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Quickstart Li-Ion Powered Toddler!! — Parallax Forums

Quickstart Li-Ion Powered Toddler!!

doggiedocdoggiedoc Posts: 2,241
edited 2011-12-13 16:23 in Robotics
Hey y'all :D

I have been tinkering with my Toddler again for the last few days and decided a transplant was in order.

prop_toddler.jpg


I removed the original Toddler board and AA battery pack and replaced them with the Li-ion Power Pack-Charger and the MSR-1 Propeller Robot Control Board. I don't know if anyone else has done this yet and a search of the forums yielded nothing as such. I figured I would share as this progresses.

Next on the agenda - programming the beast!!

Paul
«1

Comments

  • Duane DegnDuane Degn Posts: 10,588
    edited 2011-11-30 13:43
    Very cool. Thanks for taking time to document your efforts.

    That thing is a beast. Maybe it could be your automated dog walker.
  • doggiedocdoggiedoc Posts: 2,241
    edited 2011-11-30 13:49
    Duane - I've got my jaw set on a QuadRover as an autonomous dog walker. I'm pretty sure even one of my 3 pound Chihuahuas could drag the Toddler like nothing. :D
  • PublisonPublison Posts: 12,366
    edited 2011-11-30 14:27
    Oooohhh..Looks like Ken sent you a new LI-ion charger pack too!

    My camera is not working right now, but I have the brains for a QuadRover on my Gold Toddler right now, working through the programming.

    I have a second Propeller Control Board Propeller Control Board (#28205) for a QuadRover that needs to go onto a QuadRover that is just sitting at Parallax without a brain. I'll pay the shipping.

    I'm sure the Control Board represents at least 80% of the cost of the whole robot. I'd be doing Parallax a favor :)

    I will be following your transplant saga, and will share mine.
  • doggiedocdoggiedoc Posts: 2,241
    edited 2011-11-30 14:42
    Can you still buy the QR controller board?


    EDIT: I don't see it on the site anymore. I seem to remember you could buy them separate from a quadrover at one point. Maybe I dreamed that.
  • BrowserBrowser Posts: 84
    edited 2011-11-30 15:07
    ur shop iz too neet. needz cat to increes intropy, push screwz on floor.

    -browz
  • PublisonPublison Posts: 12,366
    edited 2011-11-30 16:43
    doggiedoc wrote: »
    Can you still buy the QR controller board?


    EDIT: I don't see it on the site anymore. I seem to remember you could buy them separate from a quadrover at one point. Maybe I dreamed that.

    Paul,

    They blew them out a year or so ago. I got two of the last six.

    Jim
  • PublisonPublison Posts: 12,366
    edited 2011-11-30 16:44
    Browser wrote: »
    ur shop iz too neet. needz cat to increes intropy, push screwz on floor.

    -browz

    Scews? I bet you look for the smallest SMD devices to push on the floor! Poor Phil :)
  • doggiedocdoggiedoc Posts: 2,241
    edited 2011-11-30 16:55
    Publison wrote: »
    Paul,

    They blew them out a year or so ago. I got two of the last six.

    Jim
    Want to sell one?
  • PublisonPublison Posts: 12,366
    edited 2011-11-30 17:12
    doggiedoc wrote: »
    Want to sell one?

    Gotta sleep on that one Doc. I was going to use it in a QuadfCopter, unless the HoverFly Open is affordable.
  • doggiedocdoggiedoc Posts: 2,241
    edited 2011-11-30 19:38
    @Publison - just PM or email me : doc@tcah.com

    @anybody - - what is it about the Toddler Servos and the MSR1's Headers to IO P0-P23 that don't get along. Is it a ground loop issue caused by the level shifters to the pins? I can connect a Hobbico Command standard servo and it responds as expected and I can connect the Toddler servo to the QuickStart board and run the same code and it responds as expected. :(
  • doggiedocdoggiedoc Posts: 2,241
    edited 2011-11-30 20:53
    Got it! This post helped me figure out the problem. The level translators are getting discombobulated by the capacitive load of certain servos. I guess. :innocent: Any who - bypassing the level translators for the signal did the trick. Now, if I can just make the wires look neater. :D
  • doggiedocdoggiedoc Posts: 2,241
    edited 2011-12-01 06:36
    UPDATE: Some crude walking accomplished! Need to fine tune still and will post some video tonight!
  • doggiedocdoggiedoc Posts: 2,241
    edited 2011-12-01 17:41
    VIDEO! Baby steps, but at least it's walking!

