GlobalTop-DR-Application-Notes

 Ver. A02 Technical Document GlobalTop Technology Inc. DR System Application Notes (Gnd‐r5 + Gmm‐u2p)
Revision: A02 Reference layout, design tips, guides, and cautions for GlobalTop GPS modules. This document is the exclusive property of GlobalTop Tech Inc. and should not be distributed, reproduced, into any other format without prior permission of GlobalTop Tech Inc. Specifications subject to change without prior notice. Copyright © 2013 GlobalTop Technology Inc. All Rights Reserved. No.16 Nan‐ke 9th Rd, Science‐Based Industrial Park, Tainan, 741, Taiwan, R.O.C. Tel: +886‐6‐5051268 / Fax: +886‐6‐5053381 / Email: sales@gtop‐tech.com / Web: www.gtop‐tech.com GlobalTop Technology Gnd‐r5 DR Module Application Notes 2 Ver. A02
Version History
Title:
Subtitle:
Doc Type:
GlobalTop DR System Application Notes
(Gnd-r5 + Gmm-u2p)
DR Module
Technical Document
Revision
A00
A01
Date
2013-07-08
2013-07-19
Editor
Antonio
Antonio
A02
2013-07-26
Antonio
Description
First Release
Gmm-u2p pin outs added @General
HW design Rules, photo added, some
wordings
Add debug pin function description,
Troubleshooting
This document is the exclusive property of GlobalTop Tech Inc. and should not be distributed, reproduced, into any other format without prior permission of GlobalTop Tech Inc. Specifications subject to change without prior notice. Copyright © 2013 GlobalTop Technology Inc. All Rights Reserved. GlobalTop Technology Gnd‐r5 DR Module Application Notes 3 Ver. A02
Table of Contents
Table of Contents .......................................................................................................................... 3 Attention ...................................................................................................................................... 4 Technical Support ......................................................................................................................... 5 1. Introduction .............................................................................................................................. 6 2. General Rules for Hardware Design ........................................................................................... 7 2.1 Circuit Design ......................................................................................................... 8 2.1.1 Power supply VCC .................................................................................................................. 8 2.1.2 UART0 (RX0/TX0) –Serial Interface ........................................................................................ 8 2.1.3 DR Baud Rate setting ............................................................................................................. 9 2.1.4 Odometer/Direction‐ Input interface .................................................................................... 9 2.1.5 GND‐Ground ........................................................................................................................ 10 2.1.6 1PPS...................................................................................................................................... 10 2.1.7 Calibration ............................................................................................................................ 11 2.2 Layout Guideline ............................................................................................. 13 2.2.1 Layout underneath the DR module ..................................................................................... 13 2.2.2 Trace ..................................................................................................................................... 13 2.2.3 Ground Segmentation .......................................................................................................... 14 2.2.4 Place of the DR Module ....................................................................................................... 14 3. Troubleshooting ...................................................................................................................... 15 4. Contact ................................................................................................................................... 17 This document is the exclusive property of GlobalTop Tech Inc. and should not be distributed, reproduced, into any other format without prior permission of GlobalTop Tech Inc. Specifications subject to change without prior notice. Copyright © 2013 GlobalTop Technology Inc. All Rights Reserved. GlobalTop Technology Gnd‐r5 DR Module Application Notes Attention
