Vectornav VN-200 User manual

UM004
User manual
VN-200 Beta
Rev 0.1.3 1/47
VN -200 User Manual
Firmware v0.1.7.x

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Table of Contents
1Introduction.................................................................................. 5
1.1 Product Description.....................................................................................5
1.2 Product Features .........................................................................................5
1.3 Surface-Mount Package...............................................................................6
1.4 Rugged Package...........................................................................................6
1.5 Surface-Mount Development Kit................................................................. 6
1.6 VN-200 Rugged GPS/INS Development Kit..................................................7
1.7 Sensor Coordinate System........................................................................... 7
2Specifications ................................................................................ 8
2.1 VN-200 Surface-Mount Sensor (SMD) Electrical ......................................... 8
2.1.1 VN-200 SMD Power Supply..................................................................................... 10
2.1.2 VN-200 SMD Serial (UART) Interface...................................................................... 10
2.1.3 VN-200 SMD Serial Peripheral Interface (SPI) ........................................................ 10
2.1.4 VN-200 SMD Reset, SyncIn/Out, and Other General I/O Pins................................ 10
2.2 VN-200 Rugged Electrical ..........................................................................11
2.2.1 VN-200 Rugged Power Supply ................................................................................ 12
2.2.2 VN-200 Rugged Serial UART Interface.................................................................... 12
2.2.3 VN-200 Rugged Reset, SyncIn/Out, and Other General I/O Pins ........................... 12
2.3 VN-200 Surface-Mount Sensor (SMD) Dimensions ...................................13
2.4 VN-200 Rugged Dimensions ......................................................................14
2.5 Absolute Maximum Ratings.......................................................................14
3Basic Communication.................................................................. 15
3.1 Serial Interface ..........................................................................................15
3.2 Checksum / CRC.........................................................................................15
3.2.1 8-bit Checksum ....................................................................................................... 15
3.2.2 16-bit CRC................................................................................................................ 15
3.3 SPI Interface...............................................................................................16
4Communication Protocol............................................................. 19

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4.1 Numeric Formats.......................................................................................19
4.2 Single Precision Floating Points .................................................................19
4.3 Fixed-Point Numbers .................................................................................19
4.4 System Commands ....................................................................................20
4.4.1 Read Register Command......................................................................................... 20
4.4.2 Write Register Command ....................................................................................... 20
4.4.3 Write Settings Command........................................................................................ 21
4.4.4 Restore Factory Settings Command ....................................................................... 21
4.4.5 Reset Command...................................................................................................... 22
4.5 System Error Codes ...................................................................................23
5System Registers ......................................................................... 24
5.1 User Tag Register.......................................................................................25
5.2 Model Number Register ............................................................................26
5.3 Hardware Revision Register.......................................................................27
5.4 Serial Number Register..............................................................................28
5.5 Firmware Version Register ........................................................................29
5.6 Serial Baud Rate Register...........................................................................30
5.7 Async Data Output Type Register..............................................................31
5.8 Async Data Output Frequency Register.....................................................32
5.9 Magnetic and Gravity Reference Vectors ..................................................33
5.10 Reference Frame Rotation .....................................................................34
5.11 Communication Protocol Control...........................................................35
5.11.1 SerialCount.............................................................................................................. 35
5.11.2 SerialStatus ............................................................................................................. 36
5.11.3 SPICount.................................................................................................................. 36
5.11.4 SPIStatus ................................................................................................................. 36
5.11.5 SerialChecksum....................................................................................................... 37
5.11.6 SPIChecksum ........................................................................................................... 37
5.11.7 ErrorMode............................................................................................................... 37
5.12 Synchronization Control .........................................................................38

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5.12.1 SyncInMode ............................................................................................................ 38
5.12.2 SyncInEdge .............................................................................................................. 38
5.12.3 SyncInSkipFactor ..................................................................................................... 39
5.12.4 SyncOutMode ......................................................................................................... 39
5.12.5 SyncOutPolarity....................................................................................................... 39
5.12.6 SyncOutSkipFactor .................................................................................................. 39
5.12.7 SyncOutPulseWidth ................................................................................................ 40
5.13 Calibrated Sensor Measurements ..........................................................41
5.14 GPS Configuration ..................................................................................42
5.15 GPS Antenna Offset................................................................................43
5.16 GPS Solution ...........................................................................................44
5.17 INS Solution ............................................................................................45
6System Registers - Default Factory State ..................................... 46

