[Dprglist] Recommendations for Robot Platform

[Carl Ott]

Hi Murray,

Welcome to the DPRG mailing list - Thanks for reaching out - Hello New
Zealand!

No kidding about doing an 8085 based computer in 1979 as a high school
student - that puts you pretty close the great Woz of Cupertino :)

Wow what a great list of options - lots of new bits and pieces... Much
appreciated.

No worries about the BOM prices and leaning on ready-made components. I am
on a quest for kits that we might base a training series on. But it's
always great to look at projects like the one you're starting on.

You mentioned servo mounting a LiDAR - some DPRG members have done that.
Some have also dabbled with the constant rotation LiDAR - speak up if you'd
like chat about those - they'll give you lots more data than you could get
with a servo mounted LiDAR.

Glad to hear you've had good success or at least positive impressions from
the Pimoroni modules.
I've recently purchased some Pimoroni OnOff Power Shims to get my Pi
projects off to a robust start, and hopefully avoid corrupting the file
system with unceremonious power yanks. Have you tried those? I'm about
ready to install the first one and check it out...

I've also noticed the OSEPP kits - so it will be nice to hear about your
experience with those.  Would it take much encouragement to have you blog
about your project as it comes along? We have had some interest
time-to-time in the club about using Bluetooth and other RF mechanisms for
indoor location mapping.  And we're aware of some systems out there to
facilitate that - for example this one which appears geared for public
venues - https://quuppa.com/ (not sure that it's hobbyist friendly).

We do need to up our game on the DPRG project blogging front - we've been
active but haven't published much about our projects except for
competitions and our monthly presentations.

In terms of typical DPRG projects, it could help to look at our recent
contests
- 2020 Fall RoboRama draft plans, https://www.dprg.org/roborama-2020/
- Full menu of contests we tend to pick from
https://github.com/dprg/Contests

and our YouTube channel which you've probably already found:
https://www.youtube.com/user/DPRGclips

Lots of members do side projects unrelated to the DPRG contests. But the
contests do a decent job of showing the kinds of robots most people take on.

Again - Welcome!

Carl














On Tue, Nov 19, 2019 at 1:16 AM Murray Altheim via DPRGlist <
dprglist at lists.dprg.org> wrote:

