Wuxi LingDe Microelectronics LD903GUB User manual

WUXI LINGDE MICROELECTRONICS CO., LTD
LD903GUB Display Instruction
Manual
V1.1
2018/5/23
The instrument-LD903GUBis simple and beautiful with the unique design of
scientific ergonomic curve.The LED is not only clearly visible in the sunlight but also
displayed with soft light under the night mode that makes riding safety.

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About our Manual
Please read the manual of LD903GUB carefully before
taking a ride for a better performance.
Size
Instruction to display interface

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Model and parameter
LD903GUB
Five assisted power display
Nine assisted digital display
Standard USB to charge your phone
Bluetooth 4.0 connects theAPP (Fore Rider) in your phone
RS232
Support 24V,36V,48V
Installment guide
1、Fix the instrument on the handlebar and adjust a
appropriate angel.
2、Install the set screw from the bottom of instrument
fixed on the handlebar. It is advised to install the screw
manually.
3、Please insert the connectors of instrument and the
connector of controller on the occasion of power off.

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Definition of button
There are 4 buttons on the instrument,including the
power/mode（M）,up( + )，down( - )and headlight switch（B）.
Routine operation
turn on/ off
ON: press the button of M for a long while on the occasion
of power off, and enter the password if any , then the
instrument starts working , offering the power to controller
and working well with controller after 3 seconds .
OFF: press the button of M for a long while on the occasion
of on , you can turn off without wasting the power.At this
time ,the current is less than 1uA.
Assisted Power Select
Press the button of + or - for a short while , you can change
the output power of motor. The default power ranges
from level 0 to level 5, 1 the lowest, 5 the highest.
When the instrument is on,the default level is 1 just like
the red box in picture below.You can set to 9 via APP in
your phone.
1st gear 9th gear

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PowerAssisted Walk
After holding the button of DOWN for 2 seconds, electric
bicycle will come into the mode of power assist walk,
keeping an even speed at 6 kilometers per hour. The gear
position displays the speed per hour. Release the button to
stop the mode immediately.
Notes:
The function works out at the situation of pushing electric
bicycles. Do not use it when riding.
Turn on/off headlight
Press the key（B）on the side to turn on the
headlight，press the key again to turn off it
and the screen is dimmed.
Display of handover
The instrument will display the current speed and ODO on
the occasion of normal work without breakdown. When
pressing M, you can switch to AVG and TRIP, with the
corresponding indicator light on.

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Capacity display
When voltage is high, 5 battery segments will be alight;
when only 1battery segment is alight , it means low power
and needs to be charged.
Error code display
When something is wrong with the electric control system,
the ERR light will be alight and speed position will show
the error code with the details in APP.
Only when the fault is excluded can it exit the interface. If
the fault happens, the bicycle cannot be ridden.
Parameter setting
In setting menu: You can do settings when pressing + and
-,and entering the password 1234 on the occasion of
power on and normal work of the parking instrument.
(Please note that some types do not have password)
You can set the number password by press + and - for

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a short while. You can set the next number password
by pressing M for a short while. Do the same work till
entering the correct password and coming into the
interface of setting items, just like SE and number 1 in
the picture below.
EXIT Menu:You can exit the setting menu by pressing M
for a long while in any setting menu.Besides, you can
exit the setting menu automatically by pressing M for
a short while and switching all the setting items.
SET1(unit setting): When entering the setting menu, the
default setting is SET1. You can switch the mile and
kilometer by pressing +/-, with the switching of speed
and trip at the same time and corresponding indicator
light on. You can quit the interface by pressing M to
set the next item for a short while or pressing M for a
long while.

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SET2(speed limited): When in SET2, the factory default
limited speed of the instrument is 25km/h. The
effective limited speed ranges from 10 km/h to 41
km/h by pressing +/-. It doesn’t work if over the
range. You can quit the interface by pressing M
for a short while to set the next item or pressing
M for a long while.

