Silicon Labs DKBT User Manual

DKBT BLUETOOTH DUAL MODE DEVELOPMENT KIT

USER GUIDE
Wednesday, 25 November 2020

Document Version : 1.2

VERSION HISTORY

Silicon Labs

Date Edited Comment

1.0 First release of document

1.1 Minor changes

1.2

Renamed "Smart Ready" to "Dual Mode" and "Classic" to "BR/EDR"
according to the official Bluetooth SIG nomenclature.

TABLE OF CONTENTS

Silicon Labs

Introduction 5 1

1.1 Package contents 5

DKBT overview 6 2

2.1 DKBT functional block diagram 7

Interpreting the silk screens 8 3
Power supply options 9 4

4.1 Powering with a 1.5 V AAA battery 9

4.2 Powering through USB 9

4.3 Powering using an external power supply 9

Measuring the current consumption 11 5

5.1 Measuring average currents with a DMM 13

5.2 Measuring sleep currents with a DMM 13

5.3 Measuring peak currents with an oscilloscope 14

Peripherals 15 6

6.1 Buttons and LEDs 16

6.2 Potentiometer 16

6.3 Current sense and 0mA reference 16

6.4 LCD display 17

6.5 SPI accelerometer 18

6.6 I2C altimeter 19

Related documentation 20 7
Contact information 21 8

Introduction 1

Silicon Labs

This document describes the DKBT Bluetooth Dual Mode developm ent kit hardware and contains useful
information about the development kit hardware as well as instructions on how to use it.

DKBT Bluetooth Dual Mode enables easy evaluation of Bluegiga Bluetooth Dual Mode modules and
serves as a platform for developing Bluetooth Dual Mode applications.

1.1 Package contents

DKBT is delivered with the parts shown in Figure 1 below.

Figure 1: DKBT development kit cont ents

5

DKBT overview 2

Silicon Labs

This section introduces the functional la yout of the DKBT main board and the BT121 Bluetooth Dual Mode
module carrier board.

An overview of the functional layout of DKBT board and BT121 carrier b oard is shown in Figur e 2 below. The
corresponding functional block diagram is shown in Figure 3 on the following page.

Figure 2: DKBT development kit overview

6

2.1 DKBT functional block diagram

Silicon Labs

The DKBT functional block diagram with essential components and interconnections is shown in Figure 3
below.

Figure 3: DKBT functional block diagram

BT121 Bluetooth Dual Mode module provides vari ous serial interfaces (SPI , I2C, U ART) for connectin g to
peripherals and/or for communicating with other devices such as h ost processors. The SPI bus ( Alt 1 and Alt

2) on the DKBT is connected to an accelerometer and to an LCD display while the I
connected to a precision altimeter/pressure sensor. The accelerometer and altimeter/pressure sensor both
have two interrupt outputs, which are exposed as pads on the DKBT main board.

The DKBT main boar d contains also five push-buttons and five LEDs which c an be controll ed by GPIO of the
BT121. Depending on how the firmware defines the corresponding GPIO pin on the BT121 module, the
switches may be used as inputs. In such cases the correspond ing LED will turn ON when the push-button is
pressed dow n. If the pin has been configured as an output the LE D acts as a visual indicator of the output
state of that part icular GPIO pin. LED’s are b uffer ed by a tr ansistor to pr event loading of the GPIO pins of the
module.

Current measur ement circuitry of f er s the means to measure the peak and a ver a g e current consumption of th e
module or of the whole DK BT board. A BNC c onnector driven by a fast buffer amplifier enables peak current
measurements with the help of an oscilloscope

The UART of the BT121 is connected through a USB-TO-UART converter to a USB c onnec tor which provides
easy connectivity to a PC.

7

2

C bus on the DKBT is