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Low-cost, build-it-yourself robot for 4-H

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  • snit3snit3 Posts: 12
    edited 2012-01-10 07:32
    Yep. New to microcontrollers, but in the electronics industry for nearly 60 years. I must say though, I may be getting too old to deal with this stuff! Fortunately, I'm retired and can spend all day trying to do the simplest things. :-(
  • TtailspinTtailspin Posts: 1,326
    edited 2012-01-10 09:08
    Hey John R., I just wanted to cheer you on, This is a wonderful project, :thumb::thumb:
    It looks like you have everything under control, Keep us updated, and Keep up the good fun...

    I don't have much to add to the project, Other than I think some "inexpensive" encoders would be a great idea...


    -Tommy
  • John R.John R. Posts: 1,376
    edited 2012-01-11 18:16
    Ttailspin wrote: »
    Hey John R., I just wanted to cheer you on, This is a wonderful project, :thumb::thumb:
    It looks like you have everything under control, Keep us updated, and Keep up the good fun...

    I don't have much to add to the project, Other than I think some "inexpensive" encoders would be a great idea...


    -Tommy

    The cheering is more than enough to "add", I am hoping to have time to play with some form of encoder before the presentation. I'll post it here, if not before, then after.
  • John R.John R. Posts: 1,376
    edited 2012-01-11 18:18
    The robot is powered well by the 4 AA battery pack, but at times it approaches and crosses brown out. Anyone have a suggestion for capacitor size across Vdd and Vss? The capacitor almost has to go on the breadboard end of things.
  • TtailspinTtailspin Posts: 1,326
    edited 2012-01-12 07:00
    You might could look into using this thingy >>> Boe-Boost <<< but I am not sure what the QS board will do with 7.5 volts.


    -Tommy
  • Oldbitcollector (Jeff)Oldbitcollector (Jeff) Posts: 8,091
    edited 2012-01-12 08:16
    @John,

    What an AMAZING project! and Open Source too! Budget robotics.. I'm blown away man!

    OBC
  • Martin_HMartin_H Posts: 4,051
    edited 2012-01-23 06:34
    Do you have any printable templates for cutting the base? I just had an idea what to do with the BOE I was given. As a group project the scouts will build one of these and we'll try things like roaming with whiskers and writing names. I have enough spare parts laying around to prep this for a February den meeting.
  • John R.John R. Posts: 1,376
    edited 2012-01-23 11:28
    Martin_H wrote: »
    Do you have any printable templates for cutting the base? I just had an idea what to do with the BOE I was given. As a group project the scouts will build one of these and we'll try things like roaming with whiskers and writing names. I have enough spare parts laying around to prep this for a February den meeting.

    Martin; Parallax is working on a couple final "tweaks" to help easy assembly. Once they are done, the intent is to make things available. I'll be talking with them this week, and will make a point of getting the DXF and/or PDF files.

    There should also be some code avaialble this week from me. There may also be some materials from the Parallax Education team, but I'm not sure when they will be ready for "public consumption". I'll be bugging them next week.
  • techberthtechberth Posts: 5
    edited 2012-01-23 12:30
    what abt the price??
  • John R.John R. Posts: 1,376
    edited 2012-01-23 15:07
    techberth wrote: »
    what abt the price??

    That is an interesting question, with lots of variables.

    The intent of this project is not necessarily to come up with an actual "kit" that will be a product. This is meant more as a demonstration of concept, and a way to get away from other "kit" robots, and be dealing with relatively "raw" electrical components.

    Ken and the rest of Team Parallax will need to determine if there will be a kit for sale, what components would or would not be in the kit, etc.

    Some of what happens may also be determined by the 4-H community and educators. They are searching for answers, and have a number of directions that they could head. It seems that different levels, and different geographic areas have different needs and wants.

    Ken: any follow up from the Parallax side?
  • prof_brainoprof_braino Posts: 4,313
    edited 2012-01-23 16:01
    One of the guys from Chibots.org said that a very popular event was robot sumo.
    The kids would arrive and buy a "kit" - a bag of parts with micro controller, motors, and sensors, etc;
    they would build the kit and and start pushing each other out of the ring. Which worked well, since not everybody finsihed at the same time.

    This sounds like it might be a convenient basis for another event. I'll post whether the club takes this route and how it goes.

    This might also mesh with our efforts on the BSA merit badge.

