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 11:11:35

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 switch˙ TPL5110 
> until I blew it up and replaced it with a sub-board˙ 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)

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