From the amazon customer pictures, it looks to me like the lift is being driven by simulating the PB in the lift control using an ESP32 controller. Like # 3 below.
Update: after looking at other offers of the lift on amazon it looks like the control panel is separate from the controller. Therefore I think this hack I think the control panel was replaced with an arduino+relay module to simulate the panel.
I would start by finding out how the motors and sensors in the unit are wired and draw a schematic of the units interface with the controller. It will be interesting to see if the unit has end stop sensors.
Also, open the controller and find out if you can get to the up/down functions initiated at the control panel.
Update: This may require finding out how the control panel is wired to the controller.
A user manual will tell us how the up/down functions work.
Then you can decide how to interface with the unit.
1. Hack the existing controller: if you can get to the up/down control (PB) this may be the easiest way. You can simulate PB contacts closing with the inching function on the wifi relay module. This lets the controller do all the motor and end-stop management.
2. Build your own open-loop Google Home compatible controller:
There are many inching controllers (timed relay) that can be configured to turn on a motor for a period of time [modules like you already have]. This assumes that the lift repeatably reaches its endpoint in the programmed time.
The challenge with this approach is that if the lift is not repeatable in its movement you can over/underdrive the motors when the unit gets to the stop. I tried an open-loop approach with a shade controller and it was not accurate enough without end stops.
I have been working (causally) on a shade controller that uses an inching relay as the front end to process the Google voice commands and starts an Arduino to control the up-down of the motors and end-stop recognition. This allows a closed-loop design with cheap voice recognition (no google interface programming). I can share it if you are interested.
The other annoying element of this approach is that in Goole home you have to set up a device with two channels one for up and one for down.
- Build your own ESP32 controller:
Much more complicated, but a wifi-based controller could be built that interfaces with IFTT and that in turn with Google Home. This would still need the device control from #2 but would be a cleaner Google home interface.
You would need a cloud service to manage the device and an IFTT account.