Xaxxon

Now that Flash is Really Dead, Oculus Prime Software Update

Sat, 06 Mar 2021 15:56:34 +0000

Previously, Xaxxon Oculus Prime robots running Oculusprime Java required a web browser with the Flash plugin for remote control. Now that Adobe Flash is really no longer an option in the latest web browsers, remote control of the robot had become pretty much impossible (unless you’re running an old browser).

The latest software update uses webrtc tech for streaming video and audio, instead of Flash. Unfortunately, the previous OS that shipped with Oculus Prime robots, Xubuntu 16.04, doesn’t support webrtc (at least not the way we’re implementing it) — so a full system wipe and manual OS upgrade and software install is required.

Full install instructions are here:
www.xaxxon.com/documentation/view/oculus-prime-software-install

Aside from fixing video streaming, the update offers lots of minor under-the-hood fixes. A more obvious functionality bonus is the new mobile/phone web browser remote control:

This can be accessed by pointing your device’s web browser to the usual remote control URL, and adding '/mobile.html' at the end. For example:

http://192.168.0.111:5080/oculusPrime/mobile.html

If any questions or bug-fix suggestions, please contact us

Xaxxon OpenLIDAR Interview/Article, Firmware Update, and Accessory Version

Wed, 20 Nov 2019 13:16:55 +0000

The new Xaxxon OpenLIDAR sensor was mentioned a few times on robotics blogs recently (including adafruit and hackster), and there’s a thorough write up/interview on the 3D location technology website Spar3D.

The Spar3D article mentions the Oculus Prime accessory version, and here is a photo of what is hopefully the final version of that, installed:

This will be available soon; we’re still ironing out the software update that goes along with it. It drops the use of the depth camera for making maps and instead uses the lidar only (much faster and easier!). For auto-navigating, it simultaneously uses the lidar for localization, and the depth camera for detecting obstacles that are lower or higher than the lidar’s horizontal scanning plane (ie., otherwise invisible to the lidar).

OpenLIDAR Firmware Update

The firmware has had a few updates and is now at version 1.185. The code now uses a version of the Arduino I2C Wire library that allows a timeout parameter. Previously, if the Garmin LIDAR-Litev3 sensor failed to respond to a single I2C read/write request, it would cause the entire microcontroller to lock up, throwing a fatal ROS error and requiring a reset of PCB. There are six I2C read/write requests per sensor reading, so at 715Hz that’s 4290 per second… that’s lots of I2C requests to go wrong! The sensor and the stepper motor are running off the same power supply, so motor noise is likely one of the causes of rare I2C errors (even though the board design isolates the two as much as possible).

Now, instead of locking up, the I2C function will timeout after 1ms and the sensor will try the distance reading again.

You can see what version firmware the sensor has by running the ROS node with:

    rosrun xaxxon_openlidar lidarbroadcast.py

The version will be output to the ROS log when the sensor connects. Alternatively, you can use the Arduino IDE terminal and enter the command 'y' to get the version.

To get the latest firmware, go into your xaxxon_openlidar Arduino sketch folder and do a 'git pull'
(or git clone from https://github.com/xaxxontech/xaxxon_openlidar_pcb.git if you don’t already have it).
Then upload to the board using the Arduino IDE.

First Look at the Xaxxon Open Lidar Project

Mon, 29 Apr 2019 10:00:31 +0000

Here’s a couple pics and a short video of our latest product: the Xaxxon Open Lidar sensor! It’s a USB powered rotational laser scanner with open software and hardware, intended for use with mobile robots and simultaneous-location-and-mapping (SLAM) applications.

The sensor has a simple mechanical design, using the proven Garmin LIDAR-Litev3 laser distance measurement sensor, wired through a rotational slip ring, with stepper motor drive, two 3D printed frame parts, and an Arduino compatible PCB. Power and communication are delivered via USB cable.

