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Dialog Semiconductor DA14681 Hardware Manual

Wearable development kit
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User Manual
DA14681 Wearable Development
Kit Hardware Manual
UM-B-077

Abstract

This document describes the hardware design of the DA14681 Wearable Development Kit, which is
based on the Dialog Semiconductor DA14681 Bluetooth® low energy SoC. This wearable module
includes a geomagnetic sensor, an accelerometer, a combined environmental sensor that can sense
temperature, pressure and humidity levels, a heart rate monitor, and NFC functionality. It can display
environmental readings as well as health data such as step count, distance traveled, calories burned
and heart rate. All these functions are combined in a wearable-like watch, enabling the user to
physically wear it and keep a track of his day-to-day activities.

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Summary of Contents for Dialog Semiconductor DA14681

  • Page 1: Abstract

    UM-B-077 Abstract This document describes the hardware design of the DA14681 Wearable Development Kit, which is based on the Dialog Semiconductor DA14681 Bluetooth® low energy SoC. This wearable module includes a geomagnetic sensor, an accelerometer, a combined environmental sensor that can sense temperature, pressure and humidity levels, a heart rate monitor, and NFC functionality.

  • Page 2: Table Of Contents

    Revision History ..........................46 Figures Figure 1: Top Level Block Diagram of the DA14681 Wearable Reference Design ......7 Figure 2: DA14681 Wearable Reference Design Rev.E (Motherboard) - Top view ......8 Figure 3: DA14681 Wearable Reference Design Rev.E (Motherboard) - Bottom view ......8 Figure 4: DA14681 System Schematic ....................

  • Page 3: Tables

    Figure 22: Ceramic Antenna PCB Footprint and Mechanical Specifications ........26 Figure 23: HRM Schematic ......................... 28 Figure 24: DA14681 Wearable Reference Design - BLE SoC, QSPI, GPIO Expander Schematic ..29 Figure 25: DA14681 Wearable Reference Design - Peripherals Schematic ........30 Figure 26: DA14681 Wearable Reference Design - Sensors Schematic ...........
  • Page 4 UM-B-077 DA14681 Wearable Development Kit Hardware Manual Table 14: Electrical Characteristics – IR LED ..................27 Table 15: Electrical Characteristics – Green LED ................28 Table 16: NFC Module Pin Description (Partial) ................. 33 Table 17: Current Consumption of Wearable Reference Design Sensors and Peripherals ....41 User Manual Revision 1.2...

  • Page 5: Terms And Definitions

    UM-B-077 DA14681 Wearable Development Kit Hardware Manual Terms and Definitions APDU Application Protocol Data Unit Bluetooth low energy Communication Interface Board Direct Current Resistance DCXO Digitally Controlled Crystal Oscillator Heart Rate Monitor hardware Infrared Inverted-F Antenna Internet of Things JTAG...

  • Page 6: System Overview

    The DA14681 wearable reference design described in this manual, is a low power and compact prototype that can easily fit in a suitable enclosure to form a wearable smart watch. The PCB layout...

  • Page 7: Figure 1: Top Level Block Diagram Of The Da14681 Wearable Reference Design

    USBN Connector Dyna-Image VBUS LDR2 DI5115 LDR1 VBAT LiPoly 2xIR Serial 190mAh Discrete Interface solution Figure 1: Top Level Block Diagram of the DA14681 Wearable Reference Design User Manual Revision 1.2 06-Apr-2017 © 2017 Dialog Semiconductor CFR0012 7 of 47...

  • Page 8: Figure 2: Da14681 Wearable Reference Design Rev.e (Motherboard) - Top View

    UM-B-077 DA14681 Wearable Development Kit Hardware Manual Vibrator Push Button Figure 2: 680-RD-wearable-mb_vE- Top view Debugging port Figure 3: 680-RD-wearable-mb_vE- Bottom view User Manual Revision 1.2 06-Apr-2017 © 2017 Dialog Semiconductor CFR0012 8 of 47...

  • Page 9: Da14681 Reference Design - Motherboard

    (RAM, ROM) or non- volatile memory (OTP or external Quad-SPI Flash memory for DA14681). The advanced power management unit of the DA14681 enables it to run from primary and secondary batteries, as well as provide power to external devices.

  • Page 10: Debugging Section

    2 mA. When in sleep mode the 1.8 V is supplied directly from the LDO, while in active mode from a DC-DC converter. V12: Power rail that supplies the digital core of the DA14681 and delivers up to 50 mA at 1.2 V when in active mode. A 4.7 F decoupling capacitor (C6) is used (0402 package, 6.3 V).

