pin connector with 5V/12V/GND/TX/RX. The 5V/GND can be used to power the Pi directly. It seems like the bi-di logic level converter (12009) can be used to convert the heat-pump TX/RX to the 3.3V required by the Pi RX/TX. Would this require the HV/LV/GNDs on the 12009 to all be connected to the Pi’s 5V/3.3V/GND?
The grounds are tied together on the board so you only need to connect one of them but you do need to connect HV and LV connected to their respected voltages for the board to operate.
Thanks, Chris. Any issues feeding HV and LV on the 12009 from the Pi even if the source 5V is from the heat-pump?
That should be fine.
Thanks!