User's Manual

HC-08 BLUETOOTH UART COMMUNICATION MODULE USER MANUAL
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Send: AT+BAUD=4800,E
Return: OK4800,EVEN
UART baud rate modified for 4800bps, and even parity.
Send: AT+BAUD=？
Return: 4800,EVEN
View UART baud rate and parity bit.
9600bps baud rate following each packet please do not exceed the maximum
number of bytes to 500 bytes, 19200bps baud rate above each packet please refer to
the following table, have a certain time interval between data packets. The following
table is a variety of communication baud rate, the time interval of reference value:
baud rate (bps) 1200 2400 4800 9600 19200 38400 57600 115200
500 bytes time interval (ms) 6800 3600 2000 1000
300 bytes time interval (ms) 4200 2400 1200 600 400
100 bytes time interval (ms) 1500 800 400 160 100 120
80 bytes time interval (ms) 1000 650 320 120 80 60 100
60 bytes time interval (ms) 800 500 250 100 60 60 60 100
20 bytes time interval (ms) 200 100 50 20 20 20 20 20
Note:
1. The above is the measured data, the fastest speed transceiver theory total:2500
bytes/sec, suggested that the speed control in the 2000 bytes/sec.
2. Bytes of each packet, suggestion is an integer multiple of 20.
3. Module sends data automatically subcontracting is an integer multiple of 20 bytes.
Is to send a 100 bytes packet, will receive a plurality of packets at another end, each
data packet is an integer multiple of 20, the total number of bytes for the full 100 bytes.
⑪ Set connect ability
Set command: AT+CONT=x
Query command: AT+CONT=?
The X parameter functions are as follows:
Parameter Master role Slave role
0
（default）
Central
Can be connected, the connection
after entering ordinary transparent
transmission mode
Peripheral
Can be connected, the connection
after entering ordinary transparent
transmission mode
1
Observer
The module can not be connected to
other device, but will automatic scan
the HC-08 from the broadcast data
machine package, fixed 2 seconds
refresh time.
Broadcaster
Not connected with the master role,
but can be combined with low power
mode 3, the realization of broadcast
data packet send.