User's Manual

Enhanced Class 1 Bluetooth v2.1 Module
User’s Guide
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www.lairdtech.com/wireless
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CONN-GUIDE-BT740_v0.2
4.4 General Purpose I/O and ADC
4.4.1 GPIO
Laird provides seven lines of programmable bi-directional input/outputs (I/O) that can be accessed either
via the UART port or Over The Air (OTA) from a second Bluetooth unit. These can be used as data inputs
or to control external equipment. By using these in OTA mode, a BT730 module can be used for control
and data acquisition without the need for any additional host processor. Each of the GPIO[3:9] ports can
independently configure to be either an input or output. A selection of ports can be accessed
synchronously.
The ports power from VCC. The mode of these lines can be configured and the lines are accessed via S
Registers 623 to 629.
4.4.2 ADC
The BT740 provides access to two 8-bit ADCs (Analogue 0 and 1). These provide an input range of 0 mV
to 1,800 mV, which are read using the S registers 701 and 702.
Suitable external scaling and over-voltage protection should be incorporated in your design. The module
provides five samples per second at the UART with a baud rate of 115,200 or above.