HDZERO Divimath Goggle User Manual

: September 9, 2024
: HDZERO

Table of Contents

HDZERO Divimath Goggle
References
Read User Manual Online (PDF format)
Download This Manual (PDF format)

HDZERO Divimath Goggle

Introduction

The HDZero Goggle is an all-in-one FPV goggle for digital, analog,, and HDMI video. Please take the time
to read through this operating manual thoroughly before using.

Diagram

Features
● Power on/off sliding switch – be confident that the goggles is on or off at a glance or by
feel
● Designed for open source, the new google runs Linux. All code for the user interface is
new and open-source
● Support diopter lens inserts
● 90Hz 1080p OLED screens with sliding IPD adjustment and dials for focus adjustment
● By integrating the entire google display pipeline with HDZero’s fixed- latency video
transmission, these goggles achieve 3ms glass-to-glass sub-frame latency with no jitter
or dropped frames
● Mounting rails for patch antennas or whatever else you might want to mount
● Recessed front SMA jacks so no need to remove antennas when packing the goggle
away
● Three independently addressable fans work in combination to cool the internals and
prevent fogging. They are soft mounted to prevent screen vibration and noise
● HDMI input and HDMI output
● Built-in microphone for DVR
● 3.5mm combination headphone / microphone jack for audio and external mic
● 3.5mm analog video/audio input for use with ground station inputs
● Integrated 2D deinterlacer that adds no delay for analog input
● Built-in ESP32
● Built-in H.265 DVR
● 6-axis smart inertial measurement for head tracking pan+tilt support
● Add-on side-mounted analog module bay that accepts most of today’s analog modules
● Add-on 2.4Ghz WiFi video streaming module for live streaming

Specification
● HDZero Camera glass-to-goggle glass latency: <3ms
● Adjust IPD range: 57-70mm
● Adjustable focus range: +6 to -6 diopter
● Full HD 1920x1080p 90fps OLED micro display
● FOV: 46deg
● Input voltage: 7V-25.2V
● Power consumption: 14.5W (with HDZero RF on), or 8.4W (with AV In)
● Weight: 294g
● Dimension: 185x81x66mm

Included Accessories
● 1x HDZero goggle
● 1x wide face plate
● 1x narrow face plate
● 1x foam padding
● 1x goggle strap
● 1x 1200mm XT60 cable
● 1x 150mm HDZero VTX programing cable
● 1x Thick Canvas Goggle Bag
● 1x Lens cloth

Setup
The HDZero goggle has many features that can be customized to the individual pilot.
Power Switch
There is a sliding power switch on the right side of the goggles. You may use it to turn on/off
the goggle, or just leave it on and plug/unplug the DC barrel plug to turn the goggle on and off.
In order to prevent voltage spikes entering the goggle, it is mandatory to plug in a 6S (max 4.2V
/cell) battery only if the power switch is off.
Power Input/Consumption
The goggle supports 7-25.2V power input 1
. Please make sure the power polarity is correct 2
(Center pin positive) before powering on the goggle.

TABLE 1. Power Consumption

Note:
1. DO NOT use a 6S or above HV lipo to power on the goggle, it will permanently damage
the goggle.
2. 18650 battery cases can kill your goggle (blow the fuse). Always install batteries in
correct polarity, check with case’s battery checker beforehand, if the checker lights
don’t turn on, the batteries are installed backwards and the goggle’s fuse will blow to
protect the goggle. This can be repaired by replacing the fuse inside the goggles, but at
owner’s own cost.
3. RapidFire is a product of ImmersionRC limited. It is not included.
XT60 Cable
The goggle includes a 1200mm XT60 cable for connecting a battery in your pocket. You may
also purchase a shorter 90mm cable on HDZero shop if you wish to locate your battery on the
goggle head strap.
The XT60 cable (either 1200mm or 90mm) has no voltage regulator. The cable passes voltage
directly through the goggle.

