Lechuza watering reminder with Aqara Door Sensor

The main holder has a friction fit for 10mm and 12mm original Lechuza Indicators without the clear cap. To remove the clear cap you need to get to the clips from the bottom of the cap. The Extension compensates for the deeper dip of the stick due to the added weight of the magnet. Its a N52 10mm x 2mm cylindrical magnet from eBay to trigger the reed switch of the AQARA PCB. The backcover can be clipped on but is not water tight. Becareful when refilling your pots!

To mount the PCB of the Aqara Door sensor I put in a little tab to rest it on and a tiny bit of Hotglue to fix it in place (See pictures).

Full(Open) is when the magnet is flush to the top, and <20%(Closed) is marked on the side of the Holder. Some reed switches are Soldered in a different orientation which might give some trigger issues. Shortening the extension by 2-5mm helps.

All of it was printed with PLA filament form DAS FILAMENT. The extension is just a single Perimeter for a .4mm nozzle. I printed it with a 5mm Brim.

I use this in an openHAB Rule that sends a Telegram Notification roughly every 8h:

var Timer Timer = null


rule "plant needs water"
when
    Item WaterLevelLowSensor changed or
    Time cron "0 0 0/2 ? * * *"
then
    if (WaterLevelLowSensor.state == CLOSED) {
        // If the sensor is closed, start or reschedule the timer for 6 hours
        if (Timer === null) {
            Timer = createTimer(now.plusHours(6)) [|
                // After 6 hours, send a Telegram message
                val telegramAction = getActions("telegram","telegram:telegramBot:Telegram_Bot")
                telegramAction.sendTelegram("The plant needs water")
                Timer = null // Reset the timer
            ]
        }
    } else {
        // If the sensor is opened, cancel the timer
        if (Timer !== null) {
            Timer.cancel
            Timer = null
        }
    }
end

Works great for me for about 2 Months now.

The Model was designed in Fusion360 with parameters.