From: jeroen@nospam.please   
      
   On 12/26/25 11:37, Don Y wrote:   
   > On 12/26/2025 3:27 AM, Liz Tuddenham wrote:   
   >> Don Y  wrote:   
   >>   
   >>> Any pointers regarding deployment of pressure sensors measuring   
   >>> air pressure?  I'm looking at nominally an inch of water   
   >>> (pressure/vacuum)...   
   >>   
   >> Washing machine/diswasher water-level switches?   
   >   
   > No, I'm looking at pressures in air handling systems.   
   >   
   > In systems that I've designed previously, someone   
   > else selected (very expensive!) transducers and   
   > I just had to interface with them.   
   >   
   > But, those were industrial systems with dedicated   
   > staff to keep them running, calibrated, etc.  You   
   > cared about the actual "numbers" from the sensors   
   > because you were controlling "regulated" processes   
   > and needed to document compliance/exceptions.   
   >   
   > I'm trying to leverage some of those algorithms but in a   
   > cheaper consumer market where stuff "just has to work".   
   > I don't care about numbers as much as *trends*, using   
   > adaptive algorithms to sort out what's "normal" from   
   > "indicating".   
   >   
      
   I've had some fun with teeny tiny BME280 sensors. They   
   have a sub-1% absolute accuracy and enough resolution   
   to detect the pressure change between your head and your   
   feet. They measure temperature and humidity too. The   
   interface is I2C.   
      
   Jeroen Belleman   
      
   --- SoupGate-DOS v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)