80
www.lairdtech.com
Laird Technologies
BTM510/511
Bluetooth
®
Multimedia Module
Register GPIO
Default
Range
Comment
S650
0
0..1
Mode for GPIO Config Registers:
0 = no mask;
1 = enable i/o pin state mask
S651
GPIO1
0x0000
0..0xFFFF
GPIO Configuration Registers
S650 must be set to 0 to enable configu
-
ration access
Controls Pin State, Pin Direction, Pin
Inversion, Function Mapping Enable,
Function Mapping Select and Function
Mapping Code / av_operation_id.
See Table 3.37: GPIO Configuration
Register Field Descriptions
S652
GPIO2
S653
GPIO3
S654
GPIO4
S655
GPIO5
S656
GPIO6
S657
GPIO7
S658
GPIO8
S670
GPIO1..8
0x0000
0..0xFF
Read/Write all GPIOs in one atomic step
(Write operation only affects GPIOs con
-
figured as outputs)
0x0001: GPIO1
0x0002: GPIO2
0x0004: GPIO3
0x0008: GPIO4
0x0010: GPIO5
0x0020: GPIO6
0x0040: GPIO7
0x0080: GPIO8
Table 3.45: GPIO S Registers
6.1 Profile Specific GPIO Function Mapping
In some Bluetooth profiles it makes sense to map GPIOs to certain functions, e.g., Volume Up/Down
(HFP/A2DP), answer call (HFP), reject call (HFP) etc. Therefore, new S registers 651 to 663 will be
introduced, corresponding to GPIO1 to GPIO13. If a function mapping code is set to one of those
registers and function mapping enabled (FME=1), the appropriate Pin will carry out the assigned
function and will not be available anymore as GPIO.
The logical level of a GPIO can be inverted by setting the appropriate INV-flag of the appropriate
GPIO Configuration Register.
Restrictions can apply if certain GPIOS will be reserved for other functions in future, e.g., Wi-Fi
coexistence signalling.
Function Mapping Code
Value
Comment
Volume Up
0x01
A2DP,HFP: adjust volume locally
Volume Down
0x02
A2DP,HFP: adjust volume locally
Mute
0x03
A2DP,HFP
Answer Incoming Call
0x04
HFP
Reject Call or Hang Up
0x05
HFP
Reject Call
0x06
HFP
Hang Up
0x07
HFP
Table 3.46: GPIO Function Mapping Codes
AT COMMAND SET
REFERENCE