I have an Arduino MKR1500 NB board. Firstly I used with a Vodafone NB-IOT sim card, with this working well without issues.
But If I insert a different NB-IOT sim cards, it freeze after 5-10 sec and doesn't response answer to at commands. I have a telekom and hologram sim card.
I have a SIMCOM 7020 modem and in this working perfectly all sim so the cards are ok!
Does anyone have any idea what could be wrong?
I am using this very simple code and I using the serial monitor for the at commands.
// baud rate used for both Serial ports
unsigned long baud = 115200;
void setup() {
// NEVER EVER use RESET_N
pinMode(SARA_RESETN, OUTPUT);
digitalWrite(SARA_RESETN, LOW);
// Send Poweron pulse
pinMode(SARA_PWR_ON, OUTPUT);
digitalWrite(SARA_PWR_ON, HIGH);
Serial.begin(baud);
SerialSARA.begin(baud);
}
void loop() {
if (Serial.available()) {
SerialSARA.write(Serial.read());
}
if (SerialSARA.available()) {
Serial.write(SerialSARA.read());
}
}