In this post I will explain how I got my pressure sensor QDW90A-3 working from AliExpress.
I think following devices work the same : QDW90A, QDW50A, QDF70B, QDL80A
The unit I bought has a 0-10 bar range.
It outputs the value on register 4, with 2 decimals.
So 10 bar = 1000, 1.23 bar = 123
The connecting part is a metric 20mm thread, with 1.5 stepping.
As we have all our water plumping in BSP I needed a 20mm → 3/4 BSP convertor, which I bought on AliExpress as this is very hard to find in a hardware store.
These sensors are connected by a modbus, I have made a previous post how to connect them to a EW11 modbus<->wifi bridge : # Modbus with EW11 + QDY30A RS485 water level measure probe
Connecting the probe to the EW11 :
[u]Sensor <-------> Elfin EW11[/u] <------> 24V power supply
BLUE A
RED + +
BLACK - -
YELLOW B
configuration.yaml home assistant
modbus:
- name: "dr-tom-ew11-rs485-wp-2"
type: tcp
# host: dr-tom-ew11-rs485-wp-2
host: 10.0.6.246
port: 502
timeout: 3
sensors:
- name: "Water pressure"
slave: 1
address: 4
data_type: int16
unit_of_measurement: bar
input_type: holding
scale: 0.01
precision: 2
scan_interval: 5