User's Guide

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LM074 SPP with GAP Central Application v1.1

ix. After the module responds to the command with “OK”, the module

sends the data to the remote BLE device.

x. If the remote device receives the data and sends feedback to the

LM074, that feedback is displayed on UART.

xi. E.g. report shows, “REP*:WRWORESP=1:0019:Success” which

indicates the data has been received by the remote device

successfully. 1 is the CID-given by module and 0019 is the

characteristic handle.

at*wrworesp=1,0019,05,12345at*wrworesp=1,0019,05,12345

REP*:WRWORESP=1:0019:Success

at*wrworesp=1,0019,10,12345abcdef!()12at*wrworesp=1,001

9,10,12345abcdef!()12

REP*:WRWORESP=1:0019:Success

3.8.4 “AT*WRCHARVAL”\r\n

i. Execution only command

ii. This command is used to send data to BLE device for the

characteristic which has properties as “Wr_req” i.e. 0x08.

iii. Command format is “AT*WRCHARVAL=conn-ID, char-Handle,

length, actual-bytes”.

iv. e.g. “at*WRCHARVAL=1,0019,10,12345abcdef!()12” command is

used to send data to 1

connected device, on characteristic 0019.

No of bytes to write are 16 (0x10) and actual bytes are

12345abcdef!()12.

v. As shown in the example command, no of bytes to transmit is hex

value

vi. As shown in the example command, actual data bytes are not

separated by comma. When the value 0x31 is sent i.e. ASCII 1 is

sent, the data buffer is copied and sent to remote device

transparently.

vii. Note : The actual data bytes to be sent should not have “\r\n” as

the data itself because it is the terminating string for AT command

parser.

viii. For command “AT*WRWORESP=conn-ID, char-Handle, length,

actual-bytes” module gives OK response if all the following

conditions are true:

a. connection ID is correct (if module is connected to 3 devices

and CID mentions 4, then it is invalid)

b. Characteristic handle has Wr_req properties

c. Value of “length” field is less than 21 i.e. (0x15).

d. Actual data bytes are same as value of “length” field.

ix. After module responds to this command as “OK”, module sends

the data to remote BLE device.