ANNA-B112 - System integration manual
UBX-18009821 - R09
System description
Page 16 of 66
C1-Public
GPIO pins
The ANNA-B112 module can provide up to 25 pins, which can be configured as general purpose input
or output. 8 GPIO pins are capable of handling analog functionality. All pins are capable of handling
interrupt.
Function
Description
Default
ANNA-B1 pin
Configurable
GPIOs
General purpose input
Digital input with configurable edge detection and interrupt
generation.
Any
General purpose output Digital output with configurable drive strength, pull-up, pull-down,
open-source, open-drain and/or slew rate.
Any
Pin disabled
Pin is disconnected from input buffers and output drivers.
All*
Any
Timer/ counter
High precision time measurement between two pulses/ Pulse
counting with interrupt/event generation.
Any
Interrupt/ Event trigger Interrupt/event trigger to the software application/ Wake up event.
Any
ADC input
8/10/12-bit analog to digital converter
Any analog
Analog comparator
input
Compare two voltages, capable of generating wake-up events and
interrupts
Any analog
PWM output
Output complex pulse width modulation waveforms
Any
Connection status
indication
Indicates if a BLE connection is maintained
BLUE**
Any
* = If left unconfigured
** = If using u-connectXpress software
Table 9: GPIO custom functions configuration
1.9.1
Analog interfaces
8 out of the 25 digital GPIOs can be multiplexed to analog functions. The following analog functions
are available for use:
•
1x 8-channel ADC
•
1x Analog comparator*
•
1x Low-power analog comparator*
*Only one of the comparators can be used simultaneously.
ADC
The Analog to Digital Converter (ADC) can sample up to 200 kHz using different inputs as sample
triggers. Table 10 shows the sample speed in correlation to the maximum source impedance. It
supports 8/10/12-bit resolution. Any of the 8 analog inputs can be used both as single-ended inputs
and as differential pairs for measuring the voltage across them. The ADC supports full 0 V to VCC
input range.
Table 10: Acquisition versus source impedance
ACQ [us]
Maximum source resistance [k
Ω
]
3
10
5
40
10
100
15
200
20
400
40
800
