• Current temperature shows in large LED display
• Min and max temperatures, date and time of day recorded for the last several months
• Temperature records downloadable as JSON over HTTP for display or further processing
• Date and time synchronized from online time servers (NTP)

• ESP-01 board
• DS18B20 temperature sensor
• TM1637 based 4-digit 7-segment display
• 3.3V LDO

$ git clone https://github.com/rogerdahl/esp8266-min-max-thermometer.git
$ cd esp8266-min-max-thermometer

Proper timezone support isn't working. Currently must be hard coded by modifying the calculation done in main/ntp.c, getLocalNow():

$ editor ./main/ntp.c

The default GPIO configuration is set up for the ESP-01 board, using the UART RX/TX pins for communicating with the LCD display. So idf.py monitor won't work. This just builds and flashes the module, which can then moved over to the hardware board. For development work, use a board that breaks out more pins and modify the settings for ONEWIRE_PIN in onewire.c, and TM1637_CLK_PIN / TM1637_DIO_PIN in tm1637.c.

$ . ~/esp/ESP8266_RTOS_SDK/export.sh 

$ idf.py menuconfig

    > Example Connection Information
      > WiFi SSID
      > WiFi Password

$ idf.py fullclean build flash