v1.1.0 - Updated July 18, 2013

AVIT2 - User Guide

Federal Communications Commission Statement (Pending Approval)

This device complies with Part 15 of the FCC Rules. Operation is subject to the following

two conditions:

• This device may not cause harmful interference.

• This device must accept any interference received, including interference that may

cause undesired operation.

This equipment has been tested and found to comply with the limits for a class B digital

device, pursuant to part 15 of the FCC Rules. These limits are designed to provide

reasonable protection against harmful interference in a residential installation.

This equipment generates uses and can radiate radio frequency energy and, if not

installed and used in accordance with the instructions, may cause harmful interference to

radio communications. However, there is no guarantee the interference will not occur in a

particular installation. If this equipment does cause harmful interference to radio or

television reception, which can be determined by turning the equipment off and on, the

user is encouraged to try to correct the interference by one or more of the following

measures:

• Reorient or relocate the receiving antenna.

• Increate the separation between the equipment and the receiver.

• Connect the equipment into an outlet on a circuit different from that to which the

receiver is connected.

• Consult the dealer or an experienced radio/TV technician for help.

CAUTIO�: Any changes or modifications not expressly approved by the party

responsible for compliance could void the user’s authority to operate the equipment.

Prohibition of Co-location

This device and its antenna(s) must not be co-located or operating in conjunction with

any other antenna or transmitter.

Safety Information

To maintain compliance with FCC’s RF exposure guidelines, this equipment should be

install and operated with minimum distance 20cm between the radiator and your body.

Use the supplied or recommended antenna.

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Quick Start • Default user and password: root / powerful

• Serial port console (labeled HUD): 115200,8,N,1

• By default the SSH server started and is listening on all network connections.

• There is no telnet server installed.

• Ethernet port 0 by default obtains an IPv4 address via DHCP server or will use avahi

zeroconf if a DHCP server is not found on the network. The default multicast DNS

name of avit2-xxx.local will be advertised where xxx represents the serial number of

the avit2 device.

• Ethernet port 1 by default uses a static IP address of 192.168.43.1 and starts the built

in DHCP server which will serve one IP address.

Configuration Most of the AVIT2 configuration parameters can be modified via the AVIT2 built in web

server Boot Options selection. To learn about connecting to the AVIT2, go to the

Network Connections and default settings section of this guide.

Autorun By default autorun is enabled and allows for launching of applications automatically

when the avit2 is booted. The autorun file path and name must be /opt/etc/autorun and the

files permissions set to executable. The autorun file is launched very early in the boot

process and it is likely that all of the systems resources that your application requires are

not yet available. It is up to the user to wait on such resources to become available or

code your application to handle such accordingly.

Internal Flash Storage There is 512MB of internal flash storage which by default is writeable, utilizes UBIFS

wear leveling and is mounted as “/opt”. The intention of this storage is for storing

application, configuration files and a moderate amount data logging. As a bonus, the

“/opt/bin” directory is included in the executable search path by default.

MicroSD Storage The MicroSD slot can be found of the front of the avit2. The MicroSD card can be

formatted as one of the various FAT or EXT formats and seems to work fine with all of

the MicroSD cards that we have tried. By default, the MicroSD card will be automatically

be mounted as “/mnt/uSD” when inserted or found at boot up. Before removing the

MicroSD card you will want to insure that your application has flushed all data being

written to the card and if possible unmount the card.

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USB Storage Devices The avit2 includes support for USB storage devices. These devices will automatically be

dynamically mounted when they are plugged into any of the USB host ports or

discovered at boot time. The mount point of each device is “/mnt/usbX” where X

correlates to the USB port number which are numbered 0 and 1 for the base unit and 2

thru 9 for the optional USB expansion board.

SATA Solid State Disk (optional) The optional SATA SSD slot is internal to the avit2 device and is not designed to be user

installable or replicable. By default the SATA drive is formatted as EXT4 will be

automatically mounted as “/mnt/sata” if discovered at boot up.

Real Time Clock/Time Zone Setting The avit2 has a battery backed real time clock which is used automatically at boot to

initialize the Linux system date and time. In order to set the RTC you first set the Linux

date and time via the date, ntpdate or such commands and then run “hwclock -u -w” at

the command. The avit2 expects that the RTC is set to UTC and uses the time-zone

preference set using Boot Options web page. Some typical gmt_offset settings would be

“EST5EDT” for Eastern Time and “PST8PDT” for Pacific Time. The default setting is

“UTC0” with no adjustment for daylight saving time.