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1Introduction
1.1 Product Description
The VN-200 is a miniature, surface-mount, high-performance Inertial Navigation System (INS).
Incorporating the latest solid-state MEMS sensor technology, the VN-200 combines 3-axis
accelerometers, 3-axis gyros, 3-axis magnetometer, a barometer, a 52-channel GPS receiver, and a 32-
bit processor into a miniature surface-mount module. Along with providing calibrated inertial sensor
measurements, the VN-200 also computes and outputs a real-time, high resolution 3D position, velocity
and drift-free orientation solution that is continuous over the complete 360 degrees of motion.
1.2 Product Features
The VN-200 is available in two different configurations, as a surface-mount sensor (VN-200 SMD), or as
an enclosed sensor (VN-200 Rugged). The VN-200 Rugged provides a robust, precision anodized
aluminum clamshell enclosure, ensuring precise alignment and calibration while still retaining the
smallest possible footprint.

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1.3 Surface-Mount Package
For embedded applications, the VN-200 is available in a
miniature surface-mount package.
Features
Small Size: 22 x 24 x 3 mm
Single Power Supply: 3.2 to 5.5 V
Communication Interface: Serial TTL & SPI
Low Power Requirement: < 330 mW @ 3.3V
1.4 Rugged Package
The VN-200 Rugged consists of the VN-200 sensor installed in a
robust precision aluminum enclosure.
Features
Precision aluminum enclosure
Locking 10-pin connector
Mounting tabs with alignment holes
Compact Size: 34 x 36 x 9 mm
Single Power Supply: 4.5 to 5.5 V
Communication Interface: Serial RS-232 & TTL
1.5 Surface-Mount Development Kit
The VN-200 Development Kit provides the VN-200 surface-
mount sensor installed onto a small PCB, providing easy access
to all of the features and pins on the VN-200. Communication
with the VN-200 is provided by either USB or RS-232 serial
communication ports. A 20-pin header provides easy access to
each of the critical pins. The VN-200 Development Kit also
includes all of the necessary cabling, documentation, and
support software.
Features
Pre-installed VN-200 Sensor
Onboard USB->Serial converter
Onboard TTL->RS-232 converter
30-pin 0.1” header for access to VN-200 pins
Power supply jack –5V (Can be powered from USB)
Board Size: 76 x 76 x 14 mm

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1.6 VN-200 Rugged GPS/INS Development Kit
The VN-200 Rugged Development Kit includes the VN-200
Rugged sensor along with all of the necessary cabling required
for operation. Two cables are provided in each Development
Kit: one for RS-232 communication and a second custom cable
with a built in USB converter. The Development Kit also
includes all of the relevant documentation and support
software.
Features
(1) VN-200 Rugged Sensor
(1) 10-foot RS-232 cable
(1) 6-foot USB connector cable
1.7 Sensor Coordinate System
The VN-200 uses a right-handed coordinate system: a positive yaw angle is defined as a positive right-
handed rotation around the Z-axis; a positive pitch angle is defined as a positive right-handed rotation
around the Y-axis; and a positive roll angle is defined as a positive right-handed rotation around the X-
axis. The axes direction with respect to the VN-200 module is shown in Figure 1.
Figure 1 - VN-200 Coordinate System

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2Specifications
2.1 VN-200 Surface-Mount Sensor (SMD) Electrical
Figure 2 –Pin assignments (top down view)