    Thanks for all the work you put into it. :)
  • Cats92Cats92 Posts: 149
    edited 2012-02-07 23:10
    Hello,

    I like it !

    Build something like that with a group of kids ("Hands on project : La Maison des Sciences / France" )
    See picture.

    Here the net site of the robots for kids : http://cats92.free.fr/ROBOTS/Formation/Index.htm

    I think we need something to program it with blocs : very easy to use and open : have an idea ?.

    Jean Paul
    800 x 532 - 112K
  • rcricercrice Posts: 7
    edited 2012-02-08 18:54
    Ken - this is extremely interesting since I am working with my son's very large boy scout troop to start up a Robotics Merit Badge program. The merit badge is more of an introduction or "taste" of a subject, as opposed to what sounds like a more continuing club type program the 4H seems to have.

    For the first go round, I have a stack of BOE-Bot kits. While Robotics with the BOE-Bot is an excellent book, I think it is probably not quite the right tool for the job for a robotics intro that will last only a couple of Saturday afternoons. I'm deep into creating a construction handbook focused specifically on assembling the boe-bot kit. What I'm doing is along the same lines of the homegrown wiring guide already posted here.

    One reason I like the BOE-Bot kits for this (aside from the reasonable cost) is that the Gui-bot programming tool is available. The merit badge requirements are either program the robot OR draw a flow chart of what you want it to do, leaving the programming to someone else. I believe that the gui-bot tool will let our Scouts dive in and do programming on their own very, very quickly. For a short term class, I think that is important.

    What I wish is that the Gui-Bot programming tool could do more. I'd really like a graphical drag and drop environment that would give the scouts more complete control over the robot. Build that, and I'll be really, really happy.

    Robert
  • CowboyCoderCowboyCoder Posts: 33
    edited 2012-02-09 07:37
    For anyone that is trying to setup a 4-H Robotics Club.

    I started a 4-H Robotics Club in my area several years ago that was designed as a totally freeform robotics build, program and play group. I did not follow the 'prescribed' 4-H LEGO Robotics Club as I just didnt see my group getting anyhting out of it. We just built what fancied us, under the umbrella of some specific task, ie. line following etc.. and had fun.

    Work with your local schools. Both my local High School and Jr. High School made space available for my clubs to meet as part of an after school program. Meeting at the schools led to a paid teaching job, teaching robotics, as part of an after school grant program.

    If anyone needs any help setting up a 4-H club or ideas on how to run a club with the most effect, feel free to drop me a line.
    Update - Ken Gracey has my personal contact info for anyone that needs more contact than IMs here in the forums.

    For me, it has been a great, several year blast to see all those "AH HA" moments.

    The only dissapointing thing was the lack of parental involvement... it is what it is I guess.
  • John R.John R. Posts: 1,376
    edited 2012-02-11 07:07
    Well, I'm finally back home from St. Louis and the presentation to the 4-h Educational leaders of the North Central Region (ND, SD, KN, MO, IA, MN, IL, WI, IN, MI, OH). It went great!

    The Science Conference focused on Inquiry Learning, this is a change from the 4-h focus of Experiential Learning, and to be honest, I haven't quite wrapped my head around the differences yet. Oversimplifying it, the process involves stimulating questions and "inquiry", and then doing research, experiments, etc., followed by sharing and reflection. Very powerful stuff in the world of science, and very important life skills.

    Presenting the robot here, doing the assembly and a dash of programming, went over very well. Besides having fun, the group was VERY interested in a program that could take older 4-h members past the NXT robots. There seemed to be an agreement that this type of robot, or variations (DC motors, different chassis) was a great way to go. There were a couple of folks there who had worked with other processors, and they expressed interest in exploring the Propeller! There was a mixed feeling on if the "chassis" should be included or not. For the most part, this was based on the time frame people intended to use the kit (Science Saturday => Include the chassis / Program or Club, have the kids build one).

    From shortly after submitting my proposal, I started getting a feeling that 90 minutes was a short time. Well, it was even shorter than I thought, but the majority of the group decided we wanted to keep going, and we found another room to move to. We all "skipped" the next session to keep going, and everyone not only finished the robot and downloaded the "demo" code, they were also able to program the whiskers to light an LED!

    It was a great experience, and after the session, it was hard to go anywhere without being stopped, not just by people in the session, but others that had heard about it.