  • Page 11: Figure 6: Idc-10 Cable Between Interface Board And Wearable Reference Design Board

    ● Connectivity of PC to the DA14681 JTAG port. ● Connectivity of PC to the DA14681 UART port (full UART is possible but it must be enabled on the PC driver). ● Hardware RESET capability through the T_RESET signal. Note that the signal T_RESET is active low and therefore is inverted by U7 before reaching the RST pin on the DA14681.

  • Page 12: Figure 7: Idc-10 Cable Between Interface Board And Wearable Reference Design Enclosure

    UM-B-077 DA14681 Wearable Development Kit Hardware Manual Figure 7: IDC-10 Cable between Interface Board and Wearable Reference Design Enclosure User Manual Revision 1.2 06-Apr-2017 © 2017 Dialog Semiconductor CFR0012 12 of 47...

  • Page 13: Qspi Data Flash Memory

    Interface (QPI), Serial Clock, Chip Select, Serial Data I/O0 (DI), I/O1(D0), I/O2 (/WP) and I/O3(/HOLD). QSPI is supplied from the V18 voltage rail. The same supply voltage is connected to the DA14681 VDDIO pin. Figure 8: QSPI Data Flash Schematic...

  • Page 14: Da14681 Pin Assignment

    0.5 W Drive Level (PD) 4.1.4 DA14681 Pin Assignment Table 4 shows the pin assignment and related pin names on the aQFN60 package of the DA14681. Table 4: 680-RD-wearable-mb_vE Pin Assignment DA14681 AQFN60 Pin Name Reference Design Signal Section P0_0...
  • Page 15 UM-B-077 DA14681 Wearable Development Kit Hardware Manual DA14681 AQFN60 Pin Name Reference Design Signal Section P3_1 SPI_MISO Sensors P3_2 SPI_SCK Sensors P3_3 BMI_nCS Sensors P3_4 BME_nCS Sensors P3_5 7816CLK P3_6 BMI_INT Sensors P3_7 VDDSE P4_0 7816IO (URX side) P4_1 VIB_EN...

  • Page 16: Gpio Expander

    UM-B-077 DA14681 Wearable Development Kit Hardware Manual GPIO Expander Due to the high GPIO demand in this reference design a GPIO expander was necessary. The component used is the low power I2C controlled FXL6408UMX from Fairchild. It uses both power rails of 1.8 V and 3.3 V while its power consumption remains very low at only 1.5 A (Sleep current).

  • Page 17: Microphone

    Knowles is a miniature, high performance, low power, top port silicon digital microphone with a single-bit PDM output. In this reference design the microphone’s data signal is driven by the GPIO P0_7 from the DA14681 SoC. Its power consumption during sleep is only 4.6 A.

  • Page 18: Li-Po Battery

    UM-B-077 DA14681 Wearable Development Kit Hardware Manual Li-Po Battery The battery used is a rechargeable Li-Po from HHS, which is available with capacities of 190 mAh and 250 mAh. Table 6 shows the battery dimensions. Table 6: Battery Dimensions Capacity (mAh)

  • Page 19: Figure 12: Li-Po Battery Charging/Discharging Curves

    UM-B-077 DA14681 Wearable Development Kit Hardware Manual Figure 12: Li-Po Battery Charging/Discharging Curves Figure 13: Technical Characteristics of the 190 mAh Li-Po Battery The LiPo battery discussed is equipped with a protection circuit module (PCM). The PCM will generally provide the battery with overcharge/discharge protection, short circuit protection, current limitation, and voltage and current balancing in each cell.

  • Page 20: Lcd Display

    The clock frequency in this case is set to 64 Hz and it is fed into the display via the RTC_SQW pin of the RTC module. By default this clock is provided by the RTC, alternatively it can also be supplied by the DA14681 SoC. Figure 15: TFT Display Connector Schematic User Manual Revision 1.2...

  • Page 21: Figure 16: Tft Display

    UM-B-077 DA14681 Wearable Development Kit Hardware Manual The TFT display is powered by the V33 output voltage rail of the DA14681 BLE SoC. Main features include: ● Display control with serial data signal communication ● Internal 1-bit memory within the panel for data memory ●...

  • Page 22: Da14681 Wearable Reference Design Sensors

    3 A is suspend mode. The BMI160 module is connected to the DA14681 via an SPI interface. In this reference design the secondary I2C interface of the BMI160 is used to connect the BMM150 (magnetometer) to the BMI160 in slave mode, in order to acquire the data in synchronized form.