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Table 1 –VN-200 SMD Pin Assignments
Pin #
Pin Name
Description
1
GND
Ground.
2
GND
Ground.
3
GND
Ground.
4
GND
Ground.
5
TX2
Serial UART #2 data output. (sensor)
6
RX2
Serial UART #2 data input. (sensor)
7
TARE/RESTORE
Normally used to zero (tare) the attitude.
To tare, pulse high for at least 1 μs. During power on or device reset, holding
this pin high will cause the module to restore its default factory settings. As a
result, the pin cannot be used for tare until at least 5 ms after a
power on or reset. Internally held low with 10k resistor.
8
NC
Not used.
9
SYNC_OUT
Time synchronization output signal. See Section 5.12 for more details.
10
VIN
3.2 - 5.5 V input.
11
ENABLE
Leave high for normal operation. Pull low to enter sleep mode. Internally
pulled high with pull-up resistor.
12
TX1
Serial UART #1 data output. (sensor)
13
RX1
Serial UART #1 data input. (sensor)
14
RESV
Reserved for future use. Leave pin floating.
15
SYNC_IN_2
Reserved for future use. For backwards compatibility with older hardware
revisions this pin can be configured in software to operate as the time
synchronization input signal. For new designs it is recommended that
SYNC_IN (pin 22) is used instead. See Section 5.12 for more details.
16
SPI_SCK
SPI clock.
17
SPI_MOSI
SPI input.
18
GND
Ground.
19
SPI_MISO
SPI output.
20
REPRGM
Used to reprogram the module. Must be left floating or set to low for normal
operation. Pull high on startup to set the VN-200 in reprogram mode.
Internally held low with 10k resistor.
21
NRST
Microcontroller reset line. Pull low for > 20 μs to reset MCU. Internally
pulled high with 10k.
22
SYNC_IN
Time synchronization input signal. See Section 5.12 for more details.
23
SPI_CS
SPI slave select.
24
GPS_PPS
GPS time pulse. One pulse per second, synchronized at rising edge. Pulse
width is 100 ms.
25
VBAT
Optional GPS RTC battery backup. 1.4 V –3.6 V input.
26
RESV
Reserved for future use.
27
RESV
Reserved for future use.
28
GND
Ground.
29
GPS_RF
Optional GPS RF input for passive antenna. The surface-mount IPX (U.FL)
connector should be used with an active GPS antenna.
30
GND
Ground.

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2.1.1 VN-200 SMD Power Supply
The minimum operating supply voltage is 3.2 V and the absolute maximum is 5.5 V.
2.1.2 VN-200 SMD Serial (UART) Interface
The serial interface on the VN-200 operates with 3 V TTL logic.
Table 2 - Serial I/O Specifications
Specification
Min
Typical
Max
Input low level voltage
-0.5 V
0.8 V
Input high level voltage
2 V
5.5 V
Output low voltage
0 V
0.4 V
Output high voltage
2.4 V
3.0 V
2.1.3 VN-200 SMD Serial Peripheral Interface (SPI)
Table 3 - Serial I/O Specifications
Specification
Min
Typical
Max
Input low level voltage
-0.5 V
0.8 V
Input high level voltage
2 V
5.5 V
Output low voltage
0 V
0.4 V
Output high voltage
2.4 V
3.0 V
Clock Frequency
8 MHz
16 MHz
Close Rise/Fall Time
8 ns
2.1.4 VN-200 SMD Reset, SyncIn/Out, and Other General I/O Pins
Table 4 - NRST Specifications
Specification
Min
Typical
Max
Input low level voltage
-0.5 V
0.8 V
Input high level voltage
2 V
5.5 V
Weak pull-up equivalent resistor
30 kΩ
40 kΩ
50 kΩ
NRST pulse width
20 μs
Table 5 - SyncIn Specifications
Specification
Min
Typical
Max
Input low level voltage
-0.5 V
0.8 V
Input high level voltage
2 V
5.5 V
Input Frequency
200 Hz
200 Hz
1 kHz
Pulse Width
500 μs
Table 6 - SyncOut Specifications
Specification
Min
Typical
Max
Output low voltage
0 V
0.4 V
Output high voltage
2.4 V
3.0 V
Output high to low fall time
125 ns
Output low to high rise time
125 ns

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Output Frequency
1 Hz
200 Hz
2.2 VN-200 Rugged Electrical
Table 7 –VN-200 Rugged Pin Assignments
Pin #
Pin Name
Description
1
VCC
+5V (±0.5V)
2
TX1
RS-232 voltage levels data output from the sensor. (Serial UART #1)
3
RX1
RS-232 voltage levels data input to the sensor. (Serial UART #1)
4
SYNC_OUT
Output signal used for synchronization purposes. Software configurable
to pulse when ADC, IMU, or attitude measurements are available.
5
GND
Ground
6
TARE/RESTORE
Input signal used to zero the attitude of the sensor. If high at reset, the
device will restore to factory default state. Internally held low with 10k
resistor.
7
SYNC_IN
Input signal for synchronization purposes. Software configurable to
either synchronize the measurements or the output with an external
device.
8
TX2_TTL
Serial UART #2 data output from the device at TTL voltage level (3V).
9
RX2_TTL
Serial UART #2 data into the device at TTL voltage level (3V).
10
RESV
This pin should be left unconnected.
Figure 3 - VN-200 Rugged External Connector