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APP Connection
LD808UB can connect with mobile phone through Bluetooth,and can work with Fore Rider APP
of Lishui，and it can be fitted seamlessly with the controllers made by Nanjing Lishui Electronics
Research Institute Co., Ltd.
The user can install the corresponding Fore Rider application according to the style of mobile
phone and the area of users.
The apple (IOS) system is divided into 2 versions, including European one and other regional
ones.
Android version
The European version The other regional version Android version
3 UI interfaces of APP to select
crystal LED interface
苹果（IOS）欧洲版
苹果（IOS）除欧洲外版
安卓（Android）

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Metal pointer interface
The pink interface
LD903GUB goes with bluetooth and the name and password of APP（Fore Rider）
When clicking the corresponding bluetooth equipment in the interface of searching bluetooth in
the APP（Fore Rider）, you will enter the page of password as the picture below:

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After connected successfully, the bluetooth light of LD903GUB will be alight for a long time.
Glittering without connecting app alight for long time after connecting app successfully
The main interface display of APP（Fore Rider）with power off
LED interface
Metal pointer interface
If connected successfully, you will come into the Metal pointer interface, just like the picture
below. If not pressing the power button on the top right corner, all the controller cannot be
clicked.
When clicking power button, please first check whether the instrument is connected and works
well. If yes, the note that please first turn off the instrument will pop up. If the instrument is off,
the power light of APP can be alighted , otherwise, the light cannot be alight.

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When the users touch the speed button(0-9), the current digital gear of LD903GUB will go
accordingly. If holding the button of pushing for 6km for over 2seconds, you will enter the mode
of pushing for 6km with the yellow man glittering and the e-bike will come into the situation of
6km/h.You can exit 6km if loosening the button.
When the users touch the headlight button, the headlight icon will turn red and the headlight is
on. If touched again, the icon will return the colour before opening and the headlight is off.
The trip is showed at the middle and bottom of the speed dial plate. Once touched, the display
will changed from Trip A Trip B to ODO.TripA and TripB can be set as 0 in the setting while ODO
cannot.
APP Setting Interface（after connecting successfully）
Click the tool icon in the metal pointer interface or the LED crystal interface to enter the Settings
page just like the picture below:
In the setting interface, they are in sequence:
Brightness Interface
Clear Single Mileage
bluetooth connection
E-bike setting
E-bike Malfunction Diagnosis
BMS information
program updating
Click on the corresponding cell and enter the corresponding Settings interface.
Brightness Interface

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They are in sequence:
Screen brightness：cell phone brightness adjustment
Style：A choice of display interface style，（choose the metal pointer interface, then the back
home page is the metal pointer interface; If enter the settings interface through the metal
pointer page - > brightness and the interface, the radio button selects the metal pointer
interface by default. The LED crystal interface Settings goes similarly）；
KM5S，JLCD，APT，Bafang5.0
Controller protocol type：KM5S，JLCD，APT，Bafang5.0；
Note: LD808UB only supports the KM5S protocol, and other protocols need to be customized.
Language：four language selections，English，Deutsch，simplified Chinese and traditional
Chinese；
Unit：km and mile（1mile=1.61km）；
Vibration：The choice of whether the button（such as shift up，headlight，power assist walk）
on the interface needs to be vibratory；
The options button of the interface style，controller protocol type，language and unit on the
corresponding settings interface needs to be selected by pressing the corresponding icon or
word.
Clear Single Mileage
When you click the “clear single mileage”, the user will get two options：Reset the Trip - A or
Trip - B;
Trip - A or Trip - B means the distance from place A to place B only（Single mileage in two
different locations and different time periods）；You can set the number to zero when you set off
from place A, and the number shown until you arrive to place B is the distance between them，
both of them can set the reset timing and timing conditions respectively；

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E-bike Settings Interface
Click the“e-bike settings”to enter the corresponding interface as below：
Speed Limit Setting
Click the “speed limit”to enter the corresponding interface as below：
you can go back to the last category
The wheel diameter can be selected through the drop-down box ，you can choose
16inch,18inch,20inch,22inch,24inch,26inch,700cc,28inch，the default wheel diameter is 26inch.
The current maximum speed limit is 25Km/h and the default speed limit is 25 Km/h，If you have
set the unit ：Mile, here shows the mile, but the data can be converted to km，You can slide the
speed box to select a reasonable speed limit.
The default speed magnet number is 1，The user can select it according to the actual situation by

