I connect my SIM900A mini module with 4V. It’s LED is blinking fast about 1secons. When I send AT to the module it does not show anything it just show AT only. Why module does not sends OK responses.
I connected RXD 5v to TX and TXD 5v to Rx. It is not working for different boud rates.
I change coonnection RXD 5v to RX and TXD 5v to Tx. It is not working for different boud rates.
AT command send and not response only show AT in terminal.