Rainbow Electronics GM862-GPS - Manual (Page 82)

GM862-GPS Software User Guide
1vv0300729 Rev. 5 - 05/07/07
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3.6.2 GPIO pin use
After having set-up the GPIO pin direction you can query the input status of an INPUT pin or set the
output status of an OUTPUT pin.
3.6.2.1 Querying GPIO pin status
To query for the pin status:
•
Send command AT#GPIO=<pin>,2<cr>
where:
<pin> is the GPIO pin number at which the command applies:
1 – GPIO1 7 – GPIO7
2 – GPIO2 8 – GPIO8
3 – GPIO3 9 – GPIO9
4 – GPIO4 10 – GPIO10
5 – GPIO5 11 – GPIO11
6 – GPIO6 12 – GPIO12
13 – GPIO13
•
wait for response in the format:
#GPIO: <dir>,<stat>
OK
where:
<dir> - GPIO<pin> direction setting
<stat> - status of the pin
0 - LOW
1 - HIGH
NOTE: In case the GPIO pin direction is set to ALTERNATE FUNCTION (2), then the reported
<stat> has no meaning and shall not kept as valid, but shall be threaten as a dummy value.
TIP: The query reports depending on the pin direction:
- the read pin status in case the direction is input;
- the previously set pin status in case the direction is output.
In any case, you can know if the pin at the query moment is high or low and the pin direction.
For example:
1- Let's assume you want to query the GPIO3 pin for its status:
command:
AT#GPIO=3,2<cr>
response:
#GPIO: 0,1
OK
In this case, the GPIO3 pin was set in input direction and its status has been measured to be HIGH.