2.4GH
Z
B
LUETOOTH
T
RANSCEIVER
M
ODULE
P
ROGRAMMING
G
UIDE
BRM01
GPIO Set-up
This command configures the GPIO functions for the BRM. Use this command to change the default settings
for the GPIO pins if used.
Command Code
(1 byte)
“G”
Parameter 1 – Direction
(2 bytes C0-FF)
“xx”
Parameter 2 – Function
(2 bytes 00-FF)
“xx”
Parameter 3 – Initialise
(2 bytes 00-FF)
“xx”
Direction Parameter
These two BCD bytes represent a bit mask to define which of the GPIO pins are inputs or outputs. Bits 0 to
5 control the GPIO pins GPIO0 to GPIO5 respectively. Bits 6 and 7 are reserved and should be set to ‘1’.
The GPIO pin will behave as an input and when the direction bit is set to ‘1’ and an output when set to a ‘0’.
By default GPIO pins are inputs. An example is given below:
Direction Value
FF
C3
GPIO5
Input
Output
GPIO4
Input
Output
GPIO3
Input
Output
GPIO2
Input
Output
GPIO1
Input
Output
GPIO0
Input
Output
Function Parameter
These two BCD bytes control the function of the GPIO pins. Valid codes are shown below;
Function Value
06
0E
0F
05
0D
0C
03
02
GPIO5
D I/O
D I/O
D I/O
D I/O
D I/O
ADC
ADC
ADC
GPIO4
D I/O
D I/O
D I/O
D I/O
D I/O
D I/O
D I/O
D I/O
GPIO3
D I/O
D I/O
REF+
REF+
REF+
REF+
REF+
ADC
GPIO2
D I/O
D I/O
REF-
D I/O
REF-
REF-
ADC
ADC
GPIO1
D I/O
D I/O
D I/O
ADC
ADC
ADC
ADC
ADC
GPIO0
D I/O
ADC
ADC
ADC
ADC
ADC
ADC
ADC
Initialise Parameter
This parameter defines the initial Logic State of each GPIO pin when it is defined as an output. Values above
0x3F are not allowed. The two BCD bytes represent the bit mask of the 6 GPIO lines as given in the example
below:
Initialise Value
3F
26
GPIO5
High
High
GPIO4
High
Low
GPIO3
High
Low
GPIO2
High
High
GPIO1
High
High
GPIO0
High
Low
Response Code
Status Code *
(1 byte)
(2 bytes 0-9, A-F)
“G”
“xx”
*See Status Codes for meanings
DS361-3 Dec 03
©2003 Reg. No. 227 4001, England
Page 6
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