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By AshanG

I'm using a SARA R4 NB-IOT/CAT M1 shield with an Arduino Uno. I have used TCP_Send_Hologram example to send data to the Hologram dashboard and it works fine. But the problem I'm having is that the module turns itself OFF sometimes and won't turn ON when I try to send a message.

The hookup guide says "The library is designed to toggle the POWER pin if the shield is not communicating, so you may be able to avoid pressing this button at all".

Is there a way to toggle the POWER pin again (without pressing power button) when sending a message or to keep it ON without toggling the POWER pin OFF?
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By TS-Chris
Hello AshanG. Thanks for you post.

I've not seen this behavior before, but an easy way to toggle the power for the SARA module would be to drive Arduino pin D5 low for 3200ms then set D5 as an input. Something like the code below should do the trick.
Code: Select all
    pinMode(5, OUTPUT);      //Make D5 an output pin. (High or Low)
    digitalWrite(5, LOW);    //Drive D5 low.
    delay(3200);             //Wait 3200ms
    pinMode(5, INPUT);       // Return D5 to high-impedance, (rely on SARA module internal pull-up)