Automations & hardware

Common questions

Answers to the questions that come up most when setting up Automations hardware — choosing a device, fixing offline controllers, sensor voltages, pins, and security.

Which device should I choose?

• ESP32 — cheapest and quickest for one relay or a sensor or two. You flash it from your browser and pair it over Wi-Fi.
• Raspberry Pi — best when you want several relays and sensors on one unit or a more capable controller. No flashing — you run a one-line installer.
• HTTP (token) — no hardware at all; for feeding readings in from another system that can send web requests.

All three work with the same rules and scenes, so you can mix and match across a site.

Why is my device showing offline?

A device drops offline when it loses Wi-Fi or power. Check, in order:

1. The controller has power and is within Wi-Fi range.
2. The Wi-Fi password you entered during setup is still correct (a changed router password takes devices offline).
3. For an ESP32, re-join the Mavos-Setup hotspot and re-enter the network details.
4. For a Pi, confirm it booted and is on the network.

Devices reconnect on their own once Wi-Fi and power return. You can have a rule alert you whenever a controller goes offline.

Can I use 5V sensors?

The boards run at 3.3V logic. Many sensors are fine at 3.3V, but if a sensor's output can reach 5V you must drop it to 3.3V with a voltage divider or level shifter before it reaches a pin — otherwise you can damage the board. Powering a sensor from 5V is usually fine; it's the signal voltage that matters.

What's a "strapping pin", and why the warning?

A few ESP32 pins are read at power-on to decide how the board boots. They work normally once running, but if one is held at the wrong level at the moment of power-on the board may fail to start. The editor lets you use them but flags them — prefer a plain GPIO for anything connected at boot.

Why can't I use GPIO 0?

GPIO 0 is the ESP32's boot / factory-reset pin. Driving it (for example with a relay) can make the board reset or wipe itself, so the editor blocks it entirely. Pick any other offered pin.

Do I need to write any code?

No. Flashing (ESP32) or the installer (Pi) puts the standard Mavos firmware/agent on the device once. After that, you only configure channels in the app — saving a channel pushes the new pin configuration to the device automatically within a few seconds.

How many channels can one device have?

Up to 32 channels per device, though a small ESP32 board will run out of usable pins long before that. A Raspberry Pi has more pins, making it the better choice for many channels on one unit.

Should a lock relay use Pulse or stay On?

For an electric strike or maglock, use a timed Pulse so the lock always re-locks even if something interrupts the flow — far safer than leaving it switched On. Pair it with a door switch channel so a rule can confirm the door actually closed.

My relay clicks but the load doesn't switch — or on/off is reversed

• If it clicks but nothing happens, check the load's own power supply and that the load runs through the relay's switched terminals (COM / NO).
• If on and off are swapped, your relay module is likely active-low — turn on Invert (active-low) for that channel.

Is the data secure?

Controllers connect over an encrypted, authenticated link, and each device has its own credentials so one can be revoked without affecting others. HTTP devices use a secret token you can rotate at any time. Always send HTTP readings over HTTPS.

Still stuck? See the Wiring reference, the ESP32 and Raspberry Pi setup guides, or contact support.