Garmin V3HP User Manual

LIDAR-Lite v3HP Operation Manual

and Technical Specications

Laser Safety

This device requires no regular maintenance. In the event that the device becomes damaged or is inoperable, repair or service must be handled by authorized, factory-trained technicians only. Attempting to repair or service the unit on your own can result in direct exposure to laser radiation and the risk of permanent eye damage. For repair or service, contact your dealer or

Garmin

for more information. This device has a protective housing which, when in place, prevents human access to laser radiation in excess of the accessible emission limit (AEL) for Class 1 laser products. This device should

not be modied or operated without its housing or optics. Operating this device without a housing and optics, or operating this device with a modied housing

or optics that expose the laser source, may result in direct exposure to laser

radiation and the risk of permanent eye damage. Removal or modication of

the diffuser in front of the laser optic may result in the risk of permanent eye damage.

This device emits laser radiation. Use of controls or adjustments or

performance of procedures other than those specied herein may result in

hazardous radiation exposure. This laser product is designated Class 1 during all procedures of operation. When the ranging feature of the device is activated, a laser emitter of a ranging module may emit laser radiation and the device should not be aimed toward anyone. Avoid looking toward the laser emitter or into the laser radiation (beam) when operating the device. It is advisable to turn off the ranging module when it is not in use. This device must be used only according to the directions and procedures described in this documentation. Do not leave this device within the reach of children.

CLASS 1 LASER PRODUCT Classied EN/IEC 60825-1 2014

This product is in conformity with performance standards for laser products

under 21 CFR 1040, except with respect to those characteristics authorized by Variance Number FDA-2016-V-2943 effective September 27, 2016.

 WARNING

 CAUTION

NOTICE

Table of Contents

LIDAR-Lite v3HP Operation Manual and Technical Specications ��1

Laser Safety ......................................................................................................1

Specications �� 2

Physical .............................................................................................................2

Water Resistance ..............................................................................................2

Electrical ............................................................................................................2

Performance ......................................................................................................2

Interface .............................................................................................................2

Laser ..................................................................................................................2

Connections �� 2

Wiring Harness ..................................................................................................2

I2C Connection Diagrams .................................................................................2

Standard I2C Wiring ....................................................................................2

Standard Arduino I2C Wiring .......................................................................3

PWM Wiring .................................................................................................3

PWM Arduino Wiring....................................................................................3

Operational Information �� 4

Technology ........................................................................................................4

Theory of Operation ...........................................................................................4

Interface .............................................................................................................4

Initialization ..................................................................................................4

Power Enable Pin ........................................................................................4

I2C Interface ................................................................................................4

Mode Control Pin .........................................................................................4

Settings ........................................................................................................4

I2C Protocol Information �� 6

I2C Protocol Operation ......................................................................................7

Read Operation ...........................................................................................7

Write Operation ............................................................................................7

Control Register List ....................................................................................7

Detailed Control Register Denitions ...........................................................8

Frequently Asked Questions �� 10

How do I use the device for fast-scanning applications? .................................10

Does the device operate only on 5 Vdc? .........................................................10

What is the spread of the laser beam? ............................................................10

How do distance, target size, aspect, and reectivity affect returned signal

strength? ..........................................................................................................10

How does the device work with reective surfaces? ....................................... 11

Diffuse Reective Surfaces ........................................................................ 11

Specular Surfaces .....................................................................................11

How does liquid affect the signal? ................................................................... 11

Specications

Connections

Physical

Specication Measurement

Size (LxWxH) 20 × 48 × 40 mm (0.8 × 1.9 × 1.6 in.)

Weight 22 g (0.78 oz.)

Operating temperature -20 to 60°C (-4 to 140°F)

Water Resistance

Body of this device is rated IPX7, and can wthstand incidental exposure to water of up to 1 meter for up to 30 minutes.

IMPORTANT: The bare wire portion of the wiring harness is not water resistant, and can act as a path for water to enter the device. All bare-wire connections must either be made in a water-tight location or properly sealed.

Water may enter under the transmitting lens. This could affect performance,

but will not affect IPX7 water resistance.

Electrical

Specication Measurement

Power 5 Vdc nominal

4.5 Vdc min., 5.5 Vdc max.

Current consumption 65 mA idle

85 mA during an acquisition

Performance

Specication Measurement

Range (70% reective target) 40 m (131 ft)

Resolution +/- 1 cm (0.4 in.)

Accuracy < 2 m ±5 cm (2 in.) typical*

Accuracy ≥ 2 m ±2.5 cm (1 in.) typical

Mean ±1% of distance maximum Ripple ±1% of distance maximum

Update rate (70% Reective Target) Greater than 1 kHz typical

Reduced sensitivity at high update rates

*Nonlinearity present below 1 m (39.4 in.)

