Subj : Re: OIL level sensor (was ODD DNS behaviour on Pi ZERO W with Bullseye
To   : All
From : The Natural Philosopher
Date : Wed Nov 19 2025 19:36:05

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

On 19/11/2025 17:24, Daniel James wrote:
> 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. :-)
> 
I have used mine fairly cosistently to make cases, duplicate broken bits 
of plastic, and for all manner of things I simply never thought of.
I got a pair of RAACO cabinets that were not shipped with drawer 
dividers. The cost of printng was less than the cost of buying them...etc.

The upfr9nmt cost is a bit steep, but hey - the more toys the better....


>> 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.
> 
Ah yes. I am a believer in 'use what you know of and have already'


> 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 probably 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.
> 
> 

-- 
"When a true genius appears in the world, you may know him by this sign, 
that the dunces are all in confederacy against him."

Jonathan Swift.


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

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