User's Guide

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LM074 SPP with GAP Central Application v1.1
3.7 BLE read data from Characteristic:
3.7.1 “AT*RDCHARVAL”\r\n
i. Execution only command
ii. This command is used to read data from the BLE device for the
characteristic which has properties as read “Rd” i.e. 0x02.
iii. The command format is “AT*RDCHARVAL=conn-ID, char-Handle”.
iv. e.g. “at*rdcharval=1,0003” command is used to read data from 1
st
connected device, for characteristic 0003.
v. The module shall output an OK response if the CID and the Char-
handle is correct.
vi. After the module gives OK response to read command, module
shows data received from remote device as a report.
vii. E.g. “REP*:RDCHARVAL=1:Rcvd_Bytes:0010 LM Serial Server” is
a report of read data for characteristic 0003.
viii. Report shows connection ID as 1, Received bytes as 0x10 i.e. 16
bytes, and the actual bytes are “LM Serial Server”.
ix. If module receives an error response it is reported to user with the
error code.
x. Users can refer to error codes as mentioned in the appendix
section.
at*rdcharval=1,000cat*rdcharval=1,000c
OK
REP*:RDCHARVAL=0001:Err_code:02
xi. Below show some reference reports for read command.
at*rdcharval=1,0003at*rdcharval=1,0003
OK
REP*:RDCHARVAL=1:Rcvd_Bytes:0010
LM Serial Server
at*rdcharval=1,0005at*rdcharval=1,0005
OK
REP*:RDCHARVAL=1:Rcvd_Bytes:0002
at*rdcharval=1,000aat*rdcharval=1,000a
OK
REP*:RDCHARVAL=1:Rcvd_Bytes:0016
CSR-GATT-SERVER-MODEL-
at*rdcharval=1,000cat*rdcharval=1,000c
OK
REP*:RDCHARVAL=0001:Err_code:02
xii. Above screenshots are taken on Hercules software on Windows
PC, it does not show non-printable characters in received