Wuxi LingDe Microelectronics LD803U User manual

Wuxi LingDe Microelectronics Co., Ltd.
LD803U Display Instruction Manual
V1.0
2017/7/22
LD803U display is simple and beautiful as it adopts the scientific ergonomic curve design.
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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Preface
Dear users, to ensure better performance of your e-bike, please read through the
LD803U product introduction carefully before using it.
Size (Unit: mm)
Description

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Model and Parameters
LD803U
Five assisted power display
Nine assisted digital display
USB mobile charging
Support 232 or 485 bus mode
Support voltage 24V、36V、48V
Installation Instruction
1、Fix the display onto the handlebar and adjust to an appropriate visual angle.
2、Fit the matching screws from the bottom.(manual operation is recommended)
3、In the case the electric bicycle is powered off, match display connectors with
controller connectors.
Button
There are four buttons on the display，including the power/mode（M）,up( + )，down( - )and
headlight switch（B）.

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Normal Operation
On/Off
Power on：In the shutdown state, long press the（M）button, display begins to work for the
controller power supply，after 3 seconds，the display will communicate with the controller
normally.
Power off：In the power on state, long press the（M）button to cut off the e-bike power
supply. In the power off state, the display no longer uses the battery power supply, and
the leakage current is smaller than 1uA.
Assisted Power Select
Short press the key（+）or key（-）to change the motor output power, the power ranges
from level 0 to level 5, level 1 is the minimum power, level 5 is the maximum power. The
default level is level 1.
Level 1 level 9
Power Assist Walk
Hold the key（-）2 seconds and enter into the mode of power assist walk. The e-bike will
go on at a uniform speed of 6 KM/H，release the key（-）to stop the mode immediately.
This function can only be used when the user is pushing the e-bike. Please don’t
use this function during riding.

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Turn on and Turn off the 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.
Capacity Display
When the battery capacity is high，the five battery segments are all light.When the
battery is low voltage，the battery display frame will flash at the frequency of 1HZ. This
indicates that the battery is severely low voltage and needs to be recharged
immediately.
Malfunction Code Display
If there is something wrong with the electronic control system，the display will show the
error code automatically. Only the malfunction is excluded, the display will be working
normal again. In the meantime，you can’t ride your e-bike continuously. The following are
some definition of malfunction codes.
Malfunction Code
Definition
Solution
9
Communication abnormality
Check the display connector
1
Current abnormality
Check the three-phase power line
2
Throttle abnormality
Check the throttle
3
Motor open-phase
Check the three-phase power line
4
Motor hall signal abnormality
Check the motor hall connector
5
Brake abnormality
Check the brake

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Quality Warranty
1，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.
2，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 leaving the 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
Color
Function
1
red(VCC)
Power B+
2
black(GND)
Power B-
3
yellow(TX、B)
232：TX、 485：B
4
green(RX、A)
232：RX 、485：A
5
blue(K)
Lock
Note：Users cannot see the color of the internal wiring because of the water proof
connector.