    The next steps here are to pull together the documentation for this specific robot. I'll also be working on putting together some thoughts on what a full fledged program will look like. There were discussions about possibly having a "robotics" conference for the region. I'm not sure if that will happen, due to time commitments and budget restraints of the University Extension Systems.

    I would encourage anyone here to seek out your county 4-H agent and look into becoming involved with 4-H. There is a national emphasis on STEM, and robotics was one of the leading components to be embraced. In general, each county has an "extension office" that is part of the "Land Grant University System", and each office has a 4-H Agent. They are a great starting point.
  • prof_brainoprof_braino Posts: 4,313
    edited 2012-02-11 22:25
    Thanks for leading the way on this. There are at least a few of us that wish to learn how to do what you are doing. Good work!
  • ercoerco Posts: 20,256
    edited 2012-02-13 10:19
    Devil's Advocate:

    Is yet another differential drive robot really the best starter robot? There's no shortage of them already. A car-type robot with one rear drive motor and one-servo car-type steering may be probably cheaper and more intuitive than a diff-drive robot. I taught a class to art students a while back, and everyone was able to build theirs and get it moving in one class period. Turning-wise, not as agile as a diff-drive bot, but far easier to go straight. An "encoder" could be as simple as a microswitch on the drive wheel counting full rotations.

    I'll throw out another challenge here, I'll build one using a lowly BS1 and and go head to head in a simple figure 8 navigation contest with someone building yet another diff drive robot with a BS2 and CR servos. Price, simplicity, build time, and accuracy are paramount here.

    Duane? Martin_H? Microcontrolled? Who will answer the call? :)
  • Martin_HMartin_H Posts: 4,051
    edited 2012-02-13 11:55
    erco wrote: »
    I'll throw out another challenge here, I'll build one using a lowly BS1 and and go head to head in a simple figure 8 navigation contest with someone building yet another diff drive robot with a BS2 and CR servos. Price, simplicity, build time, and accuracy are paramount here.

    Well you've already got the aRobot which except for using a BS2 is already that sort of robot. IIRC it wasn't so accurate.

    It just so happens that I'm working on a proof of concept for a BS2 powered diff drive robot that uses a single encoder. But not a normal sort of wheel encoder at all. If the POC works I can build the production model with parts I have sitting around the house.
  • rcricercrice Posts: 7
    edited 2012-02-13 12:07
    I'll grant that differential drive is trickier to get the hang of.

    But, build time for a BOE-bot is not that high. I'm working on getting a Robotics merit badge course nailed down for my son's Boy Scout Troop.

    My 13 year old was able to build a Boe-bot kit in just under an hour, including stops for cookies and harassment of little brother. That got him far enough that he was ready to program movement via the gui-bot software. No sensors, but in a ready to drive configuration.

    That was with a set of condensed instructions. Working from the suplied book would definitely taken him longer.


    Robert


    erco wrote: »
    Devil's Advocate:

    Is yet another differential drive robot really the best starter robot? There's no shortage of them already. A car-type robot with one rear drive motor and one-servo car-type steering may be probably cheaper and more intuitive than a diff-drive robot. I taught a class to art students a while back, and everyone was able to build theirs and get it moving in one class period. Turning-wise, not as agile as a diff-drive bot, but far easier to go straight. An "encoder" could be as simple as a microswitch on the drive wheel counting full rotations.

    I'll throw out another challenge here, I'll build one using a lowly BS1 and and go head to head in a simple figure 8 navigation contest with someone building yet another diff drive robot with a BS2 and CR servos. Price, simplicity, build time, and accuracy are paramount here.

    Duane? Martin_H? Microcontrolled? Who will answer the call? :)
  • ercoerco Posts: 20,256
    edited 2012-02-13 12:24
    Martin_H wrote: »
    Well you've already got the aRobot which except for using a BS2 is already that sort of robot. IIRC it wasn't so accurate.

    It just so happens that I'm working on a proof of concept for a BS2 powered diff drive robot that uses a single encoder. But not a normal sort of wheel encoder at all. If the POC works I can build the production model with parts I have sitting around the house.

    I'll take that as a "yes", Martin_H! Wanna hear more about your offbeat encoder...
  • Martin_HMartin_H Posts: 4,051
    edited 2012-02-13 12:46
    erco wrote: »
    I'll take that as a "yes", Martin_H! Wanna hear more about your offbeat encoder...

