Practical LiDAR for Hobbyist Roboticists

Scott’s slide deck: slide deck (PDF)

Followers of DPRG’s competitions are familiar with Scott Gibson’s very successful robot CanMan. CanMan utilizes a spinning LiDAR manufactured  by RPLidar (~$100). In competitions where the arena is bounded by walls, CanMan’s LiDAR allows the robot to reacquire its location even after a collusion with walls or other robots.

At the October 12th DPRG monthly meeting Scott is going to share how you can add a similar LiDAR to your robot. The presentation will take a quick look at the serial interface and data fields used by the RPLidar unit, and then dive deep into how to use this data.

Scott will discuss the algorithms and code that he uses to:

  • Find the center of the arena,
  • Align to an arena wall,
  • Detect an outside edge,
  • Detect an inside edge.

This is a great opportunity to learn about how to use a spinning LiDAR unit.

The meeting is at the Dallas Maker Space and starts at Noon on Saturday, October 12th.

Introduction to the ESP8266 – Monthly Meeting Topic – Sep 14th, 2019

Steve’s code and presentation slide deck: code_and_slide_deck

DPRG member Steve Edwards will present an Introduction to the ESP8266. The ESP8266 is an easy to use, inexpensive, yet powerful 80 MHz WiFi micro-controller. You will learn how to create a simple and secure REST api (Web Service), which will allow you to send commands or query information from your robots or other electronic projects. Steve will also be demonstrating one of his recent projects. A lot of blinking LEDs are involved.

This is a great opportunity to learn about the ESP8266.

The meeting is at the Dallas Maker Space and starts at Noon on Saturday, September 14th.

Autonomous Rover Robot with GPS RTK and Novel Control System – Monthly Meeting Topic – August 10th, 2019

Ross’s slide deck can be downloaded at: slidedeck (PDF)

Guest speaker Ross Melbourne will demonstrate his autonomous rover robot which uses GPS RTK for navigation, and a novel robot control system that employs Unity and Python. Ross’s robot control system has potential practical applications such as: robotic lawn care, security patrol robots, and autonomous delivery services. Ross’s talk will cover both the challenges and the lessons learned that he experienced while building the robot.

This is a great opportunity to see a sophisticated antonomous rover build.

The meeting is at the Dallas Maker Space and starts at Noon on Saturday, August 10th.


Untangling the Mesh: Bluetooth, BLE, Zigbee, Wi-Fi, LoRa, DigiMesh, Z-Wave … – Monthly Meeting Topic – June 8th, 2019

Brent’s slide deck: slide_deck (PDF)


The multitude of radio communication protocols available to the hobbyist roboticist can be overwhelming. At the June 9th monthly meeting presentation “Untangling the Mesh: how to choose between Bluetooth, BLE, Zigbee, Wi-Fi, LoRa, DigiMesh, Z-Wave, …”, guest speaker Brent Grimm will compare and contrast BLE to other wireless protocols.

This is a great opportunity to introduce yourself to the various trade-offs between wireless communication methods and how they can be used control or share data with your robot.

Note: Ron Grant shared a very interesting show and tell of his Challenge line following course simulator. See the video above.

The meeting is at the Dallas Maker Space and starts at Noon on Saturday, June 8th.

Line Following Kinematics & Open source course programs in Processing – Monthly Meeting Topic – April 13th, 2019

Will’s slide deck: slide deck (pdf)

Github for Ron’s LF Course Generator: LF Generator

DPRG’s April monthly meeting topic is “Line Following Kinematics & Open source course programs in Processing”. DPRG Members Will Kuhnle and Ron Grant will share their experiences on Line Following Kinematics and Processing based Line Following course simulation.  The meeting is at the Dallas Maker Space and starts at Noon on Saturday, April 13th.

Agenda:

Part 1 – Line Following Kinematics:
Will Kuhnle will address questions like:

  • What are Kinematics of line following?
  • How can Kinematics help my robot design?

This part of the presentation is about how to make a robot follow a path based on its physical parameters and design.  It will look into the problems of following  a smooth curve path (e.g. the DPRG Novice Course), and the more advanced problem of following a combination of smooth curves and disjoint curves (e.g. the DPRG Advanced Line Following Course).

Part 2 – Open Source Course Builder and Interpreter programs:
Ron Grant will demo and explain his interactive line following course builder program, which is written with Processing (java environment). This builder program reads/writes a human readable format and can use SVG files created in such programs as Inkscape or Adobe Illustrator. Note: DPRG stores past courses in their GitHub repository in SVG format.

Ron will also share a few words on a data format and interpreter that reads a description of line following course tiles in order and tracks path with each sequential tile. The format supports DPRG line following courses including all features of the Challenge Course except the finish gate (which is “hand coded”).

Both programs will be published to a DPRG’s GitHub repository.

Show and Tell:
After the presentations, anyone who wants to show or demo a project that they are working on is welcome to present it to the group.

About DPRG Monthly Meetings:
DPRG hosts interesting presentations each month during its regular membership meeting. These meetings and presentations are open to public and free to attend. We hope to see you there. Everyone is welcome.

About DPRG:
Dallas Personal Robotics Group has been actively building robots for fun since 1984. We meet every Tuesday evening and every 2nd Saturday of the month. DPRG also frequently participates in community events. We usually meet at the Dallas MakerSpace. Guests of all ages and skill levels are always welcome! It is a great place to meet others exploring the world of hobby robotics, and share tips and experiences.