SSH The avit2 utilizes the OpenSSH server and client suite which includes sshd, sftpd, ssh,

sftp, scp and utilities. The regular set of OpenSSH configuration and key files can be

found in the /opt/etc/ssh directory. The SSH sever is enabled by default but can be

disabled/enabled via the Boot Options web page.

HTTP Server The avit2 implements a basic HTTP server which can be extended to incorporate a

customized web interface for your applications. The avit2 specific html and cgi files are

populated at boot with the html files being located in the “/www” directory and the cgi-

bin files located in the “/www/cgi-bin” directory.

The HTTP server configuration can be easily extended by placing user html files in the

“/opt/www” directory and any user cgi-bin files in the “/opt/cgi-bin” directory and are

exposed “via /user/*” and “/cgi-bin/user/*” respectively.

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GPS (Optional) The avit2 has a GPS receiver build into the optional 3-in-1 Cellular, WiFi, and GPS

module. In order for the GPS to work a GPS antenna must be connected to the GPS

antenna connector on the back of the avit2 and the GPS started by executing the “gps

start” command.

Once the GPS device has been started, NEMA GPS sentences should now be available by

reading the /dev/ttyHS1 device (i.e. cat /dev/ttyHS1). The antenna needs to see “clear

sky”, which means that antenna should be positioned horizontally on the vehicles roof or

dashboard.

Cellular 3G (Optional) The optional Option GTM679W module adds support for high-speed multi-mode 3G

CDMA/GSM/GPRS/EDGE/UMTS/HSPA network connectivity. There is a hidden SIM

card slot behind the front panel which must be populated. Use caution regarding the

LEDs and buttons when removing and installing the front panel.

There is a “hso-connect” bash script which can be used as-is or as a template for

establishing cellular connectivity to your carrier. Use the boot options webpage of your

avit2 to set the APN and other parameters necessary for your carrier.

Digital Outputs The AVIT2 has two isolated digital outputs which can switch up to a maximum of 24

Volts and is protected by a 1 AMP self resetting fuse. Each set of digital switch

connections have an input and an output pin. Enabling the digital output simply connects

the in pin to the out pin acting like a bidirectional switch. See Digital I/O connector for

the pin out.

# shell script example that sets Digital Output 1 to ON and Digital Output 2 to OFF

echo 1 > /sys/class/gpio/gpio92/value

echo 0 > /sys/class/gpio/gpio93/value

Digital Inputs The AVIT2 has 3 digital inputs. The approximate trigger voltage for the digital inputs is

1.5 volts and a maximum of 40 volts. The digital inputs are implemented using input

events which are not easily exposed like the digital output. However, an example of how

the digital inputs can be use is provided in the button.c source which is included in avit2-

samples.tgz archive.

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�etwork Connections and default settings:

Most all of the networking settings can be changed using the “Boot Options” web page.

The information below discusses mainly the default settings, useful to get you initially

connected to the AVIT2 device.

AVAHI multicast D�S/D�S-SD service discovery - Is configured for all network

interfaces. A DNS name of "HOSTNAME.local" will be advertised where

“HOSTNAME” is the actual hostname of the AVIT2 device (i.e. avit2-100.local).

Ethernet port 0 (10/100/1000 Mbps) – By default eth0 will attempt to obtain its IP via

DHCP. If a DHCP server is not found on the network, AVAHI will assign a link-local IP

address (169.254.0.0/16).

Ethernet port 1 (10/100/1000 Mbps) - By default eth1 is assigned a static IP address of

192.168.43.1 and a DHCP server is started and will serve 1 IP address of 192.168.43.102.

By default the DHCP server is configured to only provide 1 IP address to reduce the

exposure of someone accidentally connecting this port to a network which already has a

DHCP server.

Wireless LA� - wlan0 (802.11b/g/n) - By default the WLAN device is configured to

work in managed/infrastructure mode (connects to an access-point). Support for

additional modes will be added as needed. The WLAN device can be configured to

operate with a single antenna or two antennas for improved performance.

By default when wlan0 is enabled, the wpa_supplicant daemon is automatically started.

The wpa_supplicant is needed for connecting to a secure access point via WPA, WEP or

such. The default configuration file is “/etc/wpa_supplicant.conf” and is provided as a

sample that will most likely need to be modified for it to be useful in your environment.

To modify the wpa_supplicant.conf you will need to copy the file to

“/opt/etc/wpa_supplicant.conf” which is writeable area. Once modified, a reboot of the

device is necessary for the changes to take affect.

USB Gadget Ethernet (Not supported for 64bit versions of Windows) – If enabled the

USB device port can be used to establish network connectivity between the avit2 and host

computer over USB. By default usb0 is configured to automatically establish a link-local

IP address and can communicate with other hosts that support the same.

