User's Manual

GPIO3 is high when Server or Client is connected.

GPIO3 is low when Server or Client is disconnected.

1.5.2.

Low-power operation (GPIO4)

The BT always enters the low-power mode in a situation where it is available.

In the low-power mode, there may occur an omission of data transmitted

using UART in the HOST.

When data to be transmitted in AT command or with the Remote devices

is sent to UART, be sure that a low-power GPIO4 must be kept high.

While GPIO is kept HIGH, The BT will not enter the low-power mode. If

GPIO is kept LOW, the BT will immediately enter the low-power mode,

but this case may cause problems in the UART communication.

1.5.3.

Initialization to Factory Settings and Disconnection (GPIO9)

GPIO9 port has a default setting input in advance. When high values are

kept more than 4 seconds, make a + OK response before returning them

to the factory setting state. Also, when HIGH values are input during the

connection, disconnection is possible.

REQUEST (HOST → BT) Protocol Summary

Protocol Description Remark

AT +OK request <Server/Client Role>

ATZ Module reset <Server/Client Role>

AT&F Initialize values to be changed in the current module

to factory settings before resetting them

AT+VER? Request the version of the firmware applied to the

current module.

AT+INFO? Request the Bluetooth address, Device Name and

Role information of the current module.

e.g.)

74:F0:7D:B0:12:12,BoT,SERVER[PERIPHERAL]

AT+UART=xxxx Used when the UART Baudrate is changed

2400, 9600, 19200, 38400, 57600, 115200, 230400

AT+ROLECHANGE Change the role of the current device. <Server/Client Role>

AT+SERVER=role If the device operates in the Server mode, the

operation will be decided depending on the role.

: role=B – Broadcaster

: role=P - Peripheral