Tutorial: J2r Robot

  1. 4mem8's Avatar
    4mem8 4mem8 is offline T-1000
    Mod, Hack

    J2r Robot

    Estimated Time
    Approx 5hrs
    Skills Required
    Knowledge of soldering, Metal work fabrication, Electronics
    Parts Required
    Aluminum, LEDS, Acrylic sheet.
    Tools Required
    Soldering iron, Pliers, metal vice, Drill press, Hammer, drill bits.
    I had been waiting impatiently for my J2 Robot -- which is a complete robot by J2R Scientific that is ready to run out of the box.

    Its design is part of the REOP (Robotics Education and Out Reach program of The Robotics Club of Yahoo).

    Justin Ratcliff's Vision

    Justin Ratcliff designed this robot as a security robot after the 9-11 attacks.After dedicated thought into all aspects of what a security robot would require, Justin decided it was better to start small so he could more easily model the behaviors and systems he needed. Among the features he wanted to experiment with are Subsumption programming and the new PING sonar range modules from Parallax, Inc.

    Justin deliberately made it hackable -- the device is designedto make it easy to add and remove components. With that in mind, he picked the Basic Stamp II as his micro-controller, and chose :

    * a standard sensor compliment of Sonar for navigation,
    * IR for close up and Edge detection,
    * CdS photo cell for light level and
    * a multi-input port for multiple switch

    I was particularly looking forward to watching it roam the room using its ultra-sonic sensor scanning up and down to see where it is going. I just love watching a robot identify an edge or an object -- and then back up to a safe distance.

    Inputs are from either a keypad or several bump sensors. And the 'bot has two continuation Rotation servos for drive motors and a servo controlled neck for the sonar to look up And down.

    Finally the design attempts to make the 'bot look interesting and have a voice. There is a speaker and Justin wanted to experiment with the new Text-to-Speech Emimic board from Parallax.

    As for looks: This robot bears quite a resemblence to "Short Circuit," the robot who appeared in two films in the mid-80’s. I saw both movies 3 times, and I would still recommend them to anyone who hasn't seen them yet.

    With all that as an introduction: here are the modifications that I felt had to be made for my personal use. (I am working on a video, and will share that when it's done).

    Just unpacked this amazing Robot.
    I've been checking out the very popular BS2 stamp, the 3 servos (two for the drive and 1 in the neck for the U/S sensor), 1 IR GP2D12 sensor and 1 LDR sensor. It came with numerous accessories (more on that in few days). <img alt="">
    Here are the technical specs of this robot.

    My First impression:

    The assembled J2R (Hmmm...) leaves a bit to be desired.
    The servos,sensors,batteries,S/S body,wheels and circuit board are pretty good.
    However the base [.5 mm S/S] is too flexible and distorts, I plan to use 5mm acrylic sheet for the base. The wiring from circuit board to sensors was bad. Some of the female plastic plugs were melted from excess heat when soldering. These had to be replaced with parallax female leads cut in half. This left a neat female plug to fit on to the circuit board pins.
    The mounting of the servos was particularly bad as they were not parallel with the base and needed to be redone.
    All this aside: it is a very interesting robot!
    I have done all the mods needed to make this bot as I would have expected from the designer as an assembled kit.
    Here are the mods in order that i did them.

    Alloy brackets for the servos to be bent to shape.

    Alloy brackets for servos bent, drilled and notched for servo leads.

    Servos and wheels with brackets.

    Servos and wheels different angle.

    Brackets mounted to acrylic base with servos.

    5mm Acrylic base that replaces the .5mm S/S steel base.

    Alloy bracket for battery pack in center.

    Mounting studs for BS2 circuit board.

    BS2 circuit board in place.

    Close up of BS2 circuit board and wiring.

    Sharp GD2P12 IR distance sensor.

    Alloy bracket for GD2P12 sensor.

    Base modifications made,Neck servo and sensors ping sonar,mouth led,CDS sensor and spkr.

    Arms and S/S body in the background.

    Ping sonar with mouth led mod.

    New sonar alloy bracket with servo horn attached,

    Another view inside of mount.

    Sonar mounted on Alloy bracket and servo horn bolted in place.

    J2's eye brows.

    J2's eye brows in place.

    Two alloy brackets for securing the neck servo, once the servo is in the lower one the top one fits over the lower one.

    Neck servo in bracket.

    Sonar bracket mounted to neck servo.

    Whole assembly now fitted to neck servo.

    Neck/head assembly fitted to J2's S/S body and alloy arms fitted.

    Side view of J2 reading the BS2 manual.

    Here's looking at you.
    July 5, 2007:
    I have a small problem at present with the software not loading to the BS2, I have emailed Justin to find out why, and am waiting for a reply.

    This is what I have found out so far.

    Ok, I managed to download the program to my BS2P24/40 demo board ok, So I know that both the serial on Com 1 and my USB to serial on com6 work ok.

    These are the results in my stamp editor 2.2.6

    Version Loopback Echo

    v1.3 Yes Yes

    Com1 Basic stamp 2p40 [Stamp recognized]

    This also works with USB Com 6

    So, Why does it not work with both the BS2 boards??????

    It's not the editor or Com ports at fault or leads.

    I have also managed to put one of the bs2 stamps in my demo board and download that program ok, verified by the editor as ok, BUT when inserted in the robot's board nothing. Dead as.

    My BS2P24/40 Demo board.
    I have now loaded Justin's software to this setup and it works fine, However it will notI load to his BS2 stamp circuit.
    Update 6th July

    Dohh what a dummy!
    After doing all the tests above and finding out that both BS2's were working ok with my demo board I decided to check with a multimeter [continuity] all of the power lines only to find that I was only getting 3.75v at the CPU VDD side and only 5.75v at the reg, I had assumed that the new batteries supplied [6]= 9v were new or full charge, However they were NOT. Replaced with known good batteries and viola I could now download programs to J2R.
    Have now got most things working on J2, Have a bit of tidying up to do then I will make a video.
    Thanks Justin for a great robot!

    Video link
    People yearn after this robotic dream, but you can't strip your life of all meaning, emotion and feeling and expect to function.

Replies to Tutorial: J2r Robot
  1. Join Date
    Sep 2006
    Carol Stream, Illinois

    Re: J2r Robot

    nice set of mods 4mem8! I take it those beeps in the video are J2R detecting it's bout ready to fall off the edge?

    �In the long history of humankind (and animal kind, too) those who learned to collaborate and improvise most effectively have prevailed�
    - Charles Darwin

  2. Join Date
    Apr 2008
    Nelson, New Zealand

    Re: J2r Robot

    Hi Alex, Yes those beeps are indicators as to what J2 is doing sensor wise. Pleased you liked the tutorial. More to come.
    People yearn after this robotic dream, but you can't strip your life of all meaning, emotion and feeling and expect to function.


Closed Tutorial