• Windows requires that the RNDIS Ether Gadget (linux.inf) and the Bonjour SDK

installed.

• Linux (Ubuntu) requires only that the USB connection be changed from DHCP to

link-local in the Connection Manager.

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Front Panel Switches The AVIT2 has two recessed switches that are labeled S1 and S2 that are located just left

of the LEDs.

Switch Function

S1 Reboot

S2 Power Off

Front Panel LEDs The AVIT2 front panel contains six bi-color LEDs. The LED labeled A is dedicated to

displaying the status of the Board Monitor Controller. The next four LEDs labeled B thru

E are available user applications. The last LED, which is labeled F, is for the optional

SATA disk drive.

LED A (Board Monitor Controller LED) – The usage of this LED for displaying the

BMC status. See the table below for a description of the various LED A states.

LED A Condition Description

Green flashing 95% On Normal ON state

Green flashing 95% Off Normal OFF state

Green heartbeat Sleep Wake-On-CAN state

Red patterns (i.e. blink 3

times, pause, blink 5

times, long pause,

repeat)

Used to indicate that an internal power supply is not within

specifications. Verify that the unit has been upgraded to the

latest firmware. If the issue persists, please contact Drew

Technologies, Inc. for further assistance.

Red Flashing ~5Hz Make sure that SW1 is not stuck. Or something maybe wrong

with the BMC firmware, try updating the firmware. If the

issue persists, please contact Drew Technologies, Inc. for

further assistance.

Green/Red Cycling Make sure that SW2 is not stuck. Or something maybe wrong

with the BMC firmware, try updating the firmware. If the

issue persists, please contact Drew Technologies, Inc. for

further assistance.

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LED B thru E (User LEDs) – The front panel bi-color (Red/Green) user LEDs B, C, D

& E are exposed as /sys/class/leds led2-led5 respectively and can be controlled

programmatically.

Below is an example that uses shell commands but a C or C++ application can be created

just well (see sample avit2 applications).

# Turn on LED5 (E) as red.

echo 1 > /sys/class/leds/avit2:red:led5/brightness

# Turn off LED5 (E) as red.

echo 0 > /sys/class/leds/avit2:red:led5/brightness

# Turn on LED5 (E) as green.

echo 1 > /sys/class/leds/avit2:green:led5/brightness

LED F (SATA Disk Activity LED) – This LED is dedicated to displaying SATA hard

drive disk activity.

Buzzer Usage The AVIT2 contains an internal fixed frequency buzzer which is controlled similar to the

“User LEDs”.

# Turn ON buzzer.

echo 1 > /sys/class/leds/avit2:buzzer/brightness

# Turn OFF buzzer.

echo 1 > /sys/class/leds/avit2:buzzer/brightness

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CA� Channels

In your j2534 application you can use any of the following three approaches to access the

avit2 CAN channels:

1. For a simple program you may call PTConnect for ProtocolID = CAN or ISO15765.

This creates a logical channel on pins 6 & 14.

retval = PassThruConnect(DeviceID, ISO15765, ConnectFlags,

500000, &ChannelID);

assert(retval == STATUS_NOERROR);

2. For a more complex program you may connect on a ProtocolID = CAN_PS or

ISO15765_PS. This creates an unassigned logical channel. Then set config J1962_PINS

with pair of pins to choose a specific CAN circuit and bind the logical channel to it.

retval = PassThruConnect(DeviceID, ISO15765_PS, ConnectFlags,

500000, &ChannelID);

assert(retval == STATUS_NOERROR);

ConfigList.ConfigPtr = &Config;

ConfigList.NumOfParams = 1;

Config.Parameter = J1962_PINS;

Config.Value = 0x060E;

retval = PassThruIoctl(ChannelID, SET_CONFIG, &ConfigList, NULL);

assert(retval == STATUS_NOERROR);

Note: AVIT2 is capable of reading "Cable ID" bits to verify that it's plugged into the

correct type of cable. Although it does not currently, we may at some point read the ID

and enforce this call succeeds only when a J1962 cable is connected. Alternate cables

might require a different Config.Parameter like CUSTOM_CABLE_PINS.

