Monitoring a pizza oven temperatures with an ESP32 and BLE

Simple device that monitors the temperature of the pizza oven and continually sends updates via BLE to my phone. In addition to real-time updates all temperatures should be stored locally on the esp32 where they can later be pulled off and graphed to track ramp-up and ramp-down times.

Features v1

  • Simple, small, battery powered.
    • AA are easier/cheaper but would require a booster.
  • Sleeping most of the time, when activated it would wake up for 2-3 hours and start sending temperature readings.
  • Thermocouple Type-k connector to measure the high temperatures
  • Basic iOS app that reports temperatures, downloads data from the esp-32 and uploads to the cloud
  • Semi watertight so if left out it doesn't get ruined.

Future features

  • Permanent with either rechargeable batteries via solar or large enough battery to last an entire season.
  • Auto on if temperature goes above x degrees.
  • Alerts when temp reaches a certain point


  • Storeing values as 8bit ints to keep it simple. That means we're losing resolution since temperatures are floats. For this, I'm fine with that.
  • Our min/max temp range is 0-255 since we're storing them in 8bit ints. Again, for this that's perfectly fine.