Christian Bumberger

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PlantPal Bridge

The Flower Care sensors in your pots talk via Bluetooth – which only reaches a few metres. The PlantPal Bridge is a small ESP32 plugged into a socket at home. It listens to the sensors and sends their readings to PlantPal every 5 minutes. So you see soil moisture, light and fertilizer at the office or on vacation, and the history has no more gaps. The Bridge is part of PlantPal Plus.

What you need

  • PlantPal Plus on iPhone, iPad or Mac.
  • One or more Flower Care plant sensors (HHCCJCY01), already assigned to a plant in PlantPal.
  • An ESP32 board with Bluetooth, ideally an ESP32-S3 or ESP32-C3 with a USB-C port (e.g. ESP32-S3-DevKitC or ESP32-C3 SuperMini, a few euros). A classic ESP32 works too.
  • A USB cable that carries data (charge-only cables don’t work), and later a USB power supply.
  • A 2.4 GHz Wi-Fi network.
  • For installing, once, a computer with Chrome or Edge (Mac, Windows or Linux). Safari and Firefox can’t do this.

1. Install the firmware

  1. Connect the ESP32 to the computer via USB.
  2. Click “Install Bridge firmware”, pick the ESP32 in the list and confirm. It takes about a minute.
  3. Afterwards the LED (if the board has one) blinks blue: the Bridge is waiting to be set up.

Your browser can’t install firmware. Open this page on a computer in Chrome or Edge. Installing needs a secure connection (https).

If the ESP32 doesn’t show up in the list, try another USB cable. Older boards connected through a USB-serial chip (CH340, CP2102) sometimes need a driver from the chip maker on Windows. The firmware comes straight from this page; nothing is installed on your computer.

2. Set it up in PlantPal

  1. Plug the Bridge into a USB power supply within Bluetooth range of your iPhone, iPad or Mac.
  2. In PlantPal open Settings → Sensor Bridge → Set up Bridge.
  3. Choose “PlantPal Bridge”, then your Wi-Fi, enter the password and tap “Set up Bridge”.
  4. After about half a minute PlantPal reports that the Bridge is set up. The LED turns green.

The Wi-Fi password goes only to the Bridge, not to PlantPal. The Bridge finds new sensors on its own; their readings appear on the plant the sensor is assigned to in PlantPal.

3. Placement

Indoors, Bluetooth reaches about 5 to 10 metres, less through walls. Put the Bridge roughly in the middle of your plants. If one isn’t enough, simply set up a second one – PlantPal uses the newest reading for each sensor.

LED

  • Blinking blue: not set up yet.
  • Blinking orange: no Wi-Fi (password changed, router off, 5 GHz only?).
  • Turquoise: on Wi-Fi, nothing sent yet.
  • Green: all good, sends every 5 minutes.
  • Red: the PlantPal server refuses, usually because the Bridge was removed – set it up again in PlantPal.

Set up again or reset

You can set a new Wi-Fi in PlantPal during the first 10 minutes after plugging in (Sensor Bridge → “Set up another Bridge or new Wi-Fi”); if the Bridge can’t find its Wi-Fi anymore, setup is open anyway. Holding the BOOT button on the board for 5 seconds erases Wi-Fi and key and restarts the Bridge. The trash button next to the Bridge in PlantPal (Settings → Sensor Bridge) deletes it and its readings on the server.

What the Bridge sends

For each sensor an identifier made of the last three bytes of its Bluetooth address, plus soil moisture, light, fertilizer (conductivity) and temperature, registered with a random key that PlantPal creates during setup. My server keeps the readings for 7 days. More in the privacy policy.