<div dir="ltr">Doug,<div><br></div><div>Great info! Seems there is always something new to learn :)</div><div><br></div><div>Judging from this survey of the pretty big DPRG d-list - and knowing how much people on this list scour sourcing options -
There seems to be a trend... Tons and tons of options out there, but nothing 'entry-level' that comes with encoders, which strikes me as a big gap. These off-the-shelf kits are all missing a critical foundational stepping stone.</div><div><br></div><div>I'm gonna suggest that in 2020 we build on what DPRG has learned between the 2016 club robot, the 'build-more-robots' series, and even this year's Donkey Car foray. The concept swirls around something / somewhere between those three platforms in cost and capability - but something where a reliable mechetronics platform can be programmed pretty-much out of the box - something that gives easier first steps for those with primarily software backgrounds. For sure let's chat in person as DPRG plans 2020! </div><div><br></div><div>- Carl</div><div><br></div><div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Sat, Nov 23, 2019 at 9:43 PM Doug Paradis <<a href="mailto:paradug@gmail.com">paradug@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif"><span style="font-size:12pt">Carl,</span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif"><span style="font-size:12pt"> One
of the most frequently asked questions by hobbyist roboticists is "How can
I make an inexpensive robot that I can grow with?". This was the quest
pursued by the DPRG 2016 Club Robot design. This design also had the mantra
that it would be built using "goodish" parts that would not need to
be replaced. </span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif"><span style="font-size:12pt"> </span></p><p class="MsoNormal" style="margin:0in 0in 12pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif"><span style="font-size:12pt"> A lot was learned from
the 2016 Club Robot, and I think that for a robot of its size it is a good
design. With its separate back and front plate assembly feature it is a very
configurable. The integral motor cage assembly insures good alignment between
the motors, making its’ tracking very accurate. The original design uses an Arduino Mega as
the main processor, which allows beginners an easy entry point to get started.
With David Anderson's (and Ron Grant) STM32 Nucleo breakout controller board, the robot
can be upgraded to ARM processors without extreme heart failure. Another
processor board configuration that includes a Raspberry Pi board is the
Pololu A-Star 32U4 Robot Controller SV with Raspberry Pi Bridge. The
chassis design, BOM, and a starting code base is available on DPRG's GitHub. There is also a series of videos to
show how to build it in its original configuration. The motors have
encoders.</span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif"><span style="font-size:12pt"> The
biggest issues with the 2016 Club Robot are:</span></p><ol start="1" type="1" style="margin-bottom:0in">
<li class="MsoNormal" style="margin:0in 0in 12pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif"><span style="font-size:12pt"> The
open source code base that we have on GitHub uses David's cooperative
scheduling multitasking system, which is not exactly beginner friendly. It
is powerful and not overly complex, but I admit that it can sometimes
cause problems when troubleshooting. However, this issue could be fixed by
adding an alternate code base that didn’t use the cooperative scheduling.</span></li>
<li class="MsoNormal" style="margin:0in 0in 12pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif"><span style="font-size:12pt"> The
laser cut chassis is not easily obtainable for people without access to a
laser cutter. Club members can always have one of the DPRG/DMS members cut
one for them for a nominal cost. Laser cut services are also available. Note:
You need to make sure your material thickness is the same as the design.</span></li>
<li class="MsoNormal" style="line-height:normal;margin:0in 0in 8pt;font-size:11pt;font-family:Calibri,sans-serif"><span style="font-size:12pt"> The
original design's front plate (front halve of robot) could be simplified.
Everyone modifies it. I would recommend a special purpose front plate be
created based by the roboticist for the desired primary task of the robot.</span></li>
</ol><p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif"><span style="font-size:12pt">
I am currently working on a smaller (~6" wheelbase) and simpler
robot that utilizes features from the 2016 Club Robot design. Its controller
board is a Raspberry Pi 3A board with a Pololu</span><span style="font-size:13.5pt"> </span><span style="font-size:12pt">A-Star 32U4 Robot Controller SV hat. This
provides motor controllers and a 32U4 (Arduino compatible) processor for real
time sensor processing. I plan to use the Rpi mainly for AI and vision
processing. It is powered by the 3500mAh 18650 batteries that you told me
about. I want to use this robot for testing Donkey Car code, and as my
Challenge LF robot (a different front assembly). It uses DFRobot metal gear TTmotor motors with encoders,
which I purchased from Mouser. If you are interested let me know.</span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif"><span style="font-size:12pt"> </span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif"><span style="font-size:12pt">
There are several off the shelf robot kits that have potential, but lack one or
more features. I have looked at the kits made by Sunfounder (see <a href="http://sunfounder.com" target="_blank">sunfounder.com</a>
or Amazon), they are like a host of kits coming from China and elsewhere. The
price for these kits is from about $70 to $130. They look like they are well
thought out, but they are limited by their cost constraints. It also depends on
what you want to do. They almost always lack encoders and use TTmotor TGP
yellow motors. Pololu offers kits that use "micro" gear motors, these
motors are fine for small robots and can be had with encoders. The Pololu
robots also have excellent documentation. I just personally don't like
their chassis as general robots, but I do own 2, a 3pi and a Balboa.</span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif"><span style="font-size:12pt"> </span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif"><span style="font-size:12pt"> I
would be interested in your reason for exploring robot learning platforms. If
you are looking at STEM activities, I think the Vorpal Hexapod robot (search
Thingiverse) would be worth considering as a starting point to generate
interest in robots. If you want a more traditional differential robot design,
the cheapest way is still the Amazon kit we used in the "Build More
Robots" training series.</span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif"><span style="font-size:12pt"> </span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif"><span style="font-size:12pt">
Let's talk at RBNO.</span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif"><span style="font-size:12pt"> </span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif"><span style="font-size:12pt">Regards,</span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif"><span style="font-size:12pt">Doug P.</span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:Calibri,sans-serif">
</p><p class="MsoNormal" style="margin:0in 0in 8pt;line-height:107%;font-size:11pt;font-family:Calibri,sans-serif"> </p>
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