Initial ROS drivers are up on Github, with dynamically configurable settings including:
-RPM (10-250, 180 default)
-Sample rate (up to 750Hz)
-Range limits (up to 40 meters, even in sunlight!)

We’re working on adding this unit to our online shop now, with all the details, circuit schematics, and printed part STL downloads. It will be available as a fully assembled and tested sensor, and a 3D-print-your-own kit.

Of course, there is also an Oculus Prime accessory version in the works!

New for 2019 - the Xaxxon POWER v2 PCB

Sun, 20 Jan 2019 14:14:11 +0000

The first of a few NEW Xaxxon products for 2019 is the POWER v2 PCB!

This battery charging and system power management board adds new features to the 1st generation Xaxxon Power LiPo3S PCB, and fixes issues. Enhancements include:

No parasitic battery drain (ie., you no longer need to be careful about unplugging batteries when not using the system, which should lead to fewer premature pack deaths!)
Optional daisy-chaining of multiple boards and batteries for increased capacity
Second soft power shutoff mode added: you can now kill system power only, yet keep the 5V microcontroller alive (drawing very little power), and optionally bring system power back up after specified delay
Optional isolated battery-only power out (eg., for 12V motors to never experience high wall power voltages)
Higher wall power voltages accepted, up to 20V
Protection diode and 5A fuse now on-board, simplifying wiring

Board Dimensions/Example Setup/Typical Wiring Diagram:

All new Xaxxon robots will be shipped with this board pre-installed, along with an Oculusprime software update that makes use of the second soft-power shutoff mode, to add a ‘drownproofing’ feature:
For lost robots that are unable to dock, with no remote help immediately available – instead of the usual powering down completely when the battery is depleted, the PCB will optionally power down the host system only, while leaving its microcontroller alive, then it will bring the host system back up every hour on the hour for 5 minutes, to see if any remote help is available.

The board is AVAILABLE NOW for purchase from our web store, for general mobile robotics projects, and DIY mobile PC projects. The previous generation board is still available (on sale!) while supplies last.

Bonus for current Xaxxon robot owners: if you want to upgrade to this new board you’re eligible for a discount! If interested, please contact us

Updated MALG PCB version 3

Mon, 15 Oct 2018 14:13:36 +0000

We’ve once again updated our multi function differential drive robot MALG PCB — it retains the same basic functionality with slightly improved microcontroller power decoupling/smoothing, and a few layout changes.

Gone is the ancient 4 pin Molex jack found in the previous MALG — apparently the original Molex ‘Mate-N-Lok’ style dates back to 1963! The Molex cable was being used simply as a way to get 5V power from a motherboard, and to not be limited by the 500mA maximum supplied through the USB cable. Instead, with the J4205-ITX and J5005-ITX motherboards supplied with Oculus Prime SLAM Navigator robots, we’re now running a single lead from the motherboards’ +5V pin found in its chassis speaker header.

For flexibility we’re staying with use of Pololu daughter boards for the gyro. As well there is now an alternate gyro header for optional use of latest generation Pololu gyros and IMUs.
The photo below is of a heavily modified SLAM Navigator sporting a second MALGv3, equipped with a 9-DOF Pololu AltIMU-10:

It’s running our modified version of the Razor_IMU_9dof ROS package with Attitude Heading Reporting System (AHRS) firmware.

Other changes are:

Audio jack placement no longer interferes with the USB cable
Changed to the more common micro-B USB jack
Omit unused ‘FWD FLD’ LED circuit
Location change to one mounting hole

For more details and to buy the MALGv3 PCB, with or without gyro daughter board, go to the MALGv3 product page.

MALG PCB Back In Stock with New Gyro

Tue, 21 Nov 2017 10:35:37 +0000

The MALG (Motors-Audio-Lights-Gyro) multi function, Arduino compatible, differential drive robot PCB is back in stock!

Our remaining old MALGs had quality issues with their MAX21000 gyro ICs. So, otherwise perfectly good boards have been resurrected, with Pololu daughter boards sporting the L3GD20 three-axis angular rate sensor.

