The M2 sensor communicates its status through coloured lights on the front. Press the main button (the lens) on the front of the sensor to check its current state at any time.
The M2 sensor was discontinued in 2022. Existing M2 sensors are fully supported until at least 2029. For new installations, see the M3 sensor
Quick reference
Colour | Pattern | What it means |
Blue | Solid on startup | Sensor is powering on |
White | Circling | Connecting to Wi-Fi or Minut server / updating firmware |
Green | Solid | Online and monitoring; all good |
Purple | Solid (long press) | Setup mode: ready to connect to Wi-Fi |
Red - 1 blink | Single blink | Battery empty |
Red - 2 blinks | Double blink | Cannot connect to Wi-Fi |
Red - 3 blinks | Triple blink | Connected to Wi-Fi but cannot reach Minut server |
No light | - | Sensor is off, or power switch is set to OFF |
What each light means in detail
Blue- solid
Appears when: the sensor powers on
Sensor is starting up
The M2 shows a blue light every time it powers on; when you turn the power switch to ON, after a battery charge, or after a restart. This is normal and brief. The sensor will move to white circling, then settle to green once it has connected to Wi-Fi and the Minut server.
No action needed; startup in progress
White- circling
Appears when: starting up, connecting, or updating
Connecting or updating firmware
The sensor is connecting to Wi-Fi, syncing with the Minut server, or installing a firmware update. This is normal and may take up to a minute. Do not turn the sensor off or disconnect it from power while it is showing a white circling light; you may interrupt a firmware update.
Do not turn off while white is circling
Green- solid
Appears when: pressing the main button while online
Online and monitoring; all good
The sensor is connected to the internet and running correctly. This is the expected state during normal operation. Pressing the main button (the lens) will show a green light to confirm the sensor is working.
No action needed
Purple- solid
Triggered by: long press of the main button
Setup mode
The sensor is in setup mode and ready to connect to a Wi-Fi network. This light appears when you press and hold the main button (the lens) during installation or when updating Wi-Fi settings. The sensor is broadcasting the Point Configuration network at this stage for your phone to connect to.
During installation; connect to Wi-Fi in the app
Red- blinking
Appears when: pressing the main button and something is wrong
Error: count the blinks carefully
A red blinking light indicates a problem. The number of blinks tells you exactly what is wrong.
1 blink: Battery is empty. Connect the sensor to a charger via Micro-USB. Make sure the power switch is set to ON — the sensor will not charge if the switch is OFF. See M2 charging and battery
2 blinks: Cannot connect to Wi-Fi. Check the power switch is ON and the sensor is within range of your router. Confirm you are connecting to a 2.4 GHz network. You may need to update the Wi-Fi setting; see Wi-Fi and connectivity.
3 blinks: Connected to Wi-Fi but cannot reach the Minut server. The router has internet access issues, or a firewall is blocking the connection. Try rebooting the router. If the issue persists, see What to do when your sensor turns offline.
No light
No response when main button pressed
Sensor is off or power switch is set to OFF
If pressing the main button produces no light at all, check the power switch on the back of the sensor first; the M2 has a physical power switch that must be set to ON for the sensor to operate or charge. If the switch is ON and there is still no response, the battery may be completely flat. Connect via Micro-USB for at least 10 minutes before trying again.
Check the power switch on the back is set to ON
Charging indicator lights
The M2 also has indicator lights on the back of the sensor to show charging status. These are separate from the front status light.
Blinking lights
Sensor is currently charging. The lights pulse rhythmically while the USB-C cable is connected and power is flowing.
Solid green lights
Sensor is fully charged. A full charge takes approximately 6 hours from empty.
The sensor must be switched ON to charge. The M2 has a physical power switch on the back. If the switch is set to OFF, the sensor will not charge regardless of whether it is connected to a charger.
For full battery life and charging details, see M2 charging and battery information.