TXD: sender, usually expressed as the sender, normal communication RXD must answer another equipment. RXD: receiving end, usually expressed as the receiver, the normal communication TXD must answer another equipment. When normal communication itself TXD pick up equipment RXD forever! Since collect spontaneous: normal communication TXD RXD connect other devices, so if you want to receive their send data as the name implies, is receiving themselves to send data, is directly connected to the RXD TXD itself, that is, used to test whether the sending and receiving of normal itself, is the most simple test method is the fastest, when problems arise first do this test to determine whether the product failure. Also known as the loopback test.

Jdy-33 Dual mode Bluetooth SPP Bluetooth SPP-C compatible with HC-05/06 slave Bluetooth 3.0 patch type

Jdy-33 Dual mode Bluetooth SPP Bluetooth SPP-C compatible with HC-05/06 bluetooth 3.0 pin type

Anti-reverse connection, Bluetooth serial transmission module, wireless SERIAL PORT HC-05 master and slave bluetooth expansion board

Spp-c Bluetooth serial adapter module group to replace HC-05/0

TXD: sender, usually expressed as the sender, normal communication RXD must answer another equipment. RXD: receiving end, usually expressed as the receiver, the normal communication TXD must answer another equipment. When normal communication itself TXD pick up equipment RXD forever! Since collect spontaneous: normal communication TXD RXD connect other devices, so if you want to receive their send data as the name implies, is receiving themselves to send data, is directly connected to the RXD TXD itself, that is, used to test whether the sending and receiving of normal itself, is the most simple test method is the fastest, when problems arise first do this test to determine whether the product failure. Also known as the loopback test.