Please read carefully before you start: ¾
¾
This application note provides the necessary guideline to successfully design a system using DR modules. For detailed module specification, please refer to the corresponding datasheet of DR module. DR Module is an electrostatic sensitive device, please don’t touch DR module directly, please follow ESD safety rule when handling. ¾
Basically, the Gyro sensor need a specific calibration procedure to minimize the internal bias to archive accurate data output. The DR module is equipped with a built–in automatic calibration mechanism and therefore the user need not to design for DR system calibration. ¾
Gnd‐r5 is designed to be used with Gtop GPS module Gmm‐u2p and therefore the reference design suggested in this document is built around Gmm‐u2p. ¾
For Gmm‐u2p reference circuit, please refer to Gmm‐u2p application notes and datasheet. This document is the exclusive property of GlobalTop Tech Inc. and should not be distributed, reproduced, into any other format without prior permission of GlobalTop Tech Inc. Specifications subject to change without prior notice. Copyright © 2013 GlobalTop Technology Inc. All Rights Reserved. 4 Ver. A02
GlobalTop Technology Gnd‐r5 DR Module Application Notes Technical Support
If you have any technical problems or any required information is not found elsewhere in our documents, please feel free to contact us. When write to use please follow the form bellow to help us to serve you better. : 1. Your company name and website 2. Description on your application and system. Please attach illustration figures where applicable. 3. Detail descriptions of problem encountered and the conditions by which the problem occurred ‐if known along with pictures or videos files. ─
Test setup descriptions ─
The problem or issue addressable in the figures Technical contact information: support@gtop‐tech.com This document is the exclusive property of GlobalTop Tech Inc. and should not be distributed, reproduced, into any other format without prior permission of GlobalTop Tech Inc. Specifications subject to change without prior notice. Copyright © 2013 GlobalTop Technology Inc. All Rights Reserved. 5 Ver. A02
GlobalTop Technology Gnd‐r5 DR Module Application Notes 1. Introduction
Gtop’s Dead Reckoning System consists of a modular based Gnd‐r5 which works in conjunction with Gmm‐u2p GPS module. The system is designed to provide dead reckoning navigation solution to customer’s existing GPS system to enhance automobile tracking application. Gnd‐r5 outputs a synthesized NMEA 0183 sentence resulted from the blending of Gyro sensor, wheel ticking and the raw NMEA data of Gmm‐u2p GPS module. The application tries to have customer designing the DR Module into their own system easily and provides related design check points. We also provide DR EVKs for customer’s evaluation. For detail please contact Gtop’s sales representative. Gnd‐r5 module Gmm‐u2p GPS module This document is the exclusive property of GlobalTop Tech Inc. and should not be distributed, reproduced, into any other format without prior permission of GlobalTop Tech Inc. Specifications subject to change without prior notice. Copyright © 2013 GlobalTop Technology Inc. All Rights Reserved. 6 Ver. A02
GlobalTop Technology Gnd‐r5 DR Module Application Notes 2. General Rules for Hardware Design
In order to obtain good performance, there are some rules which require customer’s attentions on using DR module. Vehicular DR application circuit: This document is the exclusive property of GlobalTop Tech Inc. and should not be distributed, reproduced, into any other format without prior permission of GlobalTop Tech Inc. Specifications subject to change without prior notice. Copyright © 2013 GlobalTop Technology Inc. All Rights Reserved. 7 Ver. A02
GlobalTop Technology Gnd‐r5 DR Module Application Notes 8 Ver. A02
2.1 Circuit Design
