Here is the code, it works fine after an upload from the Arduino IDE. But with both powercycle and reset debug flash works but no tx led flashes. (also tried external power 9v 1A no tx either)
void setup() {
pinMode(LED_BUILTIN, OUTPUT); //set debug blink
digitalWrite(LED_BUILTIN, HIGH); //debug blink on
Serial.begin(9600);
while(!Serial);
Serial.flush();
delay(30000);
digitalWrite(LED_BUILTIN, LOW); //debug blink off
Serial.print("ATD06********;\r");
delay(5000);
Serial.print("ATH\r");
delay(300);
}
void loop() {
}