Interface

Specication Measurement

User interface I2C

PWM External trigger

I2C interface Fast-mode (400 kbit/s)

Default 7-bit address 0x62

Internal register access & control

PWM interface External trigger input

PWM output proportional to distance at 10 μs/cm

Laser

Specication Measurement

Wavelength 905 nm (nominal)

Total laser power (peak) 1.3 W

Mode of operation Pulsed (256 pulse max. pulse train)

Pulse width 0.5 μs (50% duty cycle)

Pulse train repetition frequency 10-20 kHz nominal

Energy per pulse <280 nJ

Beam diameter at laser aperture 12 × 2 mm (0.47 × 0.08 in.)

Divergence 8 mRad

Wiring Harness

Wire Color Function

Red 5 Vdc (+)

Orange Power enable (internal pull-up)

Yellow Mode control

Green I2C SCL

Blue I2C SDA

Black Ground (-)

There are two basic congurations for this device:

• I2C (Inter-Integrated Circuit)—a serial computer bus used to communicate between this device and a microcontroller, such as an Arduino board (I2C Interface, page 4).

• PWM (Pulse Width Modulation)—a bi-directional signal transfer method that triggers acquisitions and returns distance measurements using the mode-control pin (Mode Control Pin, page 4).

I2C Connection Diagrams

Standard I2C Wiring

➊

➋

➌ ➍

➎

➏ ➐

Item Description Notes

680µF electrolytic capacitor You must observe the correct polarity when

➊

Power ground (-) connection Black wire

➋

I2C SDA connection Blue wire

➌

I2C SCL connection Green wire

➍

4.7kΩ pull-up resistor

➎

(not required in all applications)

5 Vdc power (+) connection Red wire

➏

Logic rail connection The pull-up resistors connected to both I2C

➐

installing the capacitor.

In installations with long cable extensions

or with multiple devices on the I2C bus, you must install a 1kΩ to 10kΩ pull-up resistor on each I2C wire to account for cable

capacitance.

It is recommended to start with 4.7kΩ

resistors and adjust if necessary.

The sensor operates at 4.75 through 5.5 Vdc, with a max. of 6 Vdc.

wires must connect to the logic rail on your microcontroller board.

Standard Arduino I2C Wiring

➊

➋

➌

➍

PWM Arduino Wiring

➊

➋

➎

➐

➏

Item Description Notes

680µF electrolytic capacitor You must observe the correct polarity when

➊

Pull-up resistor connection

➋

(not required in all applications)

4.7kΩ pull-up resistor

➌

(not required in all applications)

I2C SDA connection Blue wire

➍

I2C SCL connection Green wire

➎

5 Vdc power (+) connection Red wire

➏

Power ground (-) connection Black wire

➐

installing the capacitor.

In installations with long cable extensions

or with multiple devices on the I2C bus, you

must connect the pull-up resistors on the SDA and SCL wires to the logic rail on your microcontroller board.

On an Arduino board, this is the 5v pin.

In installations with long cable extensions

or with multiple devices on the I2C bus, you must install a 1kΩ to 10kΩ pull-up resistor on each I2C wire to account for cable

capacitance.

It is recommended to start with 4.7kΩ

resistors and adjust if necessary.

The sensor operates at 4.75 through 5.5 Vdc, with a max. of 6 Vdc.

➌

➍ ➎

Item Description Notes

5 Vdc power (+) connection Red wire

➊

Power ground (-) connection Black Wire

➋

Mode-control connection Yellow wire

➌

Monitor pin on microcontroller Connect one side of the resistor to the mode-

➍

Trigger pin on microcontroller Connect the other side of the resistor to the

➎

1kΩ resistor

➏

The sensor operates at 4.75 through 5.5 Vdc, with a max. of 6 Vdc.

control connection on the device, and to a monitoring pin on your microcontroller board.

trigger pin on your microcontroller board.

➏

PWM Wiring

➊

➋

➌

➍

➎ ➏

Item Description Notes

Trigger pin on microcontroller Connect the other side of the resistor to the

➊

Monitor pin on microcontroller Connect one side of the resistor to the mode-

➋

Power ground (-) connection Black Wire

➌

1kΩ resistor

➍

Mode-control connection Yellow wire

➎

5 Vdc power (+) connection Red wire

➏

trigger pin on your microcontroller.

control connection on the device, and to a monitoring pin on your microcontroller.

The sensor operates at 4.75 through 5.5 Vdc, with a max. of 6 Vdc.

Operational Information

Technology

This device measures distance by calculating the time delay between the

transmission of a Near-Infrared laser signal and its reception after reecting off

of a target. This translates into distance using the known speed of light.

Theory of Operation

To take a measurement, this device rst performs a receiver adjustment

routine, correcting for changing ambient light levels and allowing maximum sensitivity.

The device sends a reference signal directly from the transmitter to the receiver. It stores the transmit signature, sets the time delay for “zero” distance, and recalculates this delay periodically after several measurements.

Next, the device initiates a measurement by performing a series of

acquisitions. Each acquisition is a transmission of the main laser signal while recording the return signal at the receiver. If there is a signal match, the result is stored in memory as a correlation record. The next acquisition is summed

with the previous result. When an object at a certain distance reects the

laser signal back to the device, these repeated acquisitions cause a peak to emerge, out of the noise, at the corresponding distance location in the correlation record.