Performance-wise it seems there is no significant difference between the two gyros: by the specs the newer L3GD20 sensor has the edge, but they both ultimately provide super-accurate rotational odometry when used in mapping and auto-navigation. (The MALG PCB is standard equipment in our Oculus Prime mobile robots).

Expansion header pins that are occupied by the daughter board are still available via pass-thru pads on the underlying interface board, as detailed in the connection diagram:

(click to enlarge)

More information on the MALG PCB (revB), including schematic and datasheet is available here. Firmware source code can be found in the github repo.

Oculus Prime Software Updated with 4G/LTE Connectivity

Tue, 25 Oct 2016 11:53:49 +0000

Development and testing is now complete for the Relay Server software addition, which allows remote operation of Oculus Prime mobile robots connected to the internet via mobile 3G/4G/LTE networks. It also allows operation behind NAT firewalls, or on any network where there is no ability to configure and forward ports necessary for general internet remote access.

All that is required is to run an instance of the Oculusprime Server application on a device connected to an unconstrained network. This will act as the ‘relay’ server, which you then configure the robot to connect to. When you want to remotely connect to the robot, you connect to the relay server instead, which relays commands and video from the robot seamlessly. The server can be running on any Linux system, including a Raspberry Pi, or within a virtual Linux environment on a Windows or OS X PC.

Now you can equip Oculus Prime SLAM Navigator or Pi Explorer with a smartphone or mobile wifi hotspot, and see how far you get driving around outside, free from the limited range of a wifi network (in fair weather, of course!)

This addition to the Oculusprime Server application has been on the to-do list for a long time, but has been put off because, well, it required a lot of boring network programming. (There always seemed to be something more exciting to work on, like testing out the newly-opened-sourced Google Cartographer ROS package.)

Summary of enhancements to Oculusprime Server version 0.8:

Relay server
Expanded network menu
Wifi Access Point Manager upgraded to version 0.914
Red5 streaming media server upgraded to version 1.07
Apache Tomcat web server upgraded to version 8.0.33
Updated power PCB firmware (auto power-off at 30%, reduce false positive errors)
Force disable navigation before auto-dock
Added calibraterotation command
Added no-battery-connected indicator to web browser UI
Minor bug fixes, optimisations

For software update instructions, see here.
For more details on running the relay server, see here.
Java 8 is now recommended, which has to be installed manually, see here for upgrade instructions.

Video: SLAM Navigator Autonomous Driving in Warehouse at Night

Fri, 30 Sep 2016 09:08:31 +0000

Watch an Oculus Prime SLAM Navigator unit drive itself around a warehouse at night:

The video shows the view through the remote web browser interface – the only user interaction is 3 clicks, selecting 2 waypoints then return to charging dock.

At around the 2:15 mark you can watch it close in and dock with its charging dock, which is tightly placed in a narrow slot between racks.

The map was created in one attempt by manually driving around the warehouse for 10 minutes, and was used in its original (un-edited) state.

Thanks to Shodor Industries for the video!

An Exploration of Stereo Vision SLAM Mapping - Early Prototype

Thu, 23 Jun 2016 09:34:03 +0000

Not too long ago, the availability of low cost depth sensors, suitable for mobile robot auto-navigation and SLAM mapping, had become a problem. Apple bought Primesense, and along with it the intellectual property behind the original Microsoft Kinect and Asus Xtion sensors. The excellent Asus Xtion RGBD camera, which was to be the main SLAM sensor for Oculus Prime, was discontinued. The Kinect 1 was still available in quantity, but it was bigger and heavier, and required separate 12V and 5V power.