    [video=youtube_share;k7PjQnzGzTE]
  • doggiedocdoggiedoc Posts: 2,241
    edited 2011-12-01 17:43
    Here's another angle... sorry it's so "yellow", dang incandescent lights!

    [video=youtube_share;mPPhcTkiL7M]
  • doggiedocdoggiedoc Posts: 2,241
    edited 2011-12-01 17:54
    Here's the code that uses Beau Schwabe's Servo Object:

    The zip file contains the supporting objects for convenience.
    spin
    spin
    Toddler_Servo_test.spin
    6K
    zip
    zip
    Toddler_Servo_test.zip
    10K
  • doggiedocdoggiedoc Posts: 2,241
    edited 2011-12-02 21:13
    Soooo...... I realized something. Using a discontinued control board may not be the best of ideas. I originally planned to use the QuickStart board since they are readily available and pretty inexpensive. Guess I'll get back to that! And I just got in today the smaller Li-ion Boe-Bot Power Pack-Charger and I already have a few P8X32A QuickStart boards.

    So I've got this to work with....

    prop_toddler2.jpg

    Turns out the P8X32A QuickStart board and the Li-ion Boe-Bot Power Pack-Charger aren't directly drop in parts. I'll need to tap some now holes it seems.


    Paul
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2011-12-03 04:05
    I suppose I should get one of those Li-po boards. My Toddler has two 3xAA packs attached to its legs for the lower center of gravity. I just started a break-down and rebuild with the intention of making my work with the twin PWM timers on a SX-48 board. Something about the air in Kaohsiung has faded the blue, so it is being painted flat black.

    It is very appealing to just bump ahead and use a Propeller, but I've wanted to make the SX-48 work for some time as I finally comprehend SXASM.
  • doggiedocdoggiedoc Posts: 2,241
    edited 2011-12-03 04:11
    I started learning SXASM before the Propeller came out. I didn't get much further than blinkey LEDs! LOL I still may play with them one day since I still have a few. I don't expect to ever become proficient at them though. For that matter, I'm just a hack with the prop - if I only had more time!

    How did your Toddler work with a lower center of gravity?
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2011-12-04 00:54
    SXASM has been a very useful stepping-stone for me, but I must admit that I've been a very slow learner.

    Much of what is done in Assembly code for robotic requires slowing processes down to respond to real world responses. So learning to create timers and delays in software are quite important. Another topic is PWM, as it is both the basis of servo control and can be used for DAC. Then there are just counters for RCTIME functions.

    The rest seems mostly to be conversions of serial to byte (or other word length data) or vise-versa. Traditional maths are not very useful as the micro-controller is more like a clock than a calculator. If you need intense number crunching, use a PC.

    I suspect that the Propeller would be better used for PID control than hobby servo control. After all the hobby servos merely require a signal every 1/50th of a second - not very fast.
  • doggiedocdoggiedoc Posts: 2,241
    edited 2011-12-04 04:38
    Loopy Byteloose wrote: »
    After all the hobby servos merely require a signal every 1/50th of a second - not very fast.
    I have 0.5 second delays in the code above to aid stride timing.
  • PublisonPublison Posts: 12,366
    edited 2011-12-04 07:25
    Lookin' good Doc!

    I didn't get a chance to respond before about the servo problem with the voltage translators. We had this problem before on the Propeller Servo Controller which uses voltage translators also. The thread is here:

    http://forums.parallax.com/showthread.php?118121-Digital-servo-s-on-USB-servocontroller

    .
    D    avid Carrier's response to the problem:
    The Propeller USB Servo Controller cannot drive loads less with than 5 kΩ of impedance. I have never seen servos that do not have high impedance inputs, but the oscilloscope traces you recorded are typical of a TXB0108 driving a low impedance load. If you do not need bidirectional communication, a series resistor of 5 kΩ or more will stop the ringing.

    The solution was to put a 5K resistor in line with the servo signal, (after the translator). Your solution was easier as the MSR1 has the capability to disable the chip in 8 port banks, but this was not possible on the PPSC.

    BTW, I going to keep the other QuadRover control board. You are wise to not use a discontinued card in a new project. :) I have an extra BoeBOT chassis that it needs to go on.

