I have bought an SIM900A Mini V4 GSM module. Here is the module,
I want to configure with arduino to send and receive SMS.
Do I have to connect TXD of this module--Tx of Arduino & RXD of this module--Rx of Arduino or other way around?
There is no datasheet or documents on this new module.
When I search about RXD & TXD, I found this in enter link description here
TxD means "Data to be transmitted over the comms link" - which will clearly be an input to the modem; Similarly, RxD means "Data that has been received from the comms link" - which will clearly be an output from the modem.
But I couldn't send or receive SMS using this configurations.
As I am new to this, It would be very helpful if anyone help on this.
Thank you in advance.