  • Page 23: Bmm150 - Magnetometer

    The magnetometer is not connected directly to the DA14681 but only via the BMI160 and through the I2C interface. The current consumption is 500 A in normal mode, while in sleep mode it is 3 A.

  • Page 24: Bme280 - Environmental Sensor

    The BME280 is connected to the DA14681 BLE using an SPI interface. The current consumption in normal mode is 3.6 A, while in sleep mode it is 0.1 A.

  • Page 25: Rtc - Real Time Clock

    Abracon, which includes on-chip oscillators to provide minimum power consumption, full RTC functions including battery backup and programmable counters and alarms for timer and watchdog functions, and an I2C interface for communication with the DA14681. 21. The power consumption during sleep mode is 0.34 A.

  • Page 26: Antenna

    UM-B-077 DA14681 Wearable Development Kit Hardware Manual Antenna A ceramic type of chip antenna (2450AT18A100 from Johanson) is currently used in the wearable reference design. This selection has been made for the following advantages: ● SMD miniature type of manufacturability ●...

  • Page 27: Heart Rate Monitor (Hrm)

    Wrist-based HRM technology introduces a new way of biometric monitoring by providing a more convenient and comfortable way to measure heart rate, rivalling the accuracy of chest-strap-based designs. The DA14681 wearable reference design incorporates such a wrist-based heart rate monitor based on the DI5115 HRM module from Dyna Image.

  • Page 28: Figure 23: Hrm Schematic

    UM-B-077 DA14681 Wearable Development Kit Hardware Manual Table 15: Electrical Characteristics – Green LED Parameter Symbol Color Min. Typ. Max. Unit Forward Voltage Green Luminous Intensity Green 1070 μA Reverse Current Green λ Peak Wavelength Green λ Dominant Wavelength Green Δλ...

  • Page 29: 4.10 Da14681 Wearable Reference Design- Motherboard Schematics

    UM-B-077 DA14681 Wearable Development Kit Hardware Manual 4.10 DA14681 Wearable Reference Design- Motherboard Schematics Figure 24: 680-RD-wearable-mb_vE - BLE SoC, QSPI, GPIO Expander Schematic User Manual Revision 1.2 06-Apr-2017 © 2017 Dialog Semiconductor CFR0012 29 of 47...

  • Page 30: Figure 25: Da14681 Wearable Reference Design - Peripherals Schematic

    UM-B-077 DA14681 Wearable Development Kit Hardware Manual Figure 25: 680-RD-wearable-mb_vE - Peripherals Schematic User Manual Revision 1.2 06-Apr-2017 © 2017 Dialog Semiconductor CFR0012 30 of 47...

  • Page 31: Figure 26: Da14681 Wearable Reference Design - Sensors Schematic

    UM-B-077 DA14681 Wearable Development Kit Hardware Manual Figure 26: 680-RD-wearable-mb_vE - Sensors Schematic User Manual Revision 1.2 06-Apr-2017 © 2017 Dialog Semiconductor CFR0012 31 of 47...

  • Page 32: Da14681 Reference Design - Daughterboard

    (SE). The communication between the NFC module and the host (DA14681) is established via the ISO 7816 standard. The Card Emulation (contactless) mode is implemented via the RF Communication Mode and is executed by the analog front-end of the NFC module.

  • Page 33: Figure 28: Nfc Module Schematic

    UM-B-077 DA14681 Wearable Development Kit Hardware Manual Figure 28: NFC Module Schematic The LA66002 is a boosted NFC module providing hassle free and immediate connectivity, unlike traditional NFC devices that sometimes are unable to establish immediate connection. So it works much better in payment or in transport infrastructure applications where the transactions are faster.

  • Page 34: Figure 29: Block Diagram Of The Host Communication Mode Implementation

    RST line. Here, a 4 MHz clock is provided by the DA14681. Upon powering up and entering host mode successfully, the NFC module will output an Answer to Reset (ATR) message, after which protocol parameter negotiation and communication with the host can be initiated.

  • Page 35: Figure 31: Voltage Levels Of The Nfc Module Pins - Rf Communication Mode

    UM-B-077 DA14681 Wearable Development Kit Hardware Manual Figure 31: Voltage Levels of the NFC Module Pins – RF Communication Mode The NFC module runs its own dedicated secure operating system and applications, and communicates with the host or reader via standard and application specific APDU (Application Protocol Data Unit) commands.

  • Page 36: Capacitive Touch And Proximity Controller

    Figure 32: Capacitive Touch Controller Schematic The capacitive touch sensors help the user to navigate through the various sensor readings that appear on the TFT display. The touch sensor is accessible by the DA14681 via the I2C interface. The PCB touch pads are shown in...