3. Alternately you may connect on ProtocolID=CAN_CH1 or ISO15765_CH1 and avoid

the call for J1962_PINS. This creates a logical channel similar to #1 but each _CHx value

specifies one of the 7 possible CAN controllers.

retval = PassThruConnect(DeviceID, ISO15765_CH1, ConnectFlags,

500000, &ChannelID);

assert(retval == STATUS_NOERROR);

There are quite a few options, so I hope this list is self-explanatory:

CAN or CAN_PS(0x060E) or CAN_CH1 == 6/14 on DB-26

CAN_PS(0x030B) or CAN_CH2 == 3/11 on DB-26

CAN_PS(0x0C0D) or CAN_CH3 == 12/13 on DB-26

CAN_PS(0x0809) or CAN_CH4 == 8/9 on DB-26 only if daughtercard present

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CAN_PS(0x1314) or CAN_CH5 == 19/20 on DB-26 only if daughtercard present

CAN_PS(0x1516) or CAN_CH6 == 21/22 on DB-26 only if daughtercard present

CAN_PS(0x1718) or CAN_CH7 == 23/24 on DB-26 only if daughtercard present

Note: libavt432 enforces everything as described in J2534 meaning that:

• A single program can mix-and-match any combination of calls. For example a single

program is permitted to make these calls to connect on 3 different channels:

PTConnect(CAN), PTConnect and J1962_PINS(0x030B), and

PTConnect(CAN_CH3)

• But if you've called PTConnect(CAN) it enforces that any subsequent

J1962_PINS(0x060E) or CAN_CH1 call will fail. It knows they all refer to the same

physical resource

• You may call PTConnect() a maximum of 3 times when there are 3 pieces of

hardware available, or 7 times when there are 7 pieces of hardware available. It tracks

how many logical channel IDs have been handed out; whether or not they have been

assigned to pins.

• The libavt432 library detects if the CAN expansion card is present, so it will fail any

calls for _CH4, _CH5, _CH6, and _CH7 when the hardware is not installed.

There's no API call to check if a CAN expansion card is present, but there is an API to

see if a CAN channel can be opened on a specific set of pins:

SPARAM_LIST ParamList;

SPARAM Param;

ParamList.NumOfParams = 1;

ParamList.ParamPtr = &Param;

Param.Parameter = ISO15765_PS_J1962;

Param.Value = 0x060E;

retval = PassThruIoctl(DeviceID, GET_DEVICE_INFO, NULL, &ParamList);

assert(retval == STATUS_NOERROR);

// Check Param.Supported

In this way you can be certain that the AVIT2 has a CAN expansion installed and would

support a PTConnect or J1962_PINS call for the additional CAN controllers.

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AVIT2 Firmware Updates

From time to time new firmware updates will become available. The current firmware

should always be available to download at “http://drewtech.com/downloads/avit2”. To

update the AVIT2, simply save the AVIT2 firmware file to your computers desktop and

then use the “Update Firmware” option in the AVIT2 internal web tool.

AVIT2 Software Development Kit (SDK)

The AVIT2 SDK consists of a GCC C and C++ cross compiler tool chain tailored for the

AVIT2, j2534 and supporting libraries.

The current AVIT2 SDK and sample programs and can be downloaded from the

http://drewtech.com/downloads/avit2 webpage.

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Analog Board (Optional) The option Analog board supports either 16 analog single ended inputs or 8 differential

inputs with input voltage range from -10 to +10 volts.

The analog setup commands are modeled after the J2534-2 analog commands which

should be used as a reference. This section expands on items that are additional or

different from the specification. An important note is that the sample rate parameter

needs to be set last. Setting the sample rate to non-zero is what starts the analog

subsystem. If it's necessary to change any parameters after the ADC subsystem has been

started, the sample rate should be set to 0 first, otherwise an error will be returned.

The ADC subsystem is made up of two A/D converters, each of which can connect to up

to 8 channels. Each of the A/D converters can do a maximum aggregate sample rate of

100,000 samples per second for a maximum of 200,000 samples per second for the whole

subsystem. If there are 8 channels active on a converter, the maximum sample rate for

each channel is 12,500 samples per second. The sample rate and sample type

(differential/single ended) for both of the A/D converters must be the same.

If your application does not read data fast enough, the ADC subsystem is stopped and

restarted when an inbound data buffer becomes available again. There is a single Ioctl

for control, CLEAR_RX_BUFFER which can be used to clear stale data from the

inbound data buffer.

J2534-2 PassThruIoctl SET_CONFIG parameter commands are used to set up the ADC

operating parameters. Here are the parameters and their meanings:

ACTIVE_CHANNELS: This parameter sets both the channels that are open and the

channel type (single ended or differential). The lower 16 bits activates channels for

single ended (common ground) operation. The upper 16 bits activates channels for

differential operation. All active channels must be defined in either the lower 16 bits or

the upper 16 bits with no mixing. Attempting to mix single ended/differential channels

will result in an error.

