Subj : Re: OIL level sensor (was ODD DNS behaviour on Pi ZERO W with Bullseye
To   : All
From : Daniel James
Date : Wed Nov 19 2025 17:24:14

Subject: Re: OIL level sensor (was ODD DNS behaviour on Pi ZERO W with Bullseye OS)

On 19/11/2025 12:16, The Natural Philosopher wrote:
> One of these basically
> 
> https://www.fueltankshop.co.uk/2500-litre-oil-tank-titan-h2500gr/p5305
> 
> The tank already had a hole in the top to take an oil watchman sensor, 
> so I 3d printed a case to use the same mounting holes and gasket. I will 
> need to open up the hole a bit for the ultrasonics

Ours is a steel tank, but it has a tube poking out of the top that has 
previously accommodated a Watchman sensor.

Housing the electronics is the problem - I had hoped that oil tank 
sellers would sell a screw-in cap for the tank opening that I could 
cannibalize to make an appliance housing, but I haven't found anything 
suitable (yet).

I really needed an excuse to get into 3D printing. :-)

> Well since I am 100% custom I didn't bother with mqtt - I simply send a short text string . The more problematical bit is establishing a wifi connection and what to do if it fails to connect.
> 
> If I had Ethernet out there I would never have gone to the complexity of battery operation....

I used MQTT because I already had Mosquitto running on the Pi3B (as part 
of a HomeAssistant setup controlling a few Tasmoto switches). I should 
not have gone that route otherwise ... but it does work well.

Yes, if I had Ethernet running out to the tank it would all be so 
different ... but I'm not drilling a hole through a 60cm stone wall to 
get it there!

>> I have a 3V-compatible HCSR04 to play with ...
[snip]
>
> Good with the 3v version Mine isn't and I expect it to get sketchy at around 3.9V.
> If that proves to be a problem I'll probab;y make a new board up and transfer the modules from the existing...

Mine is actually an RCWL-1601, which claims HC-SR04 compatibility. It 
also claims to support i2c as well as the usual trig/echo signalling, 
which will help as me ESP8266 is running out of pins. I may have to 
switch to an ESP32 ... but I have a handful of 8266s not doing a lot ...

> I don't like the commercial solutions that rely on a cloud somewhere.

No, indeed. I avoid those as much as possible.


-- 
Cheers,
  Daniel.

--- PyGate Linux v1.5
 * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

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