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)

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

On 19/11/2025 10:08, The Natural Philosopher wrote:

Oh. I designed a board with

- a Pi Pico W.
- a three pin temperature sensor ( TMP36) to monitor outside temperature
- an ultrasonic transmitter/receiver ( HCRS04) on it
- a nano power timer that (Was a sparkfun nano power switchÿ TPL5110
until I blew it up and replaced it with a sub-boardÿ with an Adafruit TPL5110 Low Power Timer ) wakes up every 2 hours, tries to make contact
with the wifi, sends a short message to the server, and then commits
suicide and shuts the timer down again.

OK, thanks. What sort of oil tank do you have and how do you fit the
sensor to it?

I'm part-way through designing something similar myself, but using an
ESP8266 to control the sensor and talking mqtt to a Pi (happens to be a
Pi3B, because I have one always-on for other things but I could have
used a ZeroW). It's really at Proof-of-Concept stage at present.

I have a 3V-compatible HCSR04 to play with, but was wondering whether an
ir laser ToF device might be better. Those ultrasonic sensors are a bit
chunky ... (I'm told there is no chance of the laser in,say, a VL53L1X igniting heating oil vapour!)

I haven't yet put either anywhere near the oil tank, yet. I'm using
readings from a BME280 to test the logic.

I have a "Cheap Yellow Display" (ESP32 with LCD) that acts as a mqtt
client and display panel ... it can record data (but doesn't yet) but
I'll probably want something more sophisticated later ... as I say, it's
all PoC at present.

--
Cheers,
Daniel.

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

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

On 19/11/2025 11:11, Daniel James wrote:

On 19/11/2025 10:08, The Natural Philosopher wrote:

Oh. I designed a board with

- a Pi Pico W.
- a three pin temperature sensor ( TMP36) to monitor outside temperature
- an ultrasonic transmitter/receiver ( HCRS04) on it
- a nano power timer that (Was a sparkfun nano power switchÿ TPL5110
until I blew it up and replaced it with a sub-boardÿ with an Adafruit
TPL5110 Low Power Timer ) wakes up every 2 hours, tries to make
contact with the wifi, sends a short message to the server, and then
commits suicide and shuts the timer down again.

OK, thanks. What sort of oil tank do you have and how do you fit the
sensor to it?

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

I'm part-way through designing something similar myself, but using an ESP8266 to control the sensor and talking mqtt to a Pi (happens to be a Pi3B, because I have one always-on for other things but I could have
used a ZeroW). It's really at Proof-of-Concept stage at present.

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 have a 3V-compatible HCSR04 to play with, but was wondering whether an
ir laser ToF device might be better. Those ultrasonic sensors are a bit chunky ... (I'm told there is no chance of the laser in,say, a VL53L1X igniting heating oil vapour!)

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...

I haven't yet put either anywhere near the oil tank, yet. I'm using
readings from a BME280 to test the logic.

I have a "Cheap Yellow Display" (ESP32 with LCD) that acts as a mqtt
client and display panel ... it can record data (but doesn't yet) but
I'll probably want something more sophisticated later ... as I say, it's
all PoC at present.

Well the history of my controller goes back 20 years when I installed everything and just threw in 'enough to get it working'

But I never had proper control. And the RF thermostat was bulky and not especially reliable. So I finally decided to mess around with a Pi.

Because the website I built on the zero has everything I want to know
exactly where I want it, the experience is MUCH better.

Sometimes stuff gets stuck after a power cut. But hard resets have
always fixed it.

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


--
Truth welcomes investigation because truth knows investigation will lead
to converts. It is deception that uses all the other techniques.


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

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.


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