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the drop-down box.
Current and Voltage Settings
Click the “current and voltage”to enter the corresponding interface as below：
The default of the battery capacity is 12Ah, users can select the battery capacity according to the
actual demand, slide left or right to reduce or increase the capacity of the battery;
The default of the full voltage is 36V; the user can choose the battery capacity according to the
actual demand, slide left or right to reduce or increase the full voltage v( *LD808UB does not
support);
The default of the low voltage is 31V; the user can choose the battery capacity according to the
actual demand, slide left or right to reduce or increase the low voltage, but low voltage must be
less than the full voltage;
Limited current, means the maximum discharge current of the battery, its default is 12A, the
user can select the maximum discharge current of the battery according to the actual demand,
slide left or right to reduce or increase the current limit;
The default of acceleration is 100%, the user can choose the acceleration value according to
actual demand, slide left or right to reduce or increase the acceleration value;(Bafang protocol
does not support)
The total number of assisted power setting（Bafang protocol does not support the power ratio）

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The total number of assisted power is 5 by default，the user can choose it according to actual
demand, the below shows the corresponding assisted power percentage. Slide up or down to
check all the percentage values of the assisted power. The latter percentage must be greater
than or equal to the previous one. The total number should be adjusted to the default value of
each assisted power.
1st 100%
Second 50 % 100%
Third 40% 70% 100%
4th 40% 60% 80% 100%
5th 40% 55% 70% 85% 100%
6th 40% 52% 64% 76% 88% 100%
7th 40% 50% 60% 70% 80% 90% 100%
8th 40% 48% 57% 65% 74% 82% 91% 100%
9th 40% 48% 55 % 63% 70% 78% 85% 93% 100%
PAS setting interface（Bafang protocol does not support）
PAS，magnet per circle means pluses per circle，the default is 12；
Forward pulse duty cycle，choose >50%, the wheel will get the assisted power when it inverts；
choose <50%, the wheel will get the assisted power when it forwards；Slide the Forward pulse
duty cycle button to choose.
The default of start after magnet number is 2，the user can set it according to actual demand.
Throttle setting interface（Bafang protocol does not support）

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Open the [6 km/h speed limit for the throttle] function, then in the process of driving, no matter
what level by the throttle do you select, the speed will be limited less than 6 km/h.
Open the [throttle level select] function，the corresponding speed and power will change
accordingly when adjusting the level in metal pointer or crystal LED page. On the contrary, it
won't change.
E-bike Malfunction Diagnosis
By testing the brake, controller, and other components, to ensure that the problem can be
detected in advance, and not affect the normal use of e-bike
Refound and resetting of password
Refound and resetting of password: if users just forget their
password, they can refind or reset their password via
offered APP.
Appealing of password: if users lost and cannot find their
password via APP, they can appeal to the manufacturer to
refind their password based on their invoice. Please contact
the manufacturer if any.

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Quality Warranty
一、warranty coverage：
1、When the malfunction is caused by the quality of the
product itself under regular use condition，our company will
be responsible for it under guarantee.
2、24 months from the delivery time of the display out of the
factory.
二、The following conditions are not covered by the
warranty.
1、The shell is open.
2、The connectors are broken.
3、The shell is scratched or damaged after out of factory.
4、The lead wires from the display are scratched or broken.
5、Damages are caused by irresistible (e.g. fire, earthquake,
etc) or natural disasters (such as lightning, etc.);
6、The product exceeds the warranty period.

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Wiring Diagram
The display is matched with 5-waterproof wire and the wire
definitions are as below.
number
colour
function
1
red(VCC)
Power B+
2
black(GND)
Power B-
3
yellow(TX)
Gorge line: sending message
4
green(RX)
Gorge line: receiving message
5
blue(K)
Electric door look offer weak power
to other equipment
Note：Users cannot see the color of the internal wiring
because of the water proof connector.