Hi~
You can dowmload this Arduino:https://github.com/Seeed-Studio/Arduino_IDE_for_RePhone
Then open the example: https://github.com/Seeed-Studio/Arduino_IDE_for_RePhone/tree/master/hardware/arduino/mtk/libraries/LGSM/examples/sms_test
However, an error occurs at compile time，it is some thing about “endSMS”. Don’t worry, open this two file:LGSM.h and LSMS.cpp https://github.com/Seeed-Studio/Arduino_IDE_for_RePhone/tree/master/hardware/arduino/mtk/libraries/LGSM. Find all “sendSMS” and change to “endSMS” and save files.
Now, compile and try to use your SIM card send a messageto your friend.