2.1.1 Power supply VCC It is necessary to provide a clean and stable power supply for the module to obtain good performance. Unstable power source will have a significant negative impact on the performance. To achieve this, the Vcc ripple must be minimized under 50mVpp. In addition, there are also some important suggestions for main power circuit design: (1) Add ferrite bead, power choke or low pass filter for power noise reduction. (2) Linear regulator is better than switch DC/DC power supplier in ripple consideration. (3) Use enough decoupling capacitors beside VCC for stable voltage. Power design for DR module 2.1.2 UART0 (RX0/TX0) –Serial Interface (1) UART0 (RX0/TX0) is the default interface (TTL level) with Baud rate ranging from 9600 bps to 115200 bps. The default is 9600bps. (2) RX0 is used to receive NMEA from the front‐end GPS module. TX0 is used as main output DR NMEA. (3) Placing damping resistor on the RX0 and TX0 of the DR module could limit the interference from host MCU or high speed digital logics. Fine tuning the damping resistor is required to suppress interference effect. (4) Please don’t connect diode(s) to RX0/TX0. It will decrease signal driving capability which might adversely affect RX0/TX0 signal level (ex. no data output). This document is the exclusive property of GlobalTop Tech Inc. and should not be distributed, reproduced, into any other format without prior permission of GlobalTop Tech Inc. Specifications subject to change without prior notice. Copyright © 2013 GlobalTop Technology Inc. All Rights Reserved. GlobalTop Technology Gnd‐r5 DR Module Application Notes 9 Ver. A02
2.1.3 DR Baud Rate setting (1) Please make sure the Baud rate setting is the same as input Baud rate of Gmm‐u2p GPS module. (2) Gnd‐r5 Baud rate is programmable via pin configuration. For setting method, please refer to the Gnd‐r5 datasheet. Baud Rate Set for DR Module 2.1.4 Odometer/Direction‐ Input interface (1) Please make sure the odometer signal or direction signal cable is ready for testing. (2) The odometer signal or direction signal must be fed to DR Module via an optoisolator circuitry for interference and electrical isolation. Electrical Isolation Fig. Reference circuit
This document is the exclusive property of GlobalTop Tech Inc. and should not be distributed, reproduced, into any other format without prior permission of GlobalTop Tech Inc. Specifications subject to change without prior notice. Copyright © 2013 GlobalTop Technology Inc. All Rights Reserved. GlobalTop Technology Gnd‐r5 DR Module Application Notes 10 Ver. A02
2.1.5 GND‐Ground Make sure all GND pins of module are connected to a good ground plane. Please refer to “2.2.3 Ground Segmentation”. 2.1.6 1PPS Gnd‐r5 requires 1PPS input from the front‐end Gmm‐u2p GPS Module for timing synchronization. 1PPS signal is an output pulse signal from the GPS module which has the signal characteristic shown below: 1PPS signal and its pulse width with 100ms duration Low Voltage level: 0~0.4V High Voltage level: 2.8~3.1V Duration: 100ms Period: 1s For your reference: Whatever Fixed or not, the Gmm‐u2p GPS module must always output the 1pps as soon as the module is powered on. 1PPS of the system This document is the exclusive property of GlobalTop Tech Inc. and should not be distributed, reproduced, into any other format without prior permission of GlobalTop Tech Inc. Specifications subject to change without prior notice. Copyright © 2013 GlobalTop Technology Inc. All Rights Reserved. GlobalTop Technology Gnd‐r5 DR Module Application Notes 11 Ver. A02
2.1.7 Calibration The DR Module could automatically processes a calibration procedure for inertial components (Gyro sensor) along with the normal usage. It will calibrate and getting higher calibration completion rate gradually accompanied with the user drive on the road. When the calibration is 74% or above , the DR Module is said to have achieve its minimum or enough calibration for the DR application and the system would operate under EKF mode. The percentage can be monitored on the provided Dr View test software for reference. The following is the calibration procedure. Ensure that the speed line is attached to your system before proceeding. 1.
Drive your car under an open sky and stay still for a position fix. As in Dr Viewer software, DR status should appear 3D Fix. After such 3D Fix wait for another 90 seconds at least to ensure that the FIX is stable. TIP. a. Observe to see if the 3D Fix pin out (LED Indicator output) on Gmm‐u2p GPS module stays on or constant low‐level output or non‐blinking if LED is connected. 2.
