Wuxi LingDe Microelectronics Co., Ltd. LD903GUB User manual

WUXI LINGDE MICROELECTRONICS CO., LTD
LD903GUB Display Instruction
Manual
V1.0
2017/11/20
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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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 the APP (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.
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.

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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
Power Assisted 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.

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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.
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.

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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 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.
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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SET3-6(password setting ): There is no password when the instrument is out factory. If you want
to change SET3-6 items, you need to enter password or connect APP. Only in that way can it
work well. SET3-6 means the password of 1-9,10-99, 100-999,1000-9999. The corresponding
number will flicker when you press +/- to set. The effective password ranges from 0001 to
9999.
Just forget the password: There is no password when the instrument is out factory. If the user
has set password or forgot the password, please log in the APP and connects the instrument to
unlock automatically.And then come into the menu to set the password as 0000, then you can
cancel the password.

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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
（IOS）Europe
（IOS）Other
（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.
APP Setting Interface
After the first connection is successful, a configuration file must be imported. The method is as
follows: (a mobile phone connection data network)