Make your gas/water meter smart

Forecasting the whole gas and water costs is actually much more interessting than some years ago. To do so it is neccessary to have smartmeters installed by your utility company. If this is not the case like in my home it is common that most meters provides an impulse counter, simply a magnet. This magnet can be used to record the consumption simply by counting the impulses.

There are some projects included tasmota that provided impulse counters but I decided to create my own to have it specialzed to my purposes included a WebUI.

Featurelist

• MQTT publishing to get logging information
• Realtime clock for logging
• Guided setup to avoid storing WiFi password, etc. in the code
• NVRAM backup of the actual value
• error message of it was offline longer than 10 minutes with realtime clock (NTP)
• build in LED shows reed sensor status

Hardware

• MH-ET Live D1 mini ESP32
• STL for case (thingiverse)
• Reedsensor has to be connected to ground and GPIO 27 (can be changed in the constants, every digital GPIO can be used)
• sensor case for Pietro Florentini/Samgas meters

Mounting

The reed sensor has to be mounted near to the magnet. For Pietro Florentini/Samgas meters I included a STL to mount the reed sensor. It has to be placed near to the outer wall of the mechanical counter, below the lowest red number.

Software

On first boot the thing opens an Access Point named "Gaszaehler" to provide the setup interface. The interface is still available after the device is connected so you can change everything later. You can compile your own firmware version or use the firmware provided in the releases section.

1. Do the system configuration and set things name (hostname), AP password (if WiFi connection is lost) and WiFi credentials for your network.
2. MQTT configuration (optional)
   1. publish the following topics (folder structure can be changed):
      • "ht/gas/imp_counted_1": actual impulse count
      • "ht/gas/imp_value_1": actual value consumed
      • "ht/gas/heartbeat": shows an error if the device was more than 10 minutes offline
      • "ht/gas/downtime": number of seconds the thing was switched off
      • "ht/gas/info": some status information
3. NTP configuration to get RTC infos for logging (default is fine for german timezone)