Chapter 14 – Specific AT Commands
Multi-Tech Systems, Inc. CDMA Wireless AT Commands - PN S000294C 109
Configure LED Indicator +CLED Description: This command is used to configure GPIO 41 and GPIO 54 for general purpose use. The
default use of these two GPIO’s is to drive LED indicators on the Developer Kit board. This
command allows a user application to disable this default behavior. When disabled, the user
application has full control over the state of these GPIO’s. The modem operating software
will be prevented from change them for operational status indications.
The byte value specified with the +CLED command is a bitmap where bit 0 configures
LED1/GPIO 41 and bit 1 configures LED2/GPIO 54. Bit positions 2 through 7 are ignored.
The state of the +CLED specified control bits is not persistent. Both bit positions are always
set active (1) during boot resulting in LED status indicator operation. The +CLED command
must be used by the user application after each boot if GPIO 41 or GPIO 54 are used for
other purposes.
Values: <bitmap value>
bit 0: 0 = GPIO 41 selected; 1 = LED1 selected.
bit 1: 0 = GPIO 54 selected; 1 = LED2 selected.
bit 2 – bit7: Reserved
Syntax: Command syntax: AT+CLED=<bitmap value>
Command Possible Responses
AT+CLED?
Note: Display current settings.
CLED: 3
OK
Note: Both GPIO’s are used for modem operational
status indicators.
AT+CLED=?
Note: Display valid parameter range.
CLED: (0-3)
OK
AT+CLED=1
Note: Set bit 1 to inactive and bit 0 to
active.
AT+WIOW=54,0
Note: Set GPIO state.
AT+WIOR=41
Note: Read state of LED1 indicator.
OK
Note: GPIO 54 available, LED1 used for modem
status.
OK
Note: Set GPIO 54 to 0.
+WIOR: 1
OK
Note: Read current state of LED1 indicator
AT+CLED=2
Note: Set bit 1 to active and bit 0 to
inactive.
AT+WIOW=41,1
Note: Set GPIO state.
AT+WIOW=54,1
Note: Set LED2 state.
OK
Note: LED2 used for modem status, GPIO 41
available.
OK
Note: Set GPIO 41 to 1.
OK
Note: LED2 indicator set to “on”. LED on/off state may
change due to modem status indication.