From: daniel@me.invalid   
      
   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.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)