Mkrfox1200 on battery not sending to Sigfox


my Arduino MKRfox1200 works well when connected to Mac usb power source. It sends data to Sigfox.

When connected to battery 5v USB or 2x AA it does not send anything to Sigfox. LED is blinking when it seems to be sending data, but there is nothing received on Sigfox console. Any idea what is the issue reason?

I experience the same problem as you. MKR 1200 sends data when connected to USB (tested both powerbank and mac) but it fails sending when operated on 2 AA batteries connected to the green connector.

Have you got any advices how to solve this?


Hello, do you resolve this issue? I am in the same situation.


After a lot of hours I could resolve the issue, it was because the code, you have to change the:

while (!Serial) {}


while (!Serial) {
  if (waiting> 9) {
    debug = false;

Before the Arduino was search of the Serial connection, and with the battery there is not that connection. With the new code it works good.