The device integrates acquisitions until the signal peak in the correlation record reaches a maximum value. If the returned signal is not strong enough for this to occur, the device stops at a predetermined maximum acquisition count.

Signal strength is calculated from the magnitude of the signal record peak

and a valid signal threshold is calculated from the noise oor. If the peak is

above this threshold, the measurement is considered valid and the device will

calculate the distance. Otherwise, it will report 1 cm. When beginning the next

measurement, the device clears the signal record and starts the sequence again.

Interface

Initialization

On power-up or reset, the device performs a self-test sequence and initializes all registers with default values. After roughly 22 ms, distance measurements can be taken with the I2C interface or the Mode Control Pin.

Power Enable Pin

The enable pin uses an internal pullup resistor, and can be driven low to shut off power to the device.

I2C Interface

This device has a 2-wire, I2C-compatible serial interface (refer to I2CBus Specication, Version 2.1, January 2000, available from Philips Semiconductor). It can be connected to an I2C bus as a slave device, under the control of an I2C master device. It supports 400 kHz Fast Mode data

transfer.

The I2C bus operates internally at 3.3 Vdc. An internal level shifter allows the bus to run at a maximum of 5 Vdc. Internal 3k functionality and allow for a simple connection to the I2C host.

The device has a 7-bit slave address with a default value of 0x62. The effective 8-bit I2C address is 0xC4 write and 0xC5 read. The device will not respond to a general call. Support is not provided for 10-bit addressing.

The most signicant bit of the register is the byte that follows the I2C address in a normal transaction. Setting this most signicant bit of the I2C address byte

to one triggers automatic incrementing of the register address with successive

reads or writes within an I2C block transfer. This is commonly used to read the two bytes of a 16-bit value within one transfer and is used in the following

example.

The simplest method of obtaining measurement results from the I2C interface is as follows:

Write 0x04 to register 0x00.

Read register 0x01. Repeat until bit 0 (LSB) goes low.

Ω pullup resistors ensure this

Read two bytes from 0x8f (High byte 0x0f then low byte 0x10) to obtain the

16-bit measured distance in centimeters.

A list of all available control resisters is available on page 7.

For more information about the I2C protocol, see I2C Protocol Operation

(page 7).

Mode Control Pin

The mode control pin provides a means to trigger acquisitions and return the measured distance via Pulse Width Modulation (PWM) without having to use

the I2C interface.

The idle state of the mode control pin is high impedance (High-Z). Pulling the mode control pin low will trigger a single measurement, and the device will respond by driving the line high with a pulse width proportional to the

measured distance at 10 μs/cm. A 1k

prevent bus contention.

The device drives the mode control pin high at 3.3 Vdc. Diode isolation allows the pin to tolerate a maximum of 5 Vdc.

As shown in the diagram PWM Arduino Wiring (page 3), a simple triggering method uses a 1k the mode control pin low to initiate a measurement, and a host input pin connected directly to monitor the low-to-high output pulse width.

If the mode control pin is held low, the acquisition process will repeat

indenitely, producing a variable frequency output proportional to distance. The mode control pin behavior can be modied with the ACQ_CONFIG_REG

(0x04) I2C register as detailed in 0x04 (page 8).

Ω termination resistance is required to

Ω resistor in series with a host output pin to pull

Settings

The device can be congured with alternate parameters for the distance

measurement algorithm. This can be used to customize performance by

enabling congurations that allow choosing between speed, range, and sensitivity. Other useful features are also detailed in this section. See the full

Control Register List (page 7) for additional settings.

Acquisition Command

Address Name Description Initial Value

0x00 ACQ_COMMAND Device command --

• Writing any non-zero value initiates an acquisition.

Maximum Acquisition Count

Address Name Description Initial Value

0x02 SIG_COUNT_VAL Maximum acquisition count 0xFF

The maximum acquisition count limits the number of times the device will

integrate acquisitions to nd a correlation record peak (from a returned signal), which occurs at long range or with low target reectivity. This controls the

minimum measurement rate and maximum range. The unit-less relationship

is roughly as follows: rate = 1/n and range = n^(1/4), where n is the number of

acquisitions.

Measurement Quick Termination Detection

Address Name Description Initial Value

0x04 ACQ_CONFIG_REG Acquisition mode control 0x08

You can enable quick-termination detection by clearing bit 3 in this register (starting with the LSB in this register as bit 0). The device will terminate

a distance measurement early if it anticipates that the signal peak in the correlation record will reach maximum value. This allows for faster and slightly

less accurate operation at strong signal strengths without sacricing long

range performance.

Detection Sensitivity

Address Name Description Initial Value

0x1c THRESHOLD_

BYPASS

The default valid measurement detection algorithm is based on the peak value, signal strength, and noise in the correlation record. This can be overridden to become a simple threshold criterion by setting a non-zero value.

Recommended non-default values are 0x20 for higher sensitivity with more

Peak detection threshold bypass 0x00

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