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Power and Sleep
The unit is battery powered and spends almost all of its time in deep sleep. Items marked unconfirmed have not been checked on a unit.
| Source | Pin | Meaning |
|---|---|---|
| Power-up | none | first power-on or reset |
| Timer | none | next scheduled dispense, or a periodic sync |
| Front button | GPIO6 | button press (active low, pull-up) |
| Bottle eject | GPIO13 | bottle removed or changed; any change of the pin wakes the unit |
| Float switch | GPIO7 | bottle level float |
| External power | GPIO16 | external power present (active high, pull-down) |
- Timer: deep-sleep timer, sleep time in seconds times 1,000,000.
- Button: ext1 wake, this pin only, wake when low, RTC pull-up enabled.
- Bottle eject: ext0 wake. Arm the wake level opposite to the pin's current level, so any change wakes the unit. RTC pulls disabled.
- Float switch and external power: these two cannot share the ext0/ext1 sources used above (different polarity), so they need the ULP coprocessor or periodic timer polling. A ULP program would sample both pins: wake on any GPIO7 change, and wake when GPIO16 is high.
- Valve pins: GPIO9/10 are not held in deep sleep, so the board must keep the valve driver off while the chip sleeps (unconfirmed, check at a unit before enabling sleep). Switch the LED outputs off before sleeping.
After a wake the unit stays awake long enough to do its work: about 60 s when it is paired and talking to a server, about 300 s while WiFi is being set up. The window is extended while work is pending, and a button press while awake can send the unit back to sleep.
Sleep until the next scheduled dispense (waking a little early), or for a long interval (days) when nothing is scheduled.
The unit wakes on the timer even with nothing to dispense: it connects to WiFi, syncs the clock over NTP, asks the server for bottle information (remaining and maximum doses), and sends a status report.
A bottle change wakes the unit. The bottle moves through states such as new bottle installed, bottle ejected, bottle empty, and installed-but-not-authorized until the server approves it and returns its maximum dose count. A standalone replacement has to supply the maximum dose count itself.
ESPHome's deep sleep can express the timer, the button (esp32_ext1_wakeup, all-low) and the bottle eject (wakeup_pin with inverted wake level). RTC pull-ups must be enabled in an on_before_sleep lambda. ESPHome has no ULP support, so the float switch and external power need periodic timer polling or a custom component. See ESPHome Replication Plan.