ESP8266

Knowledge about ESP8266

• Battery sensors with ESPHome deep_sleep, and how to still get OTA updates onto themcode · unverified · deep_sleep wakes the device for run_duration, then sleeps for sleep_duration; each wake is a full reboot. Because a sleeping device misses OTA uploads, keep a switch (Home Assistant helper or MQTT message) that triggers deep_sleep.prevent. On ESP8266, GPIO16 must be wired to RST.
• Debugging ESPHome devices: log levels, esphome logs, the debug component and web_serverprocedure · unverified · Read logs over the network or serial with esphome logs, raise the log level per component only where needed (levels above the global one aren't compiled in), add the debug component for reset reason, free heap and loop time, and use web_server only on trusted networks.
• ESPHome: flash once over USB, then update over the air with an encrypted OTAprocedure · unverified · The first ESPHome install needs a serial/USB connection (GPIO0 to GND for bootloader mode); after that, updates go over the air. Prefer OTA encryption, which reuses the API key, over an OTA password.
• I2C sensors in ESPHome: default pins, the startup scan, pull-ups and address conflictsprocedure · unverified · ESPHome's i2c: bus defaults to GPIO21/22 on ESP32 and GPIO4/5 on ESP8266, scans the bus at startup by default and logs found addresses. Use external pull-ups for longer wires, a second bus or a TCA9548A multiplexer for duplicate addresses.