Using an Android Phone with Your Robot – Monthly Meeting Topic – March 9th, 2019

For tomorrow’s meeting Iron Reign will share information about how they use Android phones to run their robots. The presentation will be informal and off-the-cuff. It will discuss improvements to their competition robot since last presentation, but the emphasis will be a coding walk-through using the Android framework provided by FIRST – the STEM program in charge of their competition.
The walk-through will show some simplified examples. If you want to follow along on your own computers, you can install the tools and starter code below:
1. Download Android Studio – this is a free development environment based on jetbrains, the java sdks will come along for the ride
2. Download the ftc_app starter framework from github – this is starter codebase
3. Compile the app. This needs to be done ahead of time because it will fail multiple times as it figures out new dependencies that need to be downloaded.
There is a fair amount of downloading in all of those steps. We won’t have time to debug the install process for those trying it on their own. However, if you are able to follow along live, we might have a way for you to test a very basic teleop program.  Iron Reign plans to bring some robot phones and show how to debug wirelessly. If it doesn’t work for you, don’t worry about it – if folks are interested we can follow up at RBNO.

After the presentation there will be a show and tell, with a Donkey Car demo.
The meeting is at the Dallas Maker Space and starts at Noon on Saturday, March 9th. 

Useful OpenCV Routines for Hobby Roboticists – Monthly Meeting Topic – February 9th, 2019


DPRG’s February monthly meeting topic is “Useful OpenCV Routines for Hobby Roboticists”. Member Ray Casler will share his experiences using OpenCV on his robots .

His presentation will cover:

  • blob detection
  • LiDAR – IR filter and line laser
  • pixel diddling – Challenge line following strategy
  • using distance maps from Xbox Kinect sensors
  • object tracking

Many people interested in Donkey Car have started their builds. There will be a Donkey Car show and tell after Ray’s presentation. Bring your Donkey Car build and share your experiences.

The meeting is at the Dallas Maker Space and starts at Noon on Saturday, February 9th. 

DPRG Elections – 2019

DPRG 2019 Annual Meeting Minutes: Annual Meeting Minutes – 2019

Once again it is time to hold elections for DPRG club officers. The election will occur at the DPRG monthly meeting on January 12th, 2019. It is very important that members vote. The by-laws require that a specific percentage of members vote to make the election official.

A slate of candidates composed of the present officers is proposed for reelection in the 2019 election. The club’s by-laws limit the terms of the President and Vice-President to two years. This would be the 2nd term for Ray and Carl. This slate is composed of members who have indicated interest at recent club events. Any member can come forward and be added to the list of people considered for the various officer’s positions. If you want to explore holding office, an overview of officer duties can be found at  officer duties. You can also get additional information by talking to an existing officer at any monthly meeting or RBNO. If you want to throw your hat into the ring, please let me know quickly at email “secretary at dprg dot org” so you can be added to the ballot.

Proposed Slate of Officers for 2019

President: Ray Casler
Vice-President: Carl Ott
Treasurer: Steve Edwards
Secretary: Doug Paradis
Librarian: John Kuhlenschmidt

How to Vote

All members in good standing can vote. The list of members is at member list. If you are not on the list and you think you should be, the problem is most likely that you need to renew your membership. Contact “secretary at dprg dot org” if you need help renewing your membership.

Members can vote by emailing their vote to “election at dprg dot org” before the January 12th meeting. The email should contain the text “I vote for the proposed officer slate”, or “I vote for the following people for office”, or similar text that allows our volunteer election vote counter to determine your intentions.

Members can also vote in person or proxy at the January 12th DPRG meeting. If voting by proxy, you should signal your intention to vote by proxy by sending an email to the person that you are giving control of your vote and to “election at dprg dot org” so the person holding your proxy and the person tallying votes knows of your intention. The person holding the proxy must then vote.

Iron Reign’s Regional Championship Robot, and Clay and Ray Talk Line Following Strategy – Monthly Meeting Topics – Dec. 8th 2018


At the December monthly meeting, DPRG has the honor to host 2 interesting presentations.

In the first presentation, Iron Reign will show and discuss their robot, Rover Ruckus. Rover Ruckus is a competitor in the upcoming FIRST robotics regional championship. The robot is controlled by an Android phone. It also utilizes openCV for computer vision, and TensorFlow for machine learning.

Next, members Clay Timmons and Ray Casler will present the strategy and code their robots are using in their effort to successfully complete the challenge line follow course. They plan to cover the basics of line following all the way through the difficulties on the challenge course Their robots use Raspberry Pi for control and openCV for computer vision.

Lastly, the DPRG board will present a slate of candidates for the upcoming annual officer election, which will end at the January Annual meeting. If you are a member and wish to seek an officer position, please contact one of the current officers.

The meeting is at the Dallas Maker Space and starts at Noon on Saturday, December 8th. ROOM CHANGE – This month the meeting will be in the Purple classroom instead of the Interactive classroom.

Intro to Fuzzy Logic – Monthly Meeting Topic – July 14th, 2018

Doug’s slide deck can be found at: slide deck (PDF)

DPRG’s monthly meeting for July is on Saturday, the 14th, at the Dallas Maker Space. The meeting starts at Noon.

Pursuing Artificial Intelligence, scientists and mathematicians have searched for ways to allow computers to handle vague ideas. Lotfi A. Zedeh realizing that conventional computer logic could not manipulate information presented in subjective terms, such as, “slightly, a little more, way more” laid out the mathematical basis for a method called “Fuzzy Logic“. Fuzzy Logic has since found use in the design of controllers of all kinds.

DPRG’s topic of the month is “Intro to Fuzzy Logic”, presented by member Doug Paradis. Doug will cover the steps used to build a Fuzzy Logic controller. As a demonstration, he will implement a Line Following Fuzzy Logic controller on the inexpensive Arduino “smart car” style robot previously used in the “Build More Robots!” tutorial series.