Rx and / or Tx lights stuck on - USB malfunction


Hi Team,

I have two Blend Micro boards, I uploaded the BLEController example sketch to both of them. I tested functionality by connecting with my phone and setting pin 13 as an output and then triggered it to see the on-board LED go on and off.

But when I uploaded the SimpleChat example sketch, the Rx light on one board stays on all the time now and the Rx and Tx light on the other board stays on all the time now. When plugging the boards into the computer the computer says that the USB device has malfunctioned.

I’ve tried uploading other example sketches and a blank sketch to the boards, which I can do if I hold down the reset button and then release it at the correct time. I can confirm that the upload at this point works because the blend micro now responds with a new program on there, like the blink program for example, but the Rx and Tx lights stay lit.

There has never been anything other than the USB connected to the boards.
I was wondering if there was a more in-depth reset I could do, like rewriting the firmware but I can’t find a copy of the firmware to try that.

Does anyone know what might cause this and what I should try to remedy it?



When you pressing the reset, the board will go into the bootloader mode for some seconds, during this time, you can upload sketch to it.


Hi Cheong,

Thank you for your response. I have pushed the reset button and uploaded a new sketch in the first few seconds, I can confirm that that new stack uploaded correctly because I uploaded the blink sketch and now the led blinks but the Rx light still stays on.

I also uploaded a blank sketch and still the light stays on.

Is there another kind of reset I can do? Maybe flash the bootloader?