AN_216 Using the FT230X to design a GPS Dongle

Application Note
AN_216
Using the FT230X to design a GPS
Dongle
Version 1.1
Issue Date: 2013-09-09
This application note illustrates how to develop a GPS to USB design using the
FTDI FT230X chip.
Use of FTDI devices in life support and/or safety applications is entirely at the user’s risk, and the
user agrees to defend, indemnify and hold FTDI harmless from any and all damages, claims, suits
or expense resulting from such use.
Future Technology Devices International Limited (FTDI)
Unit 1, 2 Seaward Place, Glasgow G41 1HH, United Kingdom
Tel.: +44 (0) 141 429 2777 Fax: + 44 (0) 141 429 2758
Web Site: http://ftdichip.com
Copyright © 2012 Future Technology Devices International Limited
Application Note
AN_216 Using the FT230X to design a GPS Dongle
Version 1.1
Document Reference No.: FT_000698
Clearance No.: FTDI# 301
Table of Contents
1
Introduction .................................................................................................................................... 2
1.1
Overview ................................................................................................................................. 2
1.2
Background ............................................................................................................................. 2
2
Example Circuit ............................................................................................................................... 3
3
PCB Data.......................................................................................................................................... 6
4
Using FT230XQ GPS Dongle as a location sensor under Windows 7 .............................................. 7
5
Contact Information........................................................................................................................ 9
Appendix A – References ...................................................................................................................... 10
Document References....................................................................................................................... 10
Acronyms and Abbreviations ............................................................................................................ 10
Appendix B – List of Figures .................................................................................................................. 11
List of Figures .................................................................................................................................... 11
Appendix C – Revision History .............................................................................................................. 12
1
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_216 Using the FT230X to design a GPS Dongle
Version 1.1
Document Reference No.: FT_000698
Clearance No.: FTDI# 301
1 Introduction
The FT230X is a USB to serial UART interface with optimised pin count for smaller PCB designs,
offering single-chip USB to asynchronous serial data transfer interface. The entire USB protocol is
handled on the chip. No USB specific firmware programming is required.
Small PCB footprint makes it ideal for space constrained applications such as the design of a GPS
dongle – as described in this application note.
1.1 Overview
This application note gives detail of how to implement a GPS dongle design, which can be used to
enable location services under Windows Operating System, using the FT230X USB to basic UART
Bridge IC.
The application can be used as a reference design for the FT230X and details of the schematic and
layout are given for reference.
1.2 Background
Computers today are more mobile than ever. From small laptops to Tablet PCs, many computers
can go wherever the user wants to go. Programs that take advantage of the computer's mobility
can add significant value to people's lives. For example, a program that can find nearby
restaurants and provide driving directions would seem to be a natural fit for a portable computer.
Starting with Windows 7, the Windows Sensor and Location platform enables the computer and
applications to adapt to their current environment. With location sensors – such as GPS devices,
applications and gadgets can know exactly where they are, enabling them to provide relevant
content and functionality.
2
Copyright © 2013 Future Technology Devices International Limited
USB Plug
VBUS
DD+
GND
CN1
1
2
3
4
GND
C3
10nF
GND
C5
0.1uF
2x47pF
C1 C2
FB1
600R/0.5A
GND
C4
4.7uF
R1
R2
27R
27R
9
7
6
8
GND
C6
0.1uF
3V3OUT
RESET#
USBDM
USBDP
3V3OUT
U1
10
VCC
1
VCCIO
GND
GND
GND
GND
3
13
17
FT230XQ
CBUS0
CBUS1
CBUS2
CBUS3
TXD
RXD
RTS#
CTS#
12
11
5
14
15
2
16
4
R3
2k
R4
100k
C11
1uF
R5
1M
7
6
1
2
3
C8
0.1uF
3V3OUT
CX/RX
CX
Q
5
GND
CX/RX
CX
A
B
CLR
U3
3V3OUT
GND
Q
5
1PPS
R10
10k
N.F.
GND
74LVC1G123
0.1uF
GND
7
6
1
2
3
3V3OUT
R11 R12
10k 10k
0.1uF
C12
0.1uF
R6
1M
GND
C10
4.7uF
C14
GND
C9
0.1uF
C13
GND
GND
74LVC1G123
3V3OUT
GND
A
B
CLR
U2
C7
0.1uF
U4
AIC1747-18GU3
3 Vin Vout 2
1
Q1
IRLML6402
8
VCC
GND
4
8
VCC
GND
4
VBUS
1PPS
GND
1
2
3
4
5
6
GP-2106
VCC
GND
1PPS
ON/OFF
RX
TX
M1
2k
R7
Q2
IRLML2502
GND
R8
100k
LED1
Blue
R9
560R
VBUS
FPC/FFC cable 6-pin 0.5mm pitch
CB1
503480-0600
1
2
3
4
5
6
CN2
AN_216 Using the FT230X to design a GPS Dongle
Application Note
Version 1.1
Document Reference No.: FT_000698
Clearance No.: FTDI# 301
2 Example Circuit
The schematic diagram below gives details of how the FT230XQ chip can be connected to a GPS
receiver to create a USB based GPS sensor. In this case a GPS module – GP-2106 has been used.