    Look for a new thread shortly with the outcome of my POC irrespective of success or failure. If it fails I will have my tail between my legs. If it works I will be full of bluster.
  • ercoerco Posts: 20,256
    edited 2012-02-13 12:47
    Brimming with hubris? :)
  • CowboyCoderCowboyCoder Posts: 33
    edited 2012-02-13 19:16
    Hey all,

    I am not trying to shoot anyone down, but from my experience with 4-H, you will get alot further with the kids (age dependant of course) with a grab bag of parts rather than canned kits. We could argue all day how kits are better this, or better that, even faster to develop, but there is no race going on. And yes, I sell a couple of kits myself.

    Fill up a box with 'stuff', present it to the kids, and in keeping with 4-H, lead. Let them discover. Teach them about the tools we use, how and why. Teach them how to hook things up, how to program them and how to test them. There is very little scientific method in a kit, tons in a grab bag of parts.

    Ask yourself, what discovery is there in a kit? Hmmm, put it together, feed it canned code and watch it do exactly what is was designed to do?

    Of course the answer is TIME? There are no clocks in 4-H really.

    One comment from a parent from a few years ago - "those kids can't program robots, they are too young." Her son won the line following event we built and programmed for...
    He was 10.

    I am not trying to take anything away from kit robots. The BoeBot is great, as well as a few others. All I am showing here is my experience, yours may vary.

    Before you start, carefully read what 4-H really means...
  • Cats92Cats92 Posts: 149
    edited 2012-02-16 12:56
    Hello,

    I like John R project as it seems open and affordable for kids.

    On the programming side one can hope a GUI with blocks and colors with a lot of exemples.

    Last week i try the Minibloq GUI (here: http://minibloq.net/) with an Arduino : loaded it and ten minutes later i have a led blinking on a Duemilanove .



    With GCC coming perhaps we may have something like that ?
  • John R.John R. Posts: 1,376
    edited 2012-02-22 17:35
    We are working on getting the drawings for the acrylic base components available in a format that can be widely used. I'm also working on a series of assembly photos.

    I've also attached the "demo code" I used for the presentation. This is not the "most sophisticated" code, but the purpose was to provide a starting point for those wishing to dig deeper. The RobotDemo.spin file uses the buttons on the quick start as follows (from Left to Right, or 7 to 0):
    • 7) Stops the robot and exits the program (to allow the prop to shut down to preserve batteries.
    • 6) Drives forward until the "Stop" button is pressed.
    • 5) Drives backward until the "Stop": button is pressed.
    • 4) Does a clockwise spin turn until the "Stop" button is pressed.
    • 3) Does a counter-clockwise (anti-clockwise if you prefer) spin turn until the "Stop" button is pressed.
    • 2) Drives forward until either one of the whiskers is activated and stops.
    • 1) "Whisker Navigation" - Drives forward until a whisker is activated, the robot backs up, turns away from the activated whisker, and then resumes forward travel.
    • 0) Stop Button, stops any action initiated by buttons 1 - 6.
    The RobotTemplate.spin file is an "empty" template that is far from empty. The menu is stipped to do nothing except for button 7 (Stop and Exit). There are none of the supporting functions used in the demo, but all of the constants and variables are defined, as well as the structure for the menu, and required objects (Servo and Buttons) are all in place. Basically, this template is ready to start adding robot motions.

    At the presentation, we just used the template to blink and LED. This was not the plan, but was what time allowed. Most of those in attendance were not electronics or robot type folks, but science educators or 4-H "agents" (general 4-H educators and coordinators).
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2012-02-23 12:04
    John,

    It's great to hear your presentation was such a success! The button selected programs concept reminds me a bit of the Scribbler demo. Of course, for more advanced users you could provide more sophisticated demos which could also be selected by the built-in buttons.
  • John R.John R. Posts: 1,376
    edited 2012-02-25 11:43
    Here is an AutoCAD 2000 version of the acrylic parts, both in DXF and DWG formats. If anyone needs an additional format, let me know, and I'll see what I can do. I am hoping to get some "Assembly Pictures" done this weekend, but that is "questionable" to be honest.

    4H Robot - Acrylic Parts.dwg

    4H Robot - Acrylic Parts.dxf
  • doggiedocdoggiedoc Posts: 2,243
    edited 2012-02-26 03:49
    Looking good JohnR. Congrats on your successes thus far. Keep it up!

