What do the different on-board LEDs on the Meadow indicate?


Is there documentation that defines the functionality of different LEDs on Meadow board?

Especially I’m interested in knowing what does this LED indicate? First it blinks, then it blinks faster until it is practically ON all the time. It might take minutes to hours before this happens after launching the program.

The board is being powered via the 5V-pin. Ground is in the ground pin. The power comes from an USB charger. I’ve used one with 1 A and another one with 2 A capacities.

The board communicates with three external devices with serial-UART, I2C and SPI-buses. Two of the external devices are powered with 3.3 V external regulator (1117). Meadow and one device use the 5V power.

It goes OFF and does not blink anymore when I plugin the onboard micro-usb-port to an USB-port of a computer.

I might have a problem that Meadow / some of the external devices / the code stops working (running) after some period of time (that varies between a couple of hours to several hours). The possible problem might occur about the same time the LED starts going ON, but I’m not sure yet.

Nevertheless, I would like to know what does this LED indicate. Thanks!


I assumed the LED (and the possible problem) is related to powering of the board. I changed the power from 5V to 3.3 V. The system seems to be more stable now, but lets see how it goes in the long run.

The LED indicated is the charging indicator. It should normally light when a battery is being charged.

We have just released beta 3.12 of the OS and libraries. You may find that this resolves the problems with applications stopping after a period of time as we have fixed an issue with the garbage collector.



Thanks for your response.

Thanks for the tip. I will download the latest OS.

After I changed the power from 5V to 3.3 V the system has been running without any problems for 12 hours now and still going on smoothly, even with an older OS (0.3.6 or 0.3.9, if I recall correctly). And the battery charging LED has been OFF the whole time.

Actually, now that I checked the status of the system more carefully, I noticed that it has stopped after about two hours of running. I will try if the new OS helps with this issue.