Note:
1. Do not connect an over 6S battery to the goggle, as the maximum voltage rating of the
goggle is 6S (4.2V/cell).
2. Some types of XT60 cable, i.e., HDZero VRX cable, has integrated DC regulators. Make
sure that cable is able to output enough current as indicate at Table 1. The goggle won’t
boot or keep rebooting if there if that happens.
Face Plate/Padding Foam
The goggle includes both a wide face plate and a narrow one. You may choose the appropriate
one to fit your face, and use the included 7mm thick foam padding for both comfort and
preventing light leakage.
Optical Adjustment
After goggle is powered on, you will see an image on the OLED displays. Complete the following
steps to adjust the optics:
1. Focus adjustment: Close one eye and slowly twist the focus knob on that side of the goggle
until the image comes into focus. Once it works well with one eye, repeat the process with
the other eye.
2. IPD adjustment: Close one eye and slide the knob to center the image. Once the image is
centered, repeat the process with the other eye.
3. Fine adjustment: Open both eyes and look at the merged image. Make small adjustments to
the focus and IPD for each eye until it feels visually comfortable and merges into a single
clear picture.
Note: Do not expose the lens directly to sunlight. Otherwise, the OLED displays might be
damaged.
Head Strap
The goggle includes a 50mm (2 inch) wide head strap with battery pocket. Once you have
configured the face plate and padding foam for your preferred face fit, put on the head strap
and adjust the tightness to your preference.
HDMI input
The HDZero goggle includes a single port HDMI 1.4b receiver through a mini HDMI port. The
incoming HDMI video is routed to the OLED display without adding any frame buffer latency.
Please note that most HDMI connectivity issues are due to either incorrect monitor settings or a
faulty HDMI cable. If you encounter issues using the HDMI input, try connecting with
alternative HDMI sources and alternative cables to rule out these common causes.

The current firmware supports resolution up to 1080p60 and 720p100 for HDMI input.
HDMI Output
The HDZero goggle includes a high-performance single channel HDMI transmitter that is fully
compliant with HDMI 1.3a through a mini HDMI port.
The HDMI output will display exactly the same content as what appears on the OLED displays.
TABLE 2. HDMI Output Format

AV input
The HDZero goggle supports AV input through a 3.5mm AV jack. The pinout is shown in FIG 1.
The AV input cable is not included. It is available on the HDZero shop and other online stores.

Expansion Module Bay
The HDZero goggle has an expansion module bay for installing expansion module that supports
analog receiver and/or WIFI modules.
Note:
1. HDZero goggle provides 5V power to analog receiver and in-takes its CVBS output. There are no
control signals from the goggle to analog receiver. You need to tune analog receiver’s channel
and menu setting by its own buttons and display.
2. There are two-row pins on the connector of expansion module, and a two-row socket on goggle.
Make sure these 2-row pins are well seated into the 2-row socket. Analog receiver will not be
able to power up if 2-row pins is one row down.
Expansion Module
Expansion module V1 supports analog receiver only, and V2 supports both analog and WIFI.
Expansion modules are sold separately.
Some of expansion module may have a physical switch to power on
or off the inserted analog receiver. The switch does not control the
power of WIFI circuit of V2 modules.
For batch 2 goggle users, there is a soft switch available in the
goggle menu to turn on the power to module bay. Please
note that early expansion modules cannot be controlled by this soft switch.
The soft switch must be turned on for the module bay to be powered and is off by default.
HT Output
The HDZero goggle has a 6-axis smart inertial measurement unit for head tracking pan+tilt
support. The HT output jack pinout is shown in FIG 2.
The HT cable is not included. It is available on the HDZero shop and other online stores.
Audio Line In/Line Out
The HDZero goggle has a CTIA standard 3.5mm Line in/Line out jack for microphone and
headphones. The pinout is shown in FIG 3.
Mounting Rails
The HDZero goggle has a unique mounting rail for patch antennas or whatever else you might
want to mount.
Here is mount adapter for TrueRC patch antennas by Ryan Quellet, and ball joint rail mount by
userzero1.

