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.

Wuxi LingDe Microelectronics Co., Ltd.
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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

Wuxi LingDe Microelectronics Co., Ltd.
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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.

Wuxi LingDe Microelectronics Co., Ltd.
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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.