What do the flashing LEDs mean?

AudioMoth has two colour LEDs, visible on the side of the device. Various combinations of these two LEDs flashing represent different modes of operation or tasks it is carrying out.

With switch set to CUSTOM:

When a recording schedule has been set but the clock has not been set, or when the "Always require acoustic chime on switching to CUSTOM" is checked, the AudioMoth will listen for the acoustic chime from the AudioMoth Chime smartphone app. While doing this the red light will remain solid whilst the green flashes (100ms).

Once the chime has been played and accepted, the red LED will switch off and the green will be solidly lit for a short period (2s), then the schedule will begin.

When sleeping between recordings a single green light will flash (10ms) while the red remains unlit.

When making a recording a single red light will flash intermittently depending on the sample rate as the recording is written to the SD card.

Both lights flashing (100ms) on first switching to CUSTOM means that no recording schedule has been set.

A long flash (500ms) of both LEDs occurs when there is a recording failure, due to an SD card write error or a low battery, that results in a recording being cut short.

Short flashes (10ms) of both LEDs between recordings mean an earlier scheduled recording has been cut short due to a recording failure.

With switch set to DEFAULT:

When making a recording a single red light will flash intermittently depending on the sample rate while writing to the SD card.

A long flash (500ms) of both LEDs occurs when there is a recording failure, due to an SD card write error or a low battery, that results in a recording being cut short. If this happens immediately on switching to DEFAULT check that the SD card is inserted correctly

With switch set to USB/OFF:

When connected to USB the green LED will remain on constantly.

When first switched to USB/OFF, the red LED will flash (100ms) a number of times corresponding to the current battery level of the device.

There are two battery level modes. The default one is intended for use with standard alkaline batteries (left), and a second more precise scale is available for use with NiMH and LiPo batteries (right). The second scale is selected using the "Use NiMH/LiPo voltage range for battery level indication" setting in the AudioMoth Configuration App.

Alkaline (V)

≥ 4.6

4.4 - 4.5

4.0 - 4.3

3.6 - 3.9 

≤ 3.5

Flash Count





10 rapid

NiMH/LiPo (V)

≥ 4.3

4.2

4.1

4.0

3.9

3.8

3.7

3.6

≤ 3.5

Flash Count









10 rapid

©2020 Open Acoustic Devices