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  • Author Author: genebren
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Mr. Machine gets an upgrade - Mostly working, but still needs a little some help.

genebren

In my prior blogs (Mr. Machine gets an upgrade - working on the pieces. , Mr. Machine gets an upgrade - new internals, motors installed and new PCBs , Mr. Machine gets an upgrade - time is running down  and Mr. Machine gets an upgrade - New boards, but not enough time ) I walked through Mr. Machine's history and some of my updates.  This time (for the second time, thanks to a extended due date, thanks Tariq) I will wrap up what I can as the project14 deadline closes.

 

For the most part I have written enough code to exercise the basic functions of the three boards that make up Mr. Machines electronics.  There was a fair amount of hacking involved to get some of the functions to work and the once pristine PCBs look like that have survived a war.  The most glaring of errors occurred in the LED dimmer circuit.  I have used the dimmer chip (TLC59731) before in another product, but it was a single LED channel.  In copying the circuit (which I designed a few years ago), I failed to remember that I single MOSFET in the serial path was both a switch (to suppress other serial traffic) and an inverter.  The inverter is used to invert the uart output to match the requirements of the dimmer chips requirements, so without it, I was unable to program the LEDs.  Also, due to the use of multiple LEd dimmers I needed to work out a method of injecting a fixed width low signal between programming bursts.  This one took a bit of head scratching, but I ended up using a time interrupt to signal when the serial stream should resume.  Here is an image of the PCBs prior to putting them all back into Mr. Machine:

Here are the PCBs getting attached to Mr. Machine's internal frame:

From here the internal frame (with attached electronics) was fitted into Mr. Machine's plastic skin.  It was during the assembly process that I ran into a problem.  Mr. Machine's old winding key was supposed to be repurposed into an on/off switch.  But once everything was in place (and because of the rework on the backside of the Power Pack, I noticed that the micro switch was push away from the cam assemble that should have pressed and released the switch.  I tried to shim and reposition things. but I was unable to come up with a clean solution.  With the deadline rapidly approaching, I decided to leave the key assemble out and I would use a pencil through the key hole to press and release the switch.  One mission objective scratched.

 

Speaking of scratched mission objectives, here are a few other features that fell off the table as I struggled to get some of the most basic features working.  Here are a few of the missing and/or limited features:

  1. Motor control - I had initially written a complex motor control function that included ramp up/down stepper controls and a multiple state state machine, but the debugging process was not going well, so I stripped the functions out and quickly wrote some simple code to read the R/C receiver outputs (direction/speed and turning) and convert them into appropriate stepper motor pulse patterns.
  2. Front and Rear IR sensors - I ran out of time to code the fail safe stops and inhibits associated with the sensors, so they were left off.
  3. LED light during movements - I had previously scratched the idea of getting LED lighting cues from the Midi player, but again with time running out, I left off any LED sequencing when Mr. Machine was moving.  I did a short LED sequence on power up for each board (shown below), the more impressive light show will have to wait for later.
  4. Winding key on/off switch - The final fit of all the pieces killed this feature.  I need to use a pencil to reach into Mr. Machine to reach the tiny micro switch to turn him on and off.

 

With everything installed inside Mr. Machine, it was time for a couple of quick (uneditted and very raw) videos of Mr. Machine in action.  First up is a video of Mr. Machine motors running on my desk top/workbench.  This video shows the speed and direction control of the two stepper motors.

 

 

 

Next up is a power up sequence, followed by the Midi file player playing "This Old Man" (a very fitting song given the creator of this project).  (Note: the audio is a bit distorted, but the case also seem to cause some resonance issues)

 

 

Finally, the proof video of Mr. Machine in motion.  I really struggled to speak in this video as I was rushing about trying to get things running and my brains were a bit scrambled.  I did experience some issues with the motors during this video.  I believe that these motors (even with their gear reductions) were a bit over loaded (not enough torque), but I does demonstrate forward/reverse and turning.

 

 

Once again, I would like to thank Tariq and the rest of the staff at element14 for givings us all a great place to gather and the opportunity to exercise our creative juices.  I had so much fun working on this project and I look forward to tuning this all up and working out the remain bugs and completing the features that did not make it in yet.

 

Note: attached are all of the source files for the various processors and PCBs.

 

Thanks and enjoy!

Attachments:
Mr. Machine.zip
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  • Excellent work . Though I wasn't able to follow your project from the start, reading your blogs now made me have the feel of how much effort went into the project, the pressure to complete things before the deadline. It literally put me on the edge of my seat while reading your project blogs from start to finish on whether or not the project will be finished on time with so much work and delayed PCB delivery. I am not good at 3D modeling yet but your works in this project serve as an inspiration and motivation for me.

     

    I love toys and those are basically my inspiration to work in the electronics field but this year I couldn't much concentrate on electronics projects (was busy with work and learning new technologies). Mr. Machine and You have pulled me back on track, thanks for that!

     

    Seasons greetings and a merry Christmas to you in advance!

  • in reply to dixonselvan

    Dixon,

     

    Thank you for the kind words and seasons greetings.  I hope that your work demands lessen a bit and you are able to keep on track to build some fun projects.

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