Siemens AC75 - Manual (Page 508)

AC75 AT Command Set
20. GPIO Commands
s
AC75_ATC_V01.002 Page 508 of 569 10/30/06
Confidential / Released
20. GPIO Commands
This chapter describes the AT commands needed to access and configure the GPIO pins of the AC75.
Please also refer to [2] for electrical specifications of the GPIOs and their signal states after startup and during
application.
Except for the pulse counter commands, usage of all GPIO commands is restricted to the same interface where
the GPIO driver was openend with
AT^SPIO
. Any attempt to access GPIOs from another interface will be denied
with an error message.
When the AC75 starts up, all GPIO pins are set to high-impedance state after initializing. Therefore, it is recom-
mended to connect pull-up or pull-down resistors to all GPIO pins you want to use as output. This is necessary
to keep these pins from floating or driving any external devices before all settings are done by AT command (at
least
AT^SPIO
,
AT^SCPIN
), and after closing the GPIOs again.
20.1 AT^SPIO General Purpose IO Driver Open/Close
The
AT^SPIO
write command opens and closes the general purpose IO driver. The command must be executed
before any other GPIO command can be used. After closing the driver, all pins used (i.e. opened) will be put into
high impedance state (inputs) with no internal pull up or down.
The command does not reserve any general purpose IO pin, only the drivers required for GPIO pin management
will be loaded.
Syntax
Parameter Description
0 Close General purpose IO driver
1 Open General purpose IO driver
Test Command
AT^SPIO=?
Response(s)
^SPIO:
(list of supported
<mode>
s)
OK
Write Command
AT^SPIO= <mode>
Response(s)
OK
ERROR
+CME ERROR: <err>
Reference(s) PIN ASC0 ASC1 USB MUX1 MUX2 MUX3 Charge
4
Last
SIEMENS - + + + + + + - + -
<mode>
(num)