Figure 2.1 FT230XQ GPS Dongle circuit diagram
3
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_216 Using the FT230X to design a GPS Dongle
Version 1.1
Document Reference No.: FT_000698
Clearance No.: FTDI# 301
The FT230XQ (U1) provides the UART to USB conversion while GPS Module – GP-2106 (M1)
provides location data in NMEA0183 v.3.01 format.
For more information about GP-2106 GPS receiver please visit the product web site:
http://www.adh-tech.com.tw/?gp-2106(sirf-star-iv),71
More information on the FT230XS may be obtained from the FTDI web page:
http://www.ftdichip.com/Products/ICs/FT230X.html
The implementation is straight-forward with TXD output from the FT230XQ connected to RXD
input of the GP-2106 GPS receiver and RXD input of the FT230XQ connected to TXD output from
the GP-2106. These connections form a data link between the GPS receiver and USB port. RTS#
and CTS# pins of the FT230XQ are connected together to disable hardware flow control.
To properly start-up the GPS receiver, power must be applied and ‘On’ pulse must be generated at
pin-4 of the receiver. To satisfy this condition two monostable multivibrators (74LVC1G123) have
been employed. First multivibrator U2 generates a delay during which the FT230XQ is enumerated
by the USB host controller and power is applied to the GPS receiver. The second multivibrator
generates an ‘On’ pulse (high level) which starts-up the chipset inside the GPS receiver module.
Figure below illustrates the behaviour of the start-up circuit.
Figure 2.2 Start-up circuit scope waveforms
CH.1 (Yellow trace) was taken from the U1-pin-12 (CBUS0). CBUS0 is configured as an output of
PWREN# signal.
CH.2 (Blue trace) probe was connected to the ‘Q’ output of U2.
CH.3 (Purple trace) probe was connected to the ‘Q’ output of U3.
4
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_216 Using the FT230X to design a GPS Dongle
Version 1.1
Document Reference No.: FT_000698
Clearance No.: FTDI# 301
The PWREN# pin toggles during the USB enumeration process and then it stays low as long as U1
is enumerated and the host computer is not in ‘sleep’ mode (i.e. it is not hibernated). A logic low
level at this pin also enables the Q1 MOSFET transistor to conduct, feeding ‘VBUS’ (+5V) to the
input of U4 voltage regulator. U4 reduces this voltage to 1.8V required by the GPS receiver.
As soon as PWREN# pin goes low for the first time, U2 triggers, driving its output high.
Approximately 1.6 seconds later U2 output will go low triggering U3 which will generate ‘On’ pulse
at the ‘ON/OFF’ input of the GPS receiver.
GPS dongle PCB has been equipped with the blue status LED (LED1). This LED will blink once a
second when GPS fix is available (valid position has been acquired). LED1 is controlled by ‘1PPS’
output from GPS receiver through Q2 MOSFET transistor.
5
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_216 Using the FT230X to design a GPS Dongle
Version 1.1
Document Reference No.: FT_000698
Clearance No.: FTDI# 301
3 PCB Data
FT230XQ GPS Dongle PCB files are available in Gerber format and Altium Designer project files and
can be downloaded here:
http://www.ftdichip.com/support/documents/schematics/HW_248_rev1_1.zip
6
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_216 Using the FT230X to design a GPS Dongle
Version 1.1
Document Reference No.: FT_000698
Clearance No.: FTDI# 301
4 Using FT230XQ GPS Dongle as a location sensor under
Windows 7
To use FT230XQ GPS Dongle as a location sensor, a special driver must be installed.
There are many location sensor drivers freely available on the web. One of them can be
downloaded from following location: http://www.turboirc.com/gps7/
7
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_216 Using the FT230X to design a GPS Dongle
Version 1.1
Document Reference No.: FT_000698
Clearance No.: FTDI# 301
5 Ordering Information
Due to the large volume of interest expressed in this solution by FTDI customers, FTDI are
delighted to offer a finished product, ready to use in a tough, contoured, hardened plastic
enclosure.
The module has a type A USB connector with dust cap for connecting to the USB host and will be
powered from the USB host.
