Chapter 13 – Specific AT Commands
Multi-Tech Systems, Inc. Wireless GSM/GPRS AT Commands (Document Number S000293I) 115
Input/Output Management +WIOM
Description: This command sets the default GPIO’s configuration (input or output) after reset, and each GPIO default
value (if set as an output) after reset.
Notes:
• This command is allowed only on a GPIO not allocated by the Open-AT embedded application or
for bus operations.
• When UART is activated, GPIOs 0 and 5, GPO2 and GPI are not available anymore. When you
try to do writable or readable operations on these I/O, CME ERROR: 3 will be returned. This
applies for modems running AT X50 software and supporting the multi-UART feature.
• When the BT chip is switched on, the GPIO5 is not available anymore. It is not possible to
change the state of the GPIO using this command.
Values: <GpioDir> Bit table parameter indicating each GPIO direction.
0 Input
1 Output. Default.
Default value: 2047 (all GPIOs set as outputs).
<GpioVal> Bit table parameter indicating each output-configured GPIO value (each bit gives the
corresponding GPIO default value).
0 Reset. Default.
1 Set
The GPIOs set as inputs by the <GpioDir> parameter are not affected by the value set by the
<GpioVal> parameter.
Notes:

• <GpioDir> bit values for GPI and GPO are ignored.

• <GpioVal> bit values for GPI are ignored.

Syntax: Command syntax: AT+WIOM=[<GpioDir>],[<GpioVal>]
Command Possible responses
AT+WIOM? +WIOM: 2047,0
OK
On reset, all GPIOs are set to 0, as an output
AT+WIOM=? +WIOM: (0-2047),(0-2047)
OK
Range allowed for the parameters.
AT+WIOM=254
Set GPIO 0 as an input, and all others as outputs OK
AT+WIOM=,128
Set GPIO 3; default output value to 1 OK
AT+WIOM=,128
Note: Set GPIO 8 or GPIO12 or GPIO7; default
output value to 1
OK