FW Port
The FW port is used for flashing firmware to HDZero VTXes. A 150mm programming cable is
included.
The instruction for flashing VTX firmware is described on HDZero Firmware Update section.
Open Source
The HDZero Goggle is open source. You can find the SoC Firmware and Goggle CAD files at
Github

HDZero Goggle Operation
This section describes the general operation of the HDZero goggle.
Controls
– Dial Pad
– Enter Button
– Func Button

Video view and Menu view

Video Source
The HDZero goggle can display video from any of 4 sources:
– Built-in HDZero digital receiver
– AV in
– Expansion Module in (such as with an analog video receiver)
– HDMI in
HDZero Digital Receiver
The “Scan Now” option on the main menu will scan channels R1-R8, E1, F1, F2, and F4 for an
HDZero video signal. It will:
– Lock on to the channel if there is only one valid channel with a signal, or
– Let you choose between the channels if it has found two or more channels, or
– Continue to scan after 5 seconds if no signal is detected, or
– Wait for a long press of the Enter button to exit to the main menu
The HDZero goggle provides the lowest and fixed latency when used with the HDZero Nano 90
camera.
The HDzero digital receiver supports low band, you need to set Source -> HDZero Band to
Lowband if you want to use it.
Note: If Nano90 camera is set to 540p60, please set Source > HDZero BW to Narrow.
Analog Input
The HDZero goggle takes analog video input from either the AV input jack or the external
Expansion Module (not included, available on the HDZero Shop). The goggle processes analog
video from either of these inputs in the same way, but the Expansion Module provides an easy
plug-and-play experience if you are using a standard FPV analog module. For batch 2 goggle
users there is a soft switch available in the goggle menu to turn on the power to the module
bay. This must be turned on for the module bay to be powered and is off by default.
The HDZero goggle uses a novel approach to process the analog input, resulting in improved
analog video quality:
– It uses a video decoder with an adaptive comb filter to separate Y/C from the composite
video;
– It uses a deinterlacer to convert fields to frames, instead of doubling the interlaced
lines;
– It uses an upscaler to record and display the video;

Fan Management
There is one fan on the top of the goggle and one fan on each side of the goggle. All fans are
soft mounted to reduce vibration and noise. There are three temperature sensors on top and
sides of the goggle.
These fans are critical to goggle performance:
– The top fan provides cooling for the OLED displays and defogging for the optical lens;
– The side fans provide cooling for the IO and RF boards inside the goggle
They will prevent goggle from being too hot, improving OLED life span and ensuring maximum
HDZero RF performance.
Top fan can be set to a 1-5, and side fans for 2-9 level, corresponding from minimum to max
speed.
There are two control modes for side fans:
– Automatic mode: Goggle firmware will automatically speed up/down the fan on each
side;
– Manual mode: You can manually set the speed for each fan;
– Regardless of the current mode, the goggle firmware will enter into rescue mode under
these situations:
o temperature sensor on top reports hot: top fan goes to max speed;
o temperature sensor on left/right reports hot: left/right fan goes to max speed;
Note that only the side fans have automatic mode. The top fan is always in manual mode
unless it is in rescue mode.
You can change the top fan speed by pressing and holding the Func Button. You can monitor
the top fan speed changes on the goggle OSD to quickly change the amount of air blowing onto
your face and the optic lenses while in the Video view.
Note: It is recommended to use automatic mode for side fans, and set top fan speed as desired
level.

Image Settings
The HDZero goggle has an image processor to fine tune video before feeding to DVR and display. It
includes:
– Brightness
– Saturation
– Contrast
OLED Control
For OLED display, you may set OLED brightness to the desired level. Note that the OLED brightness
setting applies to the OLED display only.
If the HDZero goggle detects no movement or no key input for programmed time (1/3/5/7 minutes), it
will dim the OLED display as an alarm, and it will wait for another one minute before turning off both the
display and HDZero digital receiver with a short beep. The OLED display and HDZero receiver will resume
normal operation if the goggle detects movement or any key input. This feature can be disabled by
setting the waiting time to “Never”.
OLED displays can provide more vivid colors than traditional LCD panels, However, if they are displaying
the same content for an extended period of time, it may come across issues like “Image retention” or
“Image burn-in”. It is highly recommended to use the above OLED auto off feature or “Go Sleep” from
main menu to turn off OLED while not using the goggle.
DVR
The HDZero goggles integrates a DVR for both the HDZero digital receiver and analog input. These are
the DVR options:
– Automatic Record: DVR will start to record when it detects there is valid HDZero RF on the
current channel, and stops recording when the signal is no longer detected.
– Manual Record: DVR will start/stop only if Func button is clicked.
– MP4 format or TS format: MP4 format is better supported by many video editing applications.
However, MP4 files can be corrupted if the goggle loses power before the file is closed after
recording, which can happen if the goggle runs out of battery or the power cord is unplugged
unexpectedly. Unlike the MP4 format, the TS format saves the stream instantly to DVR without
any risk of corrupted files, even if the goggle suddenly loses power.
– H264/H265. The DVR must use the H264 format when recording 90fps video (it records in
1280x720x90 for better quality). It uses the H265 format in all other cases.
– Audio: You can choose to record audio or not. There are 3 audio sources that can be recorded:
o Built-in microphone
o Line in (From Line in/out Jack)
o AV in (From AV in Jack)

