readme.md

A low power FireBeetle ESP32-E based thermometer with an ePaper display

See docs/wiring.md for wiring information.

See docs/notes.md for notes on current consumption.

Hardware

Controller board

• Firebeetle ESP32-E https://wiki.dfrobot.com/FireBeetle_Board_ESP32_E_SKU_DFR0654

• ESP32 datasheet https://www.espressif.com/sites/default/files/documentation/esp32_datasheet_en.pdf

• ESP32-WROOM-32E datasheet https://www.espressif.com/sites/default/files/documentation/esp32-wroom-32e_esp32-wroom-32ue_datasheet_en.pdf

• TP4056 battery charger IC https://dlnmh9ip6v2uc.cloudfront.net/datasheets/Prototyping/TP4056.pdf https://www.best-microcontroller-projects.com/tp4056.html

• ESP32 getting started https://docs.espressif.com/projects/esp-idf/en/latest/esp32/get-started/index.html

• ESP32 power consumption https://diyi0t.com/reduce-the-esp32-power-consumption/

Temperature sensor (multiple options)

• DS18B20-PAR OneWire interface
  • datasheet https://datasheets.maximintegrated.com/en/ds/DS18B20-PAR.pdf
• BMP390L I2C interface:
  • datasheet https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bmp390-ds002.pdf
  • breakout board https://wiki.dfrobot.com/Fermion_BMP390L_Digital_Barometric_Pressure_Sensor_SKU_SEN0423

Display (multiple options)

• Adafruit 1.54" Tri-Color eInk / ePaper 200x200 Display with SRAM - SSD1681 Driver https://www.adafruit.com/product/4868 https://learn.adafruit.com/adafruit-1-54-eink-display-breakouts?view=all
  • uses Good Display GDEH0154Z90
• Good Display GDEW0154M09 black and white, 200x200, 1.54" fast full refresh
• Good Display GDEW0213M21 black and white, 212x104, 2.13" DES screen

Battery

• RS Pro 18650 26H Li-ion Battery Pack https://fr.rs-online.com/web/p/batteries-taille-speciale/1449406/