The opening controller
A controller has one job: to close a pair of contacts on your device — a gate, a wicket, a barrier, an intercom — for a moment, as if someone pressed Open. For bistable drives and locks there is a mode with separate open and close and position tracking. Your phone gives the command.
Choose a controller
A BLE controller takes commands from the phone directly over Bluetooth. An Internet controller is always online and opens the object from anywhere. A Raspberry Pi is also controlled over the internet, just on a small computer.
BLE controller
Takes commands from the phone directly over Bluetooth — no internet, no Wi-Fi, no server.
- Can be installed where there is no internet at all — the link runs straight from phone to controller.
- The gate needs neither network nor mains: power comes from batteries (3×AA lasts for months) or an adapter.
- The range is Bluetooth range, roughly 10–30 m: it fires when the phone is nearby.
- Opening is by a button in the app; automatic opening as you approach is available too.
- Boards: ESP32, ESP32-S3, ESP32-C3, ESP32-C6.
Internet controller
Keeps a permanent link to the server and opens the object from anywhere, even another city.
- Distance does not matter — you do not have to be near the gate.
- The gate needs permanent internet (Wi-Fi) and power around the clock.
- If the controller or you lose internet, the command will not arrive.
- An off-the-shelf Wi-Fi relay with a dry contact (Shelly Plus 1) can be reflashed, so no enclosure of your own is needed.
- Boards: ESP32, ESP32-S3, ESP32-C3, ESP8266 (Wemos D1, NodeMCU).
Raspberry Pi
Also controlled over the internet, but this is a small computer: instead of firmware there is a Python script and a relay on the GPIO.
- Not a microcontroller — the operating system handles the network (Wi-Fi or Ethernet).
- A Python script plus a systemd service: autostart and reconnection.
- Pi Zero W / 3 / 4 / 5. A relay on the GPIO or a relay HAT.
- There is nothing to flash — you copy the ready script onto the Pi and run it.
A short cheat sheet
| Your situation | Which controller |
|---|---|
| The gate has no internet or Wi-Fi | BLE |
| The gate has no mains socket | BLE (battery powered) |
| You open it while standing at the gate | BLE |
| You need to open it from afar, without driving up | Internet |
| The gate has both Wi-Fi and power | either works; BLE is simpler to install, Internet is for opening from a distance |
| An off-the-shelf Wi-Fi relay is already installed (Shelly Plus 1) | Internet — reflash it for Entrixy |
| You do not want to flash anything | no controller is needed — a webhook |
The link between phone and controller is properly protected
Over Bluetooth and over the internet alike, commands between phone and controller are encrypted: every press of Open is signed with a one-time code that cannot be captured and replayed. Details are in the guide, section "Security".
To see how the controller wires up to your device, look at "Preparing the controller" or the wiring diagram in the BLE configurator.