  • Page 37: Figure 34: Pcb Touch Pad Recommended Shapes

    UM-B-077 DA14681 Wearable Development Kit Hardware Manual Figure 34: PCB Touch Pad Recommended Shapes Figure 35: 680_RD_WEARABLE_PCB_TOUCH_BUTTONS_2X_VC -Top View Capacitive Module Controller LA66002 SX9300 Figure 36: 680_RD_WEARABLE_PCB_TOUCH_BUTTONS_2X_VC - Bottom View Figure 37: Touch Pad Daughterboard Attached to the Motherboard User Manual Revision 1.2...

  • Page 38: Figure 38: Da14681 Wearable Reference Design - Daughterboard Schematic

    UM-B-077 DA14681 Wearable Development Kit Hardware Manual Figure 38: 680_RD_WEARABLE_PCB_TOUCH_BUTTONS_2X_VC - Daughterboard Schematic User Manual Revision 1.2 06-Apr-2017 © 2017 Dialog Semiconductor CFR0012 38 of 47...

  • Page 39: Wearable Reference Design - Pcb

    UM-B-077 DA14681 Wearable Development Kit Hardware Manual Wearable Reference Design - PCB Figure 39: 680-RD-wearable-mb_vE – Motherboard (Top View) Figure 40: 680-RD-wearable-mb_vE – Motherboard (Bottom View) User Manual Revision 1.2 06-Apr-2017 © 2017 Dialog Semiconductor CFR0012 39 of 47...

  • Page 40: Figure 41: Da14681 Wearable Reference Design - Daughterboard (Top View)

    UM-B-077 DA14681 Wearable Development Kit Hardware Manual Figure 41: 680_RD_WEARABLE_PCB_TOUCH_BUTTONS_2X_VC – Daughterboard (Top View) Figure 42: 680_RD_WEARABLE_PCB_TOUCH_BUTTONS_2X_VC – Daughterboard (Bottom View) User Manual Revision 1.2 06-Apr-2017 © 2017 Dialog Semiconductor CFR0012 40 of 47...

  • Page 41: Power Consumption Measurements

    The current measurements in this section have been obtained using the Agilent N6705B DC power analyzer. Figure 43 presents a simplified block diagram of the DA14681 wearable reference design, showing the various test points where the actual current measurements have been taken for each sensor and peripheral of the system.

  • Page 42: Figure 44: Actual Current Consumption Waveform (Sleep Mode) From Dc Power Analyzer

    UM-B-077 DA14681 Wearable Development Kit Hardware Manual Figure 44: Actual Current Consumption Waveform (Sleep Mode) from DC Power Analyzer The average current consumption in Advertising mode is approximately 250 A. When the wearable device is connected to a host this goes up to 550 A (advertising pulse period: 1 s).

  • Page 43: Wearable Reference Design Enclosure

    UM-B-077 DA14681 Wearable Development Kit Hardware Manual Wearable Reference Design Enclosure The main purpose of this wearable reference design was to fit inside a wrist watch type housing, so it can be used as fitness equipment. This section presents the enclosure that was developed for the wearable reference design.

  • Page 44: Figure 47: Actual Enclosure - Top View

    UM-B-077 DA14681 Wearable Development Kit Hardware Manual Figure 47: Actual Enclosure – Top View Figure 48: Actual Enclosure – Bottom View User Manual Revision 1.2 06-Apr-2017 © 2017 Dialog Semiconductor CFR0012 44 of 47...

  • Page 45: Figure 49: Wearable Watch Placed On The Left Wrist

    UM-B-077 DA14681 Wearable Development Kit Hardware Manual Figure 49: Wearable Watch Placed on the Left Wrist User Manual Revision 1.2 06-Apr-2017 © 2017 Dialog Semiconductor CFR0012 45 of 47...

  • Page 46: Revision History

    UM-B-077 DA14681 Wearable Development Kit Hardware Manual Revision History Revision Date Description 17-Nov-2016 Initial version. 08-Feb-2017 Text revision 06-Apr-2017 Text revision with regards to naming convention User Manual Revision 1.2 06-Apr-2017 © 2017 Dialog Semiconductor CFR0012 46 of 47...
  • Page 47 Dialog Semiconductor excludes all liability in this respect. Customer notes that nothing in this document may be construed as a license for customer to use the Dialog Semiconductor products, software and applications referred to in this document. Such license must be separately sought by customer with Dialog Semiconductor.

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