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2.2.1 VN-200 Rugged Power Supply
The nominal power supply for the VN-200 Rugged is 5 V DC.
The VN-200 Rugged internally has overvoltage protection set at a fixed voltage of 5.8 V. Upon
an overvoltage event the protection circuitry will disable power to the VN-200 to reduce
possibility of damage to the voltage regulator onboard the VN-200.
2.2.2 VN-200 Rugged Serial UART Interface
Table 8 - Serial I/O Specifications
Specification
Min
Typical
Max
Input low level voltage
-25 V
Input high level voltage
25 V
Output low voltage
-5.0 V
-5.4 V
Output high voltage
5.0 V
5.5 V
Output resistance
300 Ω
10 MΩ
Data rate
1 Mbps
Pulse slew
300 ns
2.2.3 VN-200 Rugged Reset, SyncIn/Out, and Other General I/O Pins
Table 9 - NRST Specifications
Specification
Min
Typical
Max
Input low level voltage
-0.5 V
0.8 V
Input high level voltage
2 V
5.5 V
Weak pull-up equivalent resistor
30 kΩ
40 kΩ
50 kΩ
NRST pulse width
20 μs
Table 10 - SyncIn Specifications
Specification
Min
Typical
Max
Input low level voltage
-0.5V
0.8V
Input high level voltage
2V
5.5V
Input Frequency
200 Hz
200 Hz
1 kHz
Pulse Width
500 μs
Table 11 - SyncOut Specifications
Specification
Min
Typical
Max
Output low voltage
0 V
0.4 V
Output high voltage
2.4 V
3.0 V
Output high to low fall time
125 ns
Output low to high rise time
125 ns
Output Frequency
1 Hz
200 Hz

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2.3 VN-200 Surface-Mount Sensor (SMD) Dimensions
Figure 4 –VN-200 PCB Footprint*
* Measurements are in inches

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2.4 VN-200 Rugged Dimensions
Figure 5 –VN-200 Rugged Dimensions
* Measurements are in inches
2.5 Absolute Maximum Ratings
Table 12 - Absolute Maximum Ratings
Specification
Min
Max
Input Voltage
-0.3 V
5.5 V
Operating Temperature
-40 C
85 C
Storage Temperature
-40 C
85 C

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3Basic Communication
The VN-200 module supports two communication interfaces: serial and SPI. On the serial interface, the
module communicates over a universal asynchronous receiver/transmitter (UART) and uses ASCII text
for its command and data format. On the SPI interface, the VN-200 module communicates as a slave
device on a Serial Peripheral Interface (SPI) data bus and uses a binary command and data format. Both
interfaces support the complete command set implemented by the module. A general overview of the
command format for each interface is given in the next two Sections and formatting specific to each
command and associated parameters is provided in the protocol and register Sections (Section 4 & 5).
3.1 Serial Interface
On the serial interface, the VN-200 uses ASCII text for its command format. All commands start with a
dollar sign, followed by a five character command, a comma, command specific parameters, an asterisk,
a checksum, and a newline character. An example command is shown below:
$VNRRG,11*73
3.2 Checksum / CRC
The serial interface provides the option for either an 8-bit checksum or a 16-bit cyclic redundancy check
(CRC). In the event neither the checksum nor the CRC is needed, they can be turned off by the user.
3.2.1 8-bit Checksum
The 8-bit checksum is an XOR of all bytes between, but not including, the dollar sign ($) and asterisk (*).
All comma delimiters are included in the checksum calculation. The resultant checksum is an 8-bit
number and is represented in the command as two hexadecimal characters. The C function snippet
below calculates the correct checksum:
3.2.2 16-bit CRC
For cases where the 8-bit checksum does not provide enough error detection, a full 16-bit CRC is
available. The VN-200 uses the CRC16-CCITT algorithm. The resultant CRC is a 16-bit number and is
represented in the command as four hexadecimal characters. The C function snippet below calculates
the correct CRC:
unsigned char calculateChecksum(char* command, int length)
{
unsigned char xor = 0;
for(int i = 0; i < length; i++)
xor ^= (unsigned char)command[i];
return xor;
}