Differential channels can be enabled with either channel of the channel pair (odd/even

pin pair) being the positive or negative lead (channel polarity selection). Attempting to

set a channel to both polarities will result in an error.

Examples:

ACTIVE_CHANNELS = 0x0000ffff – 16 active single ended channels

ACTIVE_CHANNELS = 0x55550000 – 8 active differential inputs normal polarity

ACTIVE_CHANNELS = 0xaaaa0000 – 8 active differential inputs reversed polarity

ACTIVE_CHANNELS = 0xffff0000 – Invalid

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SAMPLE_RATE: This sets the sample rate for each of the activated channels. The

maximum sample rate is dependent on the number of channels activated. The A/D bank

with the largest number of active channels determines the maximum sample rate for both

converters:

1 active channel - 100,000 samples per second per bank per channel

2 active channels - 50,000 samples per second per bank per channel

3,4 active channels - 25,000 samples per second per bank per channel

5+ active channels - 12,500 samples per second per bank per channel

At this time the minimum sample rate is 1 sample per second.

SAMPLES_PER_READING: This indicates how many samples to take for each reading

that's put in the message. 1 is set by default. If this number is set to > 1, then the

parameter AVERAGING_METHOD determines how the final reading is determined

from the samples.

AVERAGING_METHOD: Used when SAMPLES_PER_READING > 1.

0 - Simple Averaging (Sum(Samples)/number of samples) – Default

1 - Max Limit (choose largest magnitude sample)

2 - Min Limit (choose smallest magnitude sample)

3+ - Not supported

READINGS_PER_MSG: Number of samples for each active channel to send in each

read message. The number of active channels * Readings Per Message must be <= 1032.

This parameter set to 1 by default.

SAMPLE_RESOLUTION: Read Only, 16 bit sample resolution.

INPUT_RANGE_LOW: Read Only, -10000mV.

INPUT_RANGE_HIGH: Read Only, +10000mV.

DT_INPUT_RANGE_SELECT: Not supported at this time. Defaults to +/-10V

DT_ADC_INT_WINDOW: Sets the minimum number of microseconds between ADC

Doorbell interrupts for data packets. This parameter set to 0 by default and only used in

very rare instances.

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Serial port/HUD Connector

RS232 wired as DCE (Female - like a modem or peripheral on DB9): 1:

2: Transmit data (avit2 output, PC input)

3: Receive data (avit2 input, PC output)

4:

5: GND

6:

7: CTS

8: RTS

9: Switched vehicle voltage for DashDAQ-HUD protected by 1 amp self resetting fuse.

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Vehicle Connector

Vehicle Connector pinout(DB-26):

Base Pins

Shell: Case Ground 12: CAN3_H

3: CAN2_H 13: CAN3_L

4: Vehicle chassis ground (see SAE J1962) 14: CAN1_L

5: Signal ground (see SAE J1962) 16: Vehicle Voltage (input)

6: CAN1_H 17: Cable ID 0 (Contact DrewTech)

11: CAN2_L 18: Cable ID 1 (Contact DrewTech)

Optional – 4 Channel HS_CAN Pins

8: CAN4_H 21: CAN6_H

9: CAN4_L 22: CAN6_L

19: CAN5_H 23: CAN7_H

20: CAN5_L 24: CAN7_L

Optional – Single Wire CAN / 2 Channel HS_CAN Pins:

8: CAN4_H 21: SW_CAN

9: CAN4_L 22: Unused

19 CAN5_H

20: CAN5_L

Optional – Fault Tolerant CAN / 2 Channel HS_CAN Pins:

8: CAN4_H 21: FT_CAN_H

9: CAN4_L 22: FT_CAN_L

19 CAN5_H

20: CAN5_L

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Digital I/O Connector

Digital I/O connector pin out (Male - DB9): 1: Switched output #1a (24V, 1A max)

2: Switched output #1b

3: Digital input #1

4: Digital input #3

5: Signal ground

6: Switched output #2a (24V, 1A max)

7: Switched output #2b

8: Digital input #2

9: Signal ground

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Analog Board Connector (Optional)

Analog connector pin out (DB25):

1: GND

2: AN2

3: AN3

4: GND

5: AN6

6: AN7

7: GND

8: AN10

9: AN11

10: GND

11: AN14

12: AN15

13: GND

14: AN1

15: GND

16: AN4

17: AN5

18: GND

19: AN8

20: AN9

21: GND

22: AN12

23: AN13

24: GND

25: AN16

Shell: Case is grounded