> Carl Ott <carl.ott.jr at gmail.com> wrote:
> > Hi All,
> >
> > Can y'all help build a short list of robot learning platforms that
> > are good for coming up to speed with robot platforms? I'm looking
> > for kit options with an emphasis on software - e.g. how to read
> > sensors and write & implement algorithms to drive actuators.
> >
> > *Any recommendations for kits w/in these constraints?*
> >
> > 1. wheels *with encoders*
> >
> > 2. relatively minimal mechatronics effort & tools needed to get started
> >
> > 3. enough sensors or easy / off-the-shelf plug-n-play extensibility for
> > DPRG style contests, e.g.
> > ** line following
> > ** wall following
> > ** quick trip
> > ** 4 square
> [...]
>
> Hi Carl,
>
> Perhaps this is a good time to introduce myself, as I just joined the
> mailing list a few days ago, having recently seen David Anderson's
> autonomous robots demo on YouTube. If David is on this list I'd like to
> thank him: his obvious enthusiasm and pragmatic approach is quite
> inspiring. From links on his site and others I've since been reading up
> on subjects like subsumption architectures, etc., and found this mailing
> list.
>
> Back in 1979 I built a robot using an 8085-based single board computer,
> a couple of large DC motors and a chassis made out of aluminum and some
> circular PC boards found in a surplus shop in Des Moines, Iowa, that
> were apparently from the insides of a missile. It was an ambitious
> project for a high school student and I never quite got the ultrasonic
> sensors working properly, but it was a good learning experience, a lot
> of fun, and led eventually to an IT career.
>
> Over that career I had the fortunate experience of working at NASA
> Headquarters for a few years, where as a fellow Mac enthusiast I met
> David Lavery, the head of the robotics division. At the time he had a
> Mars Sojourner rover sitting on his desk. I remember marvelling at the
> beauty of the machining of the wheels, and wishing I had that kind of
> budget (and a machine shop). While setting up a demo I also had the
> opportunity to pilot a telerobotics sled under the ice in Antarctica.
>
> Years have passed and I now live in New Zealand, where most of my
> creative energy has over the past few years been in music (I have an
> improvisational abstract band named Barkhausen; we just finished our
> second CD).
>
> The combination of experimenting with some DIY microcontroller-based
> Eurorack synthesizer modules and the advances in the world of Raspberry
> Pi has found me back into robotics. For the past few months I've been
> purchasing various playthings from Pimoroni and Adafruit and doing
> some experimenting.
>
> And planning...
>
> I decided to purchase an OSEPP tank robot ($89), with the OSEPP motor
> encoder kit ($27). I also bought the OSEPP wheel kit in case I'm not
> happy with tank treads. Things are beginning to arrive via the mail,
> sometimes a bit of a wait on this other side of the world.
>
> My total set of inputs and outputs are as follows:
>
> Inputs:
>
>    * bumpers (6 subminiature lever switches, ala Anderson's SR04)
>    * infrared sensors (Sharp GP2Y0D815Z0F with Pololu carrier,
>      with a range of 0.5 cm to 15 cm)
>    * sonar (processed through an Ultraborg)
>    * motor odometry (using OSEPP motor encoders)
>    * 9-DoF orientation (Adafruit 9-DOF Absolute Orientation IMU
>      Fusion Breakout - BNO055)
>    * ToF/LIDAR (Pimoroni VL53L1X Time of Flight Sensor Breakout)
>    * audio In (Adafruit I2S MEMS Microphone Breakout - SPH0645LM4H)
>    * several state setting toggle switches, including power kill
>    * Pi camera (for telerobotics)
>
> Outputs:
>
>    * motor controller (using a Thunderborg)
>    * servo control (provided by Ultraborg, for Sonar & LIDAR)
>    * audio out (Adafruit STEMMA Speaker - Plug and Play Audio Amplifier)
>    * LED indicators, plus 11x7 LED Breakout
>    * display screen (Adafruit Mini PiTFT - 135x240 Color TFT Add-on
>      for Raspberry Pi or PiTFT Plus Assembled 320x240 2.8" TFT
>      + Resistive Touchscreen)
>
> I've been using a Raspberry Pi Zero W and a 3 B+, will probably use the
> latter in the robot.
>
> Power will be from an 18V Makita power tool battery, sourced through
> the Thunderborg. I'm considering purchasing a PiJuice to separate the
> motor power from the Pi, but that's not really necessary.
>
> I'm pretty impressed by the Pimoroni Breakout Garden series of I2C and
> SPI modules. In particular, the ToF modules from Pimoroni and Adafruit
> (I've tried both) are amazing. The Pimoroni one has three range settings,
> and on long range measures up to 4 meters with high accuracy. Mounting
> one of these on a servo-controlled scanner provides an enormous amount
> of functionality for quite low power, weight and cost. I'm curious to
> compare how this works against an ultrasonic sensor. I will be mounting
> both on top of the servo, hoping to take advantage of the pros and cons
> of each.
>
> One of the benefits of many of the Pimoroni and Adafruit modules is
> that there's a python library available for each, with examples. This
> has allowed me to get things up and running quickly.
>
> Carl, I realise the total cost of my project exceeds your core budget,
> but I think it'd still be quite functional with just some bumpers and
> one of the long range sensors, e.g., the ToF sensor mounted to a servo
> (which comes with the tank project). If tank treads are an issue for
> DPRG contests OSEPP sell silicon wheels that fit on the same hubs, or
> you could repurpose the OSEPP 2-Wheel Balancing Mechanical Kit by adding
> a ball caster.
>
> I also realise that the above isn't a list of resistors and capacitors
> and ICs, but rather mostly finished components. I consider myself rather
> old-school, but with the availability of what's effectively a LIDAR unit
> for around $18 and the ability to have a tiny 3 gram circuit board provide
> nine sensor types (including two kinds of compass orientation, angular
> and linear accelerometers, gravity vector and ambient temperature) for
> about $35, well, kinda hard to think I'd build that myself. It is 2019,
> not 1979 after all. I can build a robot that is in some ways comparable
> to that Sojourner robot for about $800 dollars. Amazing.
>
> I don't have any sense yet of the kinds of projects that DPRG members
> create (i.e., what might be typical).
>
> If there's any interest in the project I would consider blogging about
> it as it progresses. I can for example explain some of my experiments in
> using Bluetooth as a means of mapping and orientation. These experiments
> will obviously progress better once I have a functional robot.
>
> My thanks for your patience in reading what turned out to be a long
> message; I'm happy to answer any questions. I hope this has been helpful.
>
> Cheers,
>
> Murray
>
> ...........................................................................
> Murray Altheim <murray18 at altheim dot com>                       = =  ===
> http://www.altheim.com/murray/                                     ===
> ===
>                                                                    = =  ===
>      In the evening
>      The rice leaves in the garden
>      Rustle in the autumn wind
>      That blows through my reed hut.
>             -- Minamoto no Tsunenobu
>
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