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3.3 SPI Interface
The SPI interface uses a lightweight binary message format. The start of a command is signaled by
pulling the VN-200’s slave select pin (pin 23) low. Both the slave select line and clock are active low.
The first byte transmitted to the module should be the command ID and then a variable number of
bytes will follow dependent on the type of command specified. A communication transaction can be
cancelled at any time by releasing the slave select pin. Pulling the pin low again will start a new
communication transaction. All binary data is sent to and from the slave with most significant bit (MSB)
first in little-endian byte order with pad bytes inserted where required to ensure 16-bit values are
aligned to two-byte boundaries and 32-bit values are aligned to 4-byte boundaries. For example, the
serial baud rate register with a value of 9600 (0x2580) would be sent across the SPI as a 0x80, 0x25,
0x00, 0x00. Data is requested from and written to the device using multiple SPI transactions.
Figure 6 –SPI Timing Diagram
unsigned short calculateChecksum(char* command, int length)
{
unsigned int i;
unsigned short crc = 0;
for(i=0; i<length; i++){
crc = (unsigned char)(crc >> 8) | (crc << 8);
crc ^= command[i];
crc ^= (u8)(crc & 0xff) >> 4;
crc ^= (crc << 8) << 4;
crc ^= ((crc & 0xff) << 4) << 1;
}
return crc;
}

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Figure 7 - SPI Data Diagram
A response for a given SPI command will be sent over the MISO line on the next SPI transaction. Thus
the data received by the Master on the MISO line will always be the response to the previous
transaction. For example, if Yaw, Pitch, Roll and Angular Rates are desired, then the necessary SPI
transactions would proceed as shown below:
SPI Transaction 1
Line
Bytes
Description
SCK
8 bytes
MOSI
01 08 00 00 00 00 00 00 (shown as hex)
Read register 8 (Yaw, Pitch, Roll)
MISO
00 00 00 00 00 00 00 00 (shown as hex)
No response
SPI Transaction 2
Line
Bytes
Description
SCK
16 bytes
MOSI
01 13 00 00 00 00 00 00 00 00 00 00 00 00 00 00
(shown as hex)
Read register 13 (Angular Rates)
MISO
00 01 08 00 39 8A 02 43 FD 43 97 C1 CD 9D 67 42
(shown as hex)
Yaw, Pitch, Roll = -130.54, -18.91,
+57.90
SPI Transaction 3
Line
Bytes
Description
SCK
16 bytes
MOSI
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
(shown as hex)
No command
MISO
00 01 13 00 00 F5 BF BA 00 80 12 38 B8 CC 8D 3B
(shown as hex)
Rates = -0.001465, +0.000035,
+0.004327
During the first transaction the master sends the command to read register 8. The available registers
which can be read or written to are listed in Table 21 in Section 5. At the same time zeros are received
by the master, assuming no previous SPI command was sent to the VN-200 since reboot. On the second
transaction the master sends the command to read register 13. At the same time the response from the
previously requested register 8 is received by the master on the MISO line. It consists of four 32-bit
words. The first byte of the first word will always be zero. The second byte of the first word is the type
of command that this transaction is in response to. In this case it is a 0x01, which means that on the
previous transaction a read register command was issued. The third byte of the first word is the register
that was requested on the previous transaction. In this case it shows to be 0x08, which is the yaw, pitch,
roll register. The fourth byte of the first word is the error code for the previous transaction. Possible

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error codes are listed in Table 20 in Section 4.5. The remaining three 4-byte words are the yaw, pitch,
and roll respectively given as single-precision floating-point numbers. The floating-point numbers are
consistent with the IEEE 754 standard. On the third SPI transaction, 16 bytes are clocked on the SCK
line, during which zeros are sent by the master as no further data is required from the sensor. These 16
bytes are clocked out the SPI for the sole purpose of reading the response from the previous read
register 13 command. The response consists of four 32-bit words, starting with the zero byte, the
requested command byte, register ID, error code, and three single-precision floating-point numbers. If
only one register is required on a regular basis then this can be accomplished by sending the same
command twice to the VN-200. The response received on the second transaction will contain the most
up to date values for the desired register.
SPI Transaction 1
Line
Bytes
Description
SCK
16 bytes
MOSI
01 08 00 00 00 00 00 00 00 00 00 00 00 00 00
00 (shown as hex)
Read register 8 (Yaw, Pitch, Roll)
MISO
00 01 08 00 39 8A 02 43 FD 43 97 C1 CD 9D 67
42 (shown as hex)
Yaw, Pitch, Roll = +130.54, -18.91, +57.90
SPI Transaction 2
Line
Bytes
Description
SCK
16 bytes
MOSI
01 08 00 00 00 00 00 00 00 00 00 00 00 00 00
00 (shown as hex)
Read Register 8 (Yaw, Pitch, Roll)
MISO
00 01 08 00 C5 9A 02 43 51 50 97 C1 32 9A 67
42 (shown as hex)
Yaw, Pitch, Roll = +130.60, -18.91, +57.90
At first the device would be initialized by sending the eight bytes 01 08 00 00 00 00 00 00, requesting a
read of the yaw, pitch, roll register. The response from the second transaction would be the response to
the requested yaw, pitch, roll from the first transaction. The minimum time required between SPI
transactions is 50 µs.

