Send SMS with Particle Electron

[ScruffR]

I'd guess it's the double plus sign ++ in your phone number.

I had posted some code some while ago

Electron with Australia Telstra Sim and Sending SMS

Just recently I did something like that for another project SYSTEM_MODE(SEMI_AUTOMATIC) SYSTEM_THREAD(ENABLED) STARTUP(cellular_credentials_set("yourAPN", "", "", NULL)) SerialLogHandler serlog; #define RADIO Cellular int placeCall(const char* telNr, uint32_t duration = 30000); int sendMessage(const char* telNr, const char* msg); void setup() { RADIO.on(); RADIO.connect(); Particle.connect(); } void loop() { static uint32_t ms = 0; if (millis() - ms > 60000) { …