MOSI (Master Out Slave In) - This pin is the SPI input to the module. Through this pin module receives the data from the microcontroller ... and VCC pin of this module to the GND and VCC of Arduino ...

With just an Arduino UNO R4 and a few lines of code, you can make that happen—no expensive GSM module required. To make Arduino send a text message to your phone without using a GSM module, you don’t ...