And it somehow just looks wrong with a Kinect mounted to Oculus Prime:

So, we decided to explore using stereo vision as a possible option. A prototype robot was conjured, sporting two Lifecam Cinema cameras:

OpenCV’s Semi-Global-Block-Matching (SGBM) algorithm yielded decent looking depth data from combined images. Below left is the left camera view, and on the right is the disparity image generated with the cameras separated by a 60mm baseline – pixel intensity is proportional to distance from camera:

Comparing the depth images from the stereo setup vs the Asus Xtion camera was looking promising (stereo image on top, Xtion image on bottom, left camera 2D image inset):

In practice however, with this stereo setup as the data source for ROS SLAM mapping, there were issues. The depth data was quite noisy for some surface textures, and depth accuracy wasn’t very good beyond a few meters. Also, the SGBM algorithm tends to cause data omission for large texture-less surfaces.

The image below shows a comparison of a plan view map of the same area, generated using the stereo setup on the left, and using the Asus Xtion depth camera on the right (using data from the horizontal plane only, and pure odometry to align the scans):

Stereo map on left, Xtion on right (click to enlarge)

The stereo scan noise occasionally projected a small false obstacle, that would wreak havoc with the ROS path-planner, and the inaccuracy or omission of distant features would cause weak localisation (and a lost robot).

Another problem was the slow speed of the system: the OpenCV Java SGBM processing, along with all the other robot functions fighting for CPU time, would only yield 2 frames per second (the prototype stereo-bot had an Atom N2800 CPU), demanding that navigating robot speed be slowed way down, to reduce errors.

In retrospect, an integrated stereo solution like the Zed camera, with some on-board processing and tightly-calibrated cameras, would have been much more effective (if money was no object).

In the end, we stuck with the Asus Xtion, dwinding supply and all, in the hope that the near future would deliver a new low cost depth sensor with stable supply.
Luckily the Orbbec Astra came along just in time.

Oculus Prime Software Updated With Follower Mode and Video Recording

Mon, 13 Jun 2016 09:41:41 +0000

Since the last 0.709 release, the Oculusprime Server Java application has been updated to 0.713 with the following enhancements:

On-board video recording
Follower function added (for SLAM Navigator version)
Auto-docking minor reliability improvements
Added reverse arc moves
ARM-supported avconv video streaming added 720p photos, sound detection, and stability improvements
High current drain detection disables motion until resumed by forward command
Power PCB firmware less strict checking on minor warnings

Video Recording

Video recording on/off toggle button has been added to the main menu:

Videos are saved under 'oculusPrime/webapps/oculusPrime/streams' with the current date/time as the file name, in FLV format.

Optional – Converting Video Format

If you want to convert to another format after recording, an easy way is to use avconv. If you’re running the Raspberry Pi equipped Oculus Prime Explorer version, it’s already installed. For SLAM Navigator versions, it can be installed by opening a robot terminal session and entering:

$ sudo apt-get update
$ sudo apt-get install libav-tools

To convert the file to the MKV format, change to the streams folder and enter the avconv command (replace [filename] with the right filename):

$ cd ~/oculusPrime/webapps/oculusPrime/streams/
$ avconv -i [filename].flv -codec copy [filename].mkv

Video Recording as Navigation Route Waypoint Action

For SLAM Navigator Versions, you can now record videos at route waypoints. ‘Record Video’ has been added to the list of waypoint actions:

It will record for the same time as the ‘Stay here for’ waypoint duration, and download links to videos will be posted to the navigation log.

Follower Mode

Follower mode on/off has been added to the navigation menu:

This will enable Oculus Prime, equipped with a depth-camera, to autonomously start following any object that comes within a meter or so in front of it.

The new ROS follower node, added to the Oculusprime ROS package, is a port of the Turtlebot Follower node, with code modified so it works with Oculusprime’s skid steering.

Follower mode can also be launched the traditional ROS way, from the command line with:

$ roslaunch oculusprime follower.launch

If you auto-update Oculus Prime from the server menu, it should grab the latest ROS code and compile automatically. Compiling is required for this node, since it’s coded in C++ instead of Python. If you’re having any problems, try compiling again with:

$ roscd
$ cd ../
$ catkin_make