The file system on SD card can be corrupted by suddenly power off while goggle is writing data to it. The
HDZero goggle runs on Linux, and it does not have a big capacitor that saves power for saving the last
emergency bits. The DVR will not work if SD file system is corrupted. Here are tips on how to avoid
powering off while recording is ongoing:
– Auto record mode: after quad is landed, do one of the following
– Long press “Enter” button to switch to menu mode, then power off the goggle, or
– Power off quad first, and wait for 10 seconds, then power off the goggle
– Manual record mode: Click “Func” button to stop DVR before power off the goggle
– Select “Scan and Fix” if Windows or Mac reports problem when SD card is inserted.
TABLE 3: DVR resolution

Playback
The HDZero goggle can play back DVR recordings.
– The player lists the recent recording first. Use Dial up/down to select a file, and click to play it
– On controller bar, use Dial Up/Down to seek video (5 seconds forward/backward), and click to
play/pause
– Long press the Enter button to exit the controller bar, and long press Enter again to exit the
player.
Note: The player will ignore files that are less than 5MB.
OSD
The goggle supports OSD from flight controller (FC OSD) and OSD of its own status (Goggle OSD). You
may select if both OSD should be recorded with video stream at Record Options sub-menu.
Goggle OSD can be shown/ hidden by clicking the Enter button under Video view. The positions of
Goggle OSD items are fixed on current firmware.
The goggle has built-in OSD fonts for BetaFlight, Arduino and iNav. It will automatically load the
corresponding font according to type of flight controller that is connected with HDZero video transmitter. You can also customize FC OSD by putting bitmap files under SD card root
directory/resource/OSD/FC.
Tune Channel
By Dialing up/down, video channel number can be tuned on video mode for HDZero receiver input.
However, this can be disabled by putting a file named as “no_dial.txt” on SD card root directory when
booting up.
WiFi Module
The HDZero goggle supports WIFI video streaming to smart phone, desktop or laptop, if expansion
module V2 is installed. Multiple devices can wirelessly connect to the goggle and receive the video
simultaneously.
Control over the behavior of the V2 WiFi Module is completely managed from within the WiFi Module
page. Users have the ability to configure the goggle as a Host (Access Point) or a Client (Join Network).
WiFi Module page supports both “Basic” and “Advanced” configuration fields.
Basic Fields:
• Enable – Powers On or Off the WiFi Module hardware.
• Mode – Host (Access Point) or Client (Join Network).
• SSID – User can specify a Host and Client network names individually based on Mode.
• Password – User can specify a Host and Client network password individually based on Mode.
◦ Note that password requires a minimum of 8 characters.
• Apply Settings – Stores and configures the WiFi Module hardware with the settings the user has
modified.

Advanced Fields:
• DHCP – This setting only applies to Client Mode.
◦ Note the Address specified will be requested for use by the WiFi. Ultimately it is up to the
router to find and available address if the address requested is not in use, then the one
specified will be used.
• Address – The network ip address.
◦ This setting applies for both Host and Client modes.
• Netmask – The network subnet mask.
◦ This setting applies for both Host and Client modes.
• Gateway – The network gateway ip address.
◦ This setting applies for both Host and Client modes.
• DNS – the Domain Network Service ip address.
• RF Channel – This setting only applies to Host Mode and a user can specify which radio
frequency channel they want to communicate on.