Figure 5.1 FT-X-GPS Dongle
Module Code
Utilised IC Code
Description
FT-X-GPS
FT230XQ
USB GPS Dongle
Table 5-1 – Ordering Information
Drivers for the FT230X are available at:
http://www.ftdichip.com/Drivers/VCP.htm
8
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_216 Using the FT230X to design a GPS Dongle
Version 1.1
Document Reference No.: FT_000698
Clearance No.: FTDI# 301
6 Contact Information
Head Office – Glasgow, UK
Branch Office – Tigard, Oregon, USA
Future Technology Devices International Limited
Unit 1, 2 Seaward Place, Centurion Business Park
Glasgow G41 1HH
United Kingdom
Tel: +44 (0) 141 429 2777
Fax: +44 (0) 141 429 2758
Future Technology Devices International Limited
(USA)
7130 SW Fir Loop
Tigard, OR 97223
USA
Tel: +1 (503) 547 0988
Fax: +1 (503) 547 0987
E-mail (Sales)
E-mail (Support)
E-mail (General Enquiries)
[email protected]
[email protected]
[email protected]
E-Mail (Sales)
E-Mail (Support)
E-Mail (General Enquiries)
[email protected]
[email protected]
us.[email protected]
Branch Office – Taipei, Taiwan
Branch Office – Shanghai, China
Future Technology Devices International Limited
(Taiwan)
2F, No. 516, Sec. 1, NeiHu Road
Taipei 114
Taiwan , R.O.C.
Tel: +886 (0) 2 8791 3570
Fax: +886 (0) 2 8791 3576
Future Technology Devices International Limited
(China)
Room 1103, No. 666 West Huaihai Road,
Shanghai, 200052
E-mail (Sales)
E-mail (Support)
E-mail (General Enquiries)
[email protected]
[email protected]
m
[email protected]
China
Tel: +86 21 62351596
Fax: +86 21 62351595
E-mail (Sales)
E-mail (Support)
E-mail (General Enquiries)
[email protected]
[email protected]
[email protected]
Web Site
http://ftdichip.com
System and equipment manufacturers and designers are responsible to ensure that their systems, and any Future Technology
Devices International Ltd (FTDI) devices incorporated in their systems, meet all applicable safety, regulatory and system-level
performance requirements. All application-related information in this document (including application descriptions, suggested
FTDI devices and other materials) is provided for reference only. While FTDI has taken care to assure it is accurate, this
information is subject to customer confirmation, and FTDI disclaims all liability for system designs and for any applications
assistance provided by FTDI. Use of FTDI devices in life support and/or safety applications is entirely at the user’s risk, and the
user agrees to defend, indemnify and hold harmless FTDI from any and all damages, claims, suits or expense resulting from
such use. This document is subject to change without notice. No freedom to use patents or other intellectual property rights is
implied by the publication of this document. Neither the whole nor any part of the information contained in, or the product
described in this document, may be adapted or reproduced in any material or electronic form without the prior written consent
of the copyright holder. Future Technology Devices International Ltd, Unit 1, 2 Seaward Place, Centurion Business Park,
Glasgow G41 1HH, United Kingdom. Scotland Registered Company Number: SC136640
9
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_216 Using the FT230X to design a GPS Dongle
Version 1.1
Document Reference No.: FT_000698
Clearance No.: FTDI# 301
Appendix A – References
Document References
FT230XQ webpage:
http://www.ftdichip.com/Support/Documents/DataSheets/ICs/DS_FT230X.pdf
GP-2106 webpage:
http://www.adh-tech.com.tw/?gp-2106(sirf-star-iv),71
Information on GPS system:
http://en.wikipedia.org/wiki/Global_Positioning_System
Information on Windows Location API:
Acronyms and Abbreviations
Terms
Description
GPS
Global Positioning System
LED
Light Emitting Diode
MOSFET
Metal–Oxide–Semiconductor Field-Effect Transistor
RXD
Receive Data (The receive data line of RS232)
TXD
Transmit Data (The transmit data line of RS232)
UART
USB
USB-IF
Universal Asynchronous Receiver/Transmitter
Universal Serial Bus
USB Implementers Forum
10
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_216 Using the FT230X to design a GPS Dongle
Version 1.1
Document Reference No.: FT_000698
Clearance No.: FTDI# 301
Appendix B – List of Figures
List of Figures
Figure 2.1 FT230XQ GPS Dongle circuit diagram ..................................................................... 3
Figure 2.2 Start-up circuit scope waveforms ........................................................................... 4
Figure 5.1 FT-X-GPS Dongle ................................................................................................. 8
List of tables
Table 5-1 – Ordering Information .......................................................................................... 8
11
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_216 Using the FT230X to design a GPS Dongle
Version 1.1
Document Reference No.: FT_000698
Clearance No.: FTDI# 301
Appendix C – Revision History
Document Title:
AN_216 Using the FT230X to design a GPS Dongle
Document Reference No.:
FT_000698
Clearance No.:
FTDI# 301
Product Page:
http://www.ftdichip.com/Support.htm/FTReferenceDesigns.htm
Document Feedback:
Send Feedback
Revision
1.0
Changes
Date
Initial Release
2012-07-09
Included details of dongle for retail.
1.1
Updated US contact details
2013-08-08
Added image in section 5
12
Copyright © 2013 Future Technology Devices International Limited