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4Communication Protocol
The following Sections describe the serial and SPI data protocol used by the VN-200.
4.1 Numeric Formats
Floating-point numbers displayed as ASCII text are presented in two formats: single/double precision
floating-point and single/double precision fixed point. In order to conserve bandwidth each variable in
the register has associated with it either a floating or fixed point representation. Any time this variable
is accessed using a read/write register command or as Async output, the variable will always use its
associated data format.
4.2 Single Precision Floating Points
Single-precision floating-point numbers are represented with seven significant digits and a two digit
exponent. Both the sign of the number and exponent are provided. The decimal point will always
follow the first significant digit. An ‘E’ will separate the significant digits from the exponential digits.
Below are some samples of correct single-precision floating-point numbers:
Single Precision Floating Point Number Examples
+9.999999E+99
-7.344409E-05
-1.234567E+01
+4.893203E+00
4.3 Fixed-Point Numbers
The fixed-point representation consists of a specified number of digits to the left and right of a fixed
decimal point. The registers that use fixed point representation and their associated formatting are
listed below. It is important to note that all numeric calculations onboard the VN-200 are performed
with 32-bit or 64-bit IEEE floating-point numbers. For the sake of simplifying the output stream, some of
these numbers are displayed in ASCII as fixed point as described below.
Table 13 –Floating Point Representation
Variable Type
Fixed/Floating
Variable Size
Printf/Scanf
Example
Yaw, Pitch, Roll
Fixed
32-bit float
%+08.3f
+082.763
Quaternion
Fixed
32-bit float
%+09.6f
+0.053362
Magnetic
Fixed
32-bit float
%+07.4f
-0.3647
Acceleration
Fixed
32-bit float
%+07.3f
-09.091
Angular Rate
Fixed
32-bit float
%+09.6f
+00.001786
Latitude
Fixed
64-bit double
%+012.8f
+32.95614564

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4.4 System Commands
This Section describes the list of commands available on the VN-200 module. All commands are
available in both ASCII text (UART) and binary (SPI) command formats.
The table below lists the commands available along with some quick information about the commands.
The Text ID is used to specify the command when using the text command format and the Binary ID is
used to specify the command when using the binary command format. More details about the
individual commands can be found in the referenced Section.
Table 14 –List of Available Commands
Command Name
Text ID
Binary ID
Section
Read Register
VNRRG
0x01
4.4.1
Write Register
VNWRG
0x02
4.4.2
Write Settings
VNWNV
0x03
4.4.3
Restore Factory Settings
VNRFS
0x04
0
Reset
VNRST
0x06
4.4.5
4.4.1 Read Register Command
This command allows the user to read any of the registers on the VN-200 module (see Section 5 for the
list of available registers). The only required parameter is the ID of the register to be read. The first
parameter of the response will contain the same register ID followed by a variable number of
parameters. The number of parameters and their formatting is specific to the requested register. Refer
to the appropriate register Section contained in Section 5 for details on this formatting. If an invalid
register is requested, an error code will be returned. The error code format is described in Section 4.5.
Table 15 - Example Read Register Command
Example Command
Message
UART Command
$VNRRG,5*46
UART Response
$VNRRG,5,9600*65
SPI Command (8 bytes)
01 05 00 00 80 25 00 00 (shown as hex)
SPI Response (8 bytes)
00 01 05 00 80 25 00 00 (shown as hex)
4.4.2 Write Register Command
This command is used to write data values to a specified register on the VN-200 module (see Section 5
for the list of available registers). The ID of the register to be written to is the first parameter. This is
followed by the data values specific to that register. Refer to the appropriate register Section in Section
5 for this formatting. If an invalid register is requested, an error code will be returned. The error code
format is described in Section 4.5.