System Fields:
• Root PW – Update the root password for the goggles.
◦ This applies to SSH and SCP communications.
• SSH – Enable/Disable Access to the goggles.
◦ Defaults to disabled as a security precaution.

Finally, if either page is modified “Basic” or “Advanced”, the user must return back to the “Basic” page
and select “Apply Settings” in order to configure the WiFi Module.
In order to establish a wireless video stream with the HDZero Goggles via a smartphone or computer,
the user must follow these steps:
1. The “Basic” page within the WiFi Module page will contain the necessary information in order to
establish communications with the HDZero Goggles:
a. Host Mode – Refer to the SSID and Password fields in order to join the HDZero Goggle
wireless network.
b. Client Mode – Refer to your wireless access point user manual.
2. Install VLC app (or other similar app that supports RTSP) on your device.
3. Open the above app, choose “Open Network Stream”, and type the RTSP URL provided by the
“Basic” page footnote as it will provided the necessary URL in order to establish a video stream via
VLC app, below is the default ip address if the user has not made modifications within the
“Advanced” page:
rtsp://192.168.2.122:8554/hdzero
Video latency is expected due to networking protocols, buffering schema of the app, and OS platforms.
Clock
The HDZero Goggle includes a Real Time Clock (RTC) but due to shipping restrictions a battery was not
preinstalled. Not having the battery will result in the loss of date and time. However, the RTC can still
be configured via the Clock Page which will set the system clock and hardware clock upon invoking “Set
Clock”. For users who have installed an aftermarket battery this only needs to be done once. Otherwise,
when the goggles boots up it will revert to the last date and time the user had specified since applying
“Set Clock” command.

An aftermarket battery could be CR2032 laptop battery with MX1.25-2P male connector. An example
can be found here.
Note that it is user’s full responsibility for any damage due to opening the goggle to install the battery

HDZero Firmware Update
Download the latest firmware HDZEROGOGGLE_Revyyyymmdd.zip from HDZero download site. Then
unzip it.
TABLE 4. Firmware File

Flashing Firmware to a HDZero VTX
The HDZero goggle can flash firmware to a HDZero video transmitter via its FW port. Here are the steps:
To flash a single VTX:
1. Copy HDZERO_TX.bin to root directory of a SD card that is formatted as FAT32
2. Power on the goggle
3. Connect the VTX and HDZero goggle with the included programming cable
4. Go to Main menu | About | Flash VTX, the display will show the status of the flashing process
5. Disconnect the VTX
6. This VTX is now flashed with the latest firmware
To flash multiple VTXes of the same type:
1. Copy HDZERO_TX.bin to root directory of a SD card that is formatted as FAT32
2. Power on the goggle
3. Connect one VTX to the HDZero goggle with the included programming cable
4. Go to Main menu | About | Flash VTX, the display will show the status,
5. Disconnect the VTX, this VTX is flashed
6. Repeat 3-5 for the other VTXes
Note: HDZERO_TX.bin will not be removed from SD card after programming so that you can flash
multiple quads without copying file to SD card.
Flashing Firmware to the Goggle
The HDZero runs on Linux. Its firmware contains the customized Linux distribution and its application
software. We only need to update the application instead of updating the whole OS and application in
most cases. However, there are some rare cases where the OS could become corrupted, such as losing
power during update process. It is also possible that changes may have to be made to the OS in the
future to add new functionality.

