Pressure sensor

Hardware
1

Hi folks,

I’m looking to build a sensor to monitor water pressure (1 - 3 bar). I was planning on using a ESP32 with a linear voltage sensor.

Can anyone point me in the direction of a reasonably priced unit. Anything I have found is 100+

Thanks
Padraic

2

DIY?

ESPHome and a 4-20mA or 0-3.3V one of these: https://www.aliexpress.com/item/1005008462356803.html

3

Thanks Tom, looks like what I’m looking for. I had searched aliexpress but didnt find them.

Yes DIY with ESPhome. I was doing some reading on them and believe a voltage input might be easier to manage than a 4-20mA. The article i was reading mention a 4.5v one and usiing a 100 ohm resistor to divide the voltage. Any thoughts?

4

0-3.3V voltage output is perfect if you don’t have really long wiring (in that case go with 4-20mA or RS485).

5

4-20mA can be detected with a 150 Ohm resistor (4-20mA → 0.6-3V) or with an INA219 current sensing module.

RS485 would be more complicated.

Do you have a way of calibrating the reading?

6

Here’s some older stuff - I’m running two of the DFRobot ones ( Gravity: Analog Water Pressure Sensor - DFRobot) connected to a Wemos D1 mini each:
Water Pressure Z-wave - wifi: monitor pressure of city water - Hardware - Home Assistant Community

7

This may be of interest to folks following this topic:

8

That’s flow, not pressure. Also until I see some real world tests I’m going to assume it is terribly inaccurate.

1 Like
9

I have multiple analogue guages on the same system. Can these be used as reference points to calibrate?

10

Yep, that would work. See: Sensor Component - ESPHome - Smart Home Made Simple