Drive the car and keep the speed higher than 50km/hr along a rectangle contour with side length over 400m. Run 3 laps around the rectangle block as described in the figure bellow. (3) Finally, when the calibration has reached to 95% the calibration is said to be saturated. This document is the exclusive property of GlobalTop Tech Inc. and should not be distributed, reproduced, into any other format without prior permission of GlobalTop Tech Inc. Specifications subject to change without prior notice. Copyright © 2013 GlobalTop Technology Inc. All Rights Reserved. GlobalTop Technology Gnd‐r5 DR Module Application Notes 12 Ver. A02
Dr View test software This document is the exclusive property of GlobalTop Tech Inc. and should not be distributed, reproduced, into any other format without prior permission of GlobalTop Tech Inc. Specifications subject to change without prior notice. Copyright © 2013 GlobalTop Technology Inc. All Rights Reserved. GlobalTop Technology Gnd‐r5 DR Module Application Notes 13 Ver. A02
2.2 Layout Guideline Please follow the layout criteria to design a system using DR module. 2.2.1 Layout underneath the DR module In order to minimize the influence of noise to DR module, please do not place any trace underneath the DR module. In other words, give DR module a complete GND plane instead. DR EV‐Kit PCB Example 2.2.2 Trace (1). The USB differential signals should be trace close and equal‐length for minimum radiation and noise immunity. (2). Any right angle turn in trace routing should be accomplished with two 135 degree turn or an arc turn This document is the exclusive property of GlobalTop Tech Inc. and should not be distributed, reproduced, into any other format without prior permission of GlobalTop Tech Inc. Specifications subject to change without prior notice. Copyright © 2013 GlobalTop Technology Inc. All Rights Reserved. GlobalTop Technology Gnd‐r5 DR Module Application Notes 14 Ver. A02
It is better to have independent trace of power source for any device 2.2.3 Ground Segmentation The separation of ground between DR module and the rest of the system is recommended to avoid interference. Some typical rules such as segmentation of ground between digital and analogue system, high current and low current system, and different radiation systems (such as DR and GPRS). One way to segment the ground is to place digital and noise component at one corner (side) of the board, while placing analog and quiet components at the opposite corner of the board. Make sure there is no crossing of microstrips or current between the two component sets and grounds of each sets are contacted at one point only. Another way to do this is to place the two different sets at different layers of the board, while the ground of each layer is contacted at one point only (preferable at the border of the board). 2.2.4 Place of the DR Module A consideration regarding to the housing and the environment where it was placed should be taken carefully. As shown in the figure, the module should be placed as Z axis direction. This document is the exclusive property of GlobalTop Tech Inc. and should not be distributed, reproduced, into any other format without prior permission of GlobalTop Tech Inc. Specifications subject to change without prior notice. Copyright © 2013 GlobalTop Technology Inc. All Rights Reserved. GlobalTop Technology Gnd‐r5 DR Module Application Notes 15 Ver. A02
3. Troubleshooting
How to check for the working status of DR module? The first thing to check for is the NMEA sentence output through TX0 (Pin_25) by using various application tools. For example: you may use Windows default tool ‐ WinXP Hyperterminal, or you may use other GPS application programs. If there is no NMEA output, this indicates the module is currently not working. Please double check your schematic design. For your reference, below are some of the possible items to check: Item 1: VCC The voltage should be kept between 3.2V to3.6V. (Typical: 3.3V). Please double‐check. Item 2: 1PPS If all the measurements are within the specifications, please also measure 1PPS signal from GPS. The pin should output 100ms width pulse with one‐second signal at all times. Please double‐check. This document is the exclusive property of GlobalTop Tech Inc. and should not be distributed, reproduced, into any other format without prior permission of GlobalTop Tech Inc. Specifications subject to change without prior notice. Copyright © 2013 GlobalTop Technology Inc. All Rights Reserved. GlobalTop Technology Gnd‐r5 DR Module Application Notes 16 Ver. A02
Item 3: TX0 The UART transmitter of the DR module outputs the DR NMEA data for DR application. Item 4: Debug When DR module is work properly, the debug pin (Pin_18) should output 12ms~100ms low‐level duration with one‐second interval. If not, please check all the connection status. Check for 1PPS output from GPS module, correct Baud Rate setting and NMEA sentence output from GPS module. This document is the exclusive property of GlobalTop Tech Inc. and should not be distributed, reproduced, into any other format without prior permission of GlobalTop Tech Inc. Specifications subject to change without prior notice. Copyright © 2013 GlobalTop Technology Inc. All Rights Reserved. GlobalTop Technology Gnd‐r5 DR Module Application Notes 4. Contact
For help or further information, please contact us via the following methods: GlobalTop Technology Inc. Tainan Science‐Based Industry Park Headquarter: Address: No.16 Nan‐ke 9th Road Science‐based Industrial Park, Tainan 74147, Taiwan Tel: +886‐6‐505‐1268 Fax: +886‐6‐505‐3381 Sales Email: sales@gtop‐tech.com Technical Support Email: support@gtop‐tech.com This document is the exclusive property of GlobalTop Tech Inc. and should not be distributed, reproduced, into any other format without prior permission of GlobalTop Tech Inc. Specifications subject to change without prior notice. Copyright © 2013 GlobalTop Technology Inc. All Rights Reserved. 17 Ver. A02