Before you start to update firmware, go to Main menu|Firmware|Current version. It should be in the
following format:
– n.xx.yyy, or
– app:n-xx rx yy va zzz
If n is greater or equal than 9, take Normal Goggle Firmware Update Process, otherwise take A Special
One Time Goggle Firmware Update Process.
Normal Goggle Firmware Update Process (for n≥ 9)
1. Disconnect all cables from the goggle. Keep the power cable only;
2. Copy HDZERO_GOGGLE_nnn.bin to root directory of a SD card that is formatted as FAT32, and
make sure there is no previous firmware in the root directory;
3. Power on the goggle;
4. Go to Main menu | Firmware | Update Goggle, the display will show the current version;
5. Wait for the completion (about 3 minutes), then power off;
6. Done!
A Special One Time Goggle Firmware Update Process (for n < 9)
1. Disconnect all cables from the goggle. Keep the power cable only;
2. Extract HDZERO_GOGGLE- nnn.bin/HDZG_BOOT.bin/HDZG_OS.bin, and copy them to root
directory of a FAT32 formatted SD card;
3. Insert SD card, Select Main menu | Firmware | Update Goggle. Power off after completion;
4. Power on goggle, wait for 1 min then power off;
5. Power on goggle, wait for 4 mins then power off;
6. Done!
Note: HDZG_BOOT.bin/HDZG_OS.bin will be removed from SD card if update successfully.
The goggle can be bricked under some rare cases. If the goggle is on the firmware version n is 9 or later
before bricked, follow Goggle Emergency Firmware Update Process; if n is earlier than version 9 or you
are not sure which version it was on, please follow Goggle Emergency Firmware Update Process using
Phoeix App.
Goggle Emergency Firmware Update Process (for n≥ 9)
1. Disconnect all cables from the goggle. Keep the power cable only;
2. Extract HDZG_OS.bin/ HDZGOGGLE_RX.BIN/ HDZGOGGLE_VA.BIN, and copy them to root
directory of a FAT32 formatted SD card, and insert SD card to the goggle;
3. Power on goggle, wait for 5 min then power off;
4. Done!
Note: HDZG_OS.bin/ HDZGOGGLE_RX.BIN/HDZGOGGLE_VA.BIN will be removed from SD card if update
successfull.

Goggle Emergency Firmware Update Process using Phoenix App (for all versions)
Download PhoenixCard.zip from the HDZero Download site, and extract it to a location on a Windows
machine, for example, C:\PhoenixCard. This is a one-time process. There is no Mac or Linux version for
now.
Download the latest firmware package from the HDZero Download site, and extract all files in
HDZEROGOGGLE_Revyyyymmdd to your local drive, i.e. C:\Temp.
1. Launch C:\PhoenixCard\PhoenixCard.exe;
2. Follow the steps on FIG.5 to make a bootable SD card;
3. Eject the SD card from Windows, and insert the SD card into the SD card slot of the goggle;
Unplug all of the cables, i.e., HDMI in/out, Line in/out, AV in. Keep the power cable only. Power on the
goggle, you will hear a long beep immediately. Wait for 3 minutes and you will hear another long beep;
4. Power off the goggle, and pull out the SD card from the goggle. (Do not power on goggle now);
5. Follow the FIG.6 to restore the SD Card from BOOT mode, and format it as FAT32 on Windows;
6. Copy HDZGOGGLE_RX.bin and HDZGOGGLE_VA.bin to the SD card root
directory;
7. Insert SD card into goggle, power on the goggle, wait for 2 minutes, and
there will be a long beep;
8. (Optional) Pull out the SD card, and check SD card contents on the PC.
The 2 files should be removed if flash process is successful;
9. Power the goggle off and then on again.

Note. A bootable SD card has a hidden partition that Windows Explorer will not show. And it can’t be
removed even SD card is formatted with Windows Explorer. It means the goggle will flash itself from the
bootable SD card unexpectedly and mess up goggle firmware if a bootable SD card is inserted when the
goggle is powered on.
Step (6) must be followed strictly to get rid of the hidden bootable partition. Otherwise, it will brick the
goggle when goggle is powered with this SD card inserted. If this happens, you will need to repeat the
emergency firmware update process described in this section.

Troubleshooting
Support should be attempted in the following manner.
1. Read this manual first
2. Follow us on Facebook/Discord if possible
a. Facebook: https://www.facebook.com/groups/hdzero
b. Discord Server: https://discord.gg/VSkXzkKPHt
3. Email Technical Support: support@divimath.com

Warranty
The HDZero Goggle can be exchanged for a new unit within 7 days for any manufacturing defects if
returned in new condition. The optic module will be warrantied for repair for 6 months, and all other
components, for 2 years, if there are no signs of excessive use. Buyer will be responsible for shipping
costs. If beyond the warranty period, we will provide repair services for a cost. For assistance with
warranty issues, please contact support@divimath.com.