    Jim
  • zappmanzappman Posts: 418
    edited 2011-12-04 07:51
    Publison wrote: »
    Lookin' good Doc!

    I didn't get a chance to respond before about the servo problem with the voltage translators. We had this problem before on the Propeller Servo Controller which uses voltage translators also. The thread is here:

    http://forums.parallax.com/showthread.php?118121-Digital-servo-s-on-USB-servocontroller

    .
    D    avid Carrier's response to the problem:



    The solution was to put a 5K resistor in line with the servo signal, (after the translator). Your solution was easier as the MSR1 has the capability to disable the chip in 8 port banks, but this was not possible on the PPSC.

    BTW, I going to keep the other QuadRover control board. You are wise to not use a discontinued card in a new project. :) I have an extra BoeBOT chassis that it needs to go on.

    Jim

    @ Publison, Thanks for posting the link to the thread on the Propeller Servo Controller problems, as I just purchase one, I am sure your post just saved me a whole bunch of debugging / troubleshooting time.

    @ Doc, thanks for keeping everyone updated on your Toddler Brain Transplant.
  • doggiedocdoggiedoc Posts: 2,241
    edited 2011-12-04 09:07
    @Publison, @zappman - I was temporarily side tracked by my new Spinneret Web Server - but since I just fried it... I suppose I'll be tapping new holes for the Toddler's new power supply today as originally planned. :blank:
  • PublisonPublison Posts: 12,366
    edited 2011-12-04 09:35
    doggiedoc wrote: »
    @Publison, @zappman - I was temporarily side tracked by my new Spinneret Web Server - but since I just fried it... I suppose I'll be tapping new holes for the Toddler's new power supply today as originally planned. :blank:

    Bummer!

    Looks like your a man of many talents. Veterinarian, electronics, and hardware.

    I try to keep well versed in many areas, but I can say I have never operated on an animal before, (except for cleaning fish) :)
  • doggiedocdoggiedoc Posts: 2,241
    edited 2011-12-04 11:58
    Thanks Publison, but I'm not all that.

    Since I have a problem with drilling holes into my original Toddler deck plate, I decided to fabricate a new one. The best thing I had on had that I could easily work with was copper clad PCB. I used the original as a template.

    toddler_deck2.jpg

    toddler_deck1.jpg



    Then I used my dremel with a cutoff wheel to cut away the excess PCB.

    toddler_deck3.jpg

    toddler_deck4.jpg



    And finally, switched the dremel to the dremel press and drilled out the mounting holes and the holes for the battery pack.

    toddler_deck_done.jpg



    Now - I hope it mounts up strait! :D


    Paul
  • doggiedocdoggiedoc Posts: 2,241
    edited 2011-12-04 12:36
    Yay! The holes are where they are supposed to be!! Whew.


    toddler_deck6.jpg

    toddler_deck7.jpg




    :D
  • PublisonPublison Posts: 12,366
    edited 2011-12-04 13:00
    Was that a scalpel job or hacksaw. :) Either way nice job!

    I like the way the QS looks on top. Sweet!
  • doggiedocdoggiedoc Posts: 2,241
    edited 2011-12-04 13:03
    Publison wrote: »
    Was that a scalpel job or hacksaw. :) Either way nice job!

    I like the way the QS looks on top. Sweet!
    Dremel with a cutoff wheel. Makes it easy.
  • PublisonPublison Posts: 12,366
    edited 2011-12-04 13:11
    zappman wrote: »
    @ Publison, Thanks for posting the link to the thread on the Propeller Servo Controller problems, as I just purchase one, I am sure your post just saved me a whole bunch of debugging / troubleshooting time.

    @ Doc, thanks for keeping everyone updated on your Toddler Brain Transplant.

    Not trying to hijack doggiedoc's thread, but the information does have some merit. Attached is a picture of how I solved the servo problem on the PPSC. The same could be done on the MSR1. I designed some boards using 5K SMD networks to make it a little smaller, but the bulk of it is in the connectors.

    PPSC Fix.jpg


    PSC PCB.jpg
    PPSC Fix.jpg
    640 x 480 - 273K
    PSC PCB.jpg
    589 x 413 - 136K
  • PublisonPublison Posts: 12,366
    edited 2011-12-04 13:15
    doggiedoc wrote: »
    Dremel with a cutoff wheel. Makes it easy.

    Dremel+cutoff wheel+face mask? :)
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