    P
  • Cats92Cats92 Posts: 149
    edited 2012-03-16 07:00
    Hello,

    i tested the idea with a box of ( selected) parts i gave to a group of kids (12 years old) and a short library of functions (motors.forward, backward, left, right, spinclockwise, spinanticlockwise, start, stop)

    Let then tinker with it.

    They draw squares, circles and stars with the pen.


    Quite agree with Raffy and CowboyCoder it is the best tool i ever try with a group, much better than kits : they like to create something

    Now we have to find simple and attractive activities around that !

    Cats92
  • blantonreblantonre Posts: 1
    edited 2013-12-06 00:39
    Hi CowboyCoder,
    I'm new to microcontrollers and am working on a follow the line robot (similar to izebote) with three IR Reflectors. How does this code look to you?

    '{$STAMP BS2sx}
    '{$PBASIC 2.5}

    ADC_L VAR Word 'Analog/Digital Converter - Left
    ADC_R VAR Word 'Analog/Digital Converter - Right
    ADC_C VAR Word 'Analog/Digital Converter - Center
    S_LIGHT CON 200 'Constant for light set at 200

    INIT: IF (IN0=0) THEN 'SWITCH P0 is being pressed (turn on)
    PAUSE 500: FREQOUT 11,10,800
    GOTO MAIN
    ENDIF
    GOTO INIT

    MAIN:
    DO
    GOSUB FORWARD: PAUSE 50
    GOSUB RD_ADC
    IF (IN1=0) THEN 'SWITCH P1 is being pressed (turn off)
    PAUSE 500:FREQOUT 11,10,800
    GOSUB MOTOR_OFF: PAUSE 5000
    ENDIF

    'DARK = HIGH NUMBER, LIGHT = LOW NUMBER
    IF (ADC_L>ADC_C) AND (ADC_R>ADC_C) THEN
    GOSUB FORWARD: PAUSE 50
    ELSEIF (ADC_L>ADC_C) AND (ADC_R<ADC_C) THEN
    GOSUB S_RIGHT: PAUSE 150
    ELSEIF (ADC_L<ADC_C) AND (ADC_R>ADC_C) THEN
    GOSUB S_LEFT: PAUSE 150
    ELSEIF (ADC_L<ADC_C) AND (ADC_R<ADC_C) THEN
    GOSUB MOTOR_OFF: PAUSE 5000
    ENDIF
    LOOP

    RD_ADC:
    'IR SENSOR LEFT
    LOW 10: PAUSE 2: HIGH 10
    SEROUT 10,240,[1] 'Using ANALOG NO.1
    SERIN 10,240,[ADC_L.BYTE0, ADC_L.BYTE1]
    DEBUG "ADC_L: ", DEC ADC_L, CR


    'IR SENSOR RIGHT
    LOW 10:PAUSE 2:HIGH 10
    SEROUT 10,240,[3] 'Using ANALOG NO.3
    SERIN 10,240,[ADC_R.BYTE0, ADC_R.BYTE1]
    DEBUG "ADC_R: ", DEC ADC_R, CR


    'IR SENSOR CENTER
    LOW 10:PAUSE 2:HIGH 10
    SEROUT 10,240,[5] 'Using ANALOG NO.5
    SERIN 10,240,[ADC_C.BYTE0, ADC_C.BYTE1]
    DEBUG "ADC_C : ", DEC ADC_C, CR
    RETURN


    '+++++ Movement Procedure +++++++++++++++++++++++++++++
    FORWARD: HIGH 13 : LOW 12 : HIGH 15 : LOW 14 : RETURN
    BACKWARD: HIGH 12 : LOW 13 : HIGH 14 : LOW 15 : RETURN
    T_LEFT: HIGH 13 : LOW 12 : LOW 15 : LOW 14 : RETURN
    T_RIGHT: LOW 13 : LOW 12 : HIGH 15 : LOW 14 : RETURN
    S_LEFT: HIGH 13 : LOW 12 : HIGH 14 : LOW 15 : RETURN
    S_RIGHT: HIGH 12 : LOW 13 : HIGH 15 : LOW 14 : RETURN
    MOTOR_OFF:LOW 12 : LOW 13 : LOW 14 : LOW 15 : RETURN
    '++++++++++++++++++++++++++++++++++++++++++++++++++++++



    I have three IR Reflectors and show the output in the debug window. They appear to be working ok. My robot is not following the line though with this code. Any suggestions will be appreciated.
    Bob
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