Conncet Bluetoth module HC-05 to Arduino Uno Using UART Usb to enter in AT command

Question

I have connected Arduino Rx(pin 0) to Bluetooth module Rx pin. Tx od Arduino to Tx of Bluetooth . I am able to send command to Bluetooth module using Serial Monitor of Arduino on my PC.

I have uploaded the empty code in Arduino.

I want to know why we connected Tx to Tx and Rx to Rx i.e one to one connection?

If I send command "AT" from my PC using serial Monitor of Arduino , How is it flowing to Bluetooth module.

Why not we connect Rx to Tx pin in AT Mode of Bluetooth module?

Pls explain using diagram.

Answer 1

By using SoftSerial you can connect the HC-05 module to another pin than D0 and D1. Example connect HC-05 to D2 and D3 and define SoftSerial to use D2 and D3.

--------- ----------- ------
| HC-05 +---(SoftSerial)---(D2/3)+ Arduino +(D0/1)---(Serial USB)---+ PC |
--------- ----------- ------