Heathkit Hero Jr was made in mid 1980 (85 or 86 I think). I got this one maybe 2005. And long story short...He had a hard life, I found him at a flea market, he had been stored in a barn for at least 20 years, and had small furry creators living in him. Needless to say he was looking pretty bad. After a long time of just cleaning him up, I replaced the batteries only to find out he was failing all of his self tests. Yes he powered on, but that was about it.
Honestly, He sat around my place for a long time before I decided what to do with him. Late 2013 I was introduced to Arduino microcontrollers - I had previously used Parallax's Basic Stamp and the Picaxe before this.
But what Arduino did was made it cheap and easy to build things (robots), So early on I knew what to do. Replace the bad hardware with modern Arduino compatible stuff. - Part of my goal for doing this project was to keep him looking as original as I possible could.
I started the basic build out/replacement sometime in mid 2014, and got to a point that I'd like to think I was finished (mid 2015). It was about this time that a local robotics/electronics club I belong too was asked if we could do something "special" for Star Wars Day that our local library was holding. Star Wars Day was Dec 12, 2015 for them.
And I was asked if Hero Jr could be part of it. So, Hero had some special changes made, and some special effects done just for that day - And here are a few of those pictures and videos.
Currently Hero Jr has 5 Arduino Microcontrollers in him, 2 specialized microcontrollers (MP3 and Speech)
Step 1: Early Video.
So, As I said he currently has 5 Arduino microcontrollers, 4 of those, and the MP3 player was added just for doing the Star Wars day demo seen above. (This demo was shown to the person in charge of the event, it's not even close to the final product)
Other things he has in him currently:
2 L298 Motor Drivers
Ultra Sonic Sensor
Light Sensor (Photo resistor)
8x8 RED LED Matrix
A few 5 volt regulators
A few 12v to 5v
A relay (for switching to charging mode)
2 6v batteries
A real time clock
A 12v DC motor (the original motor that was on him from the 80s)
A 12v stepper (the original stepper that was on him from the 80s)
(He only has one drive wheel, and both the stepper and DC motor are attached to that)
a Hall effect sensor
a SD card reader
Keypad matrix (original)
9 LEDs (mostly original)
It seems like I am missing something, it may come to me later.
Step 2: Getting Some Upgrades
He expressed his desire to be a Jedi - I agreed, so I found a light sword from a local dollar store, put a neopixel strip in it, added some sound effects to the MP3 player, and a Arduino to control it.
Step 3: Next Up....
To cover his ultra sonic and the rectangle opening. I used simple window screen (as in a screen door). It looked great, and best of all it still let the ultra sonic sound pass thou it. Mission completed! -- Or was it??
Step 4: One More Upgrade.
Looking at some pictures of R2D2 I realized he had some LEDs (or light effects) always flashing - I quickly added one more micro controller and a 8x8 LED matrix - The idea was just to have the LEDs flash at random. The controller was independent of the other micro controllers in him. this was done to save time and to not have to re-write code over again.
My LED flashing turned out better than I had hoped behind the black window screen, it really made him pop.
The red really worked well because he kind of has a shade of red on his head. I could not have been happier how this turned out.
Step 5: The Final Demo Video.
With one small exception this was the final - and what was used at Star Wars Day (of course he did have his back cover on during the show.) I had to make a small change to get him facing forward after his dance, but other wise this was it....it had all come down to this moment.
Step 6: Star Wars Day 2015 - West Chester Public Library (Midpointe) Dec 12
Here we are! Look at me - proud parent of a happy little droid.
Step 7: Putting It All Together.
So, I said there were 5 Micro Controllers, and 2 specialized controllers - I never really said how they all worked together to get the job done.... A little magic, a whole lot of timing, and some luck!
There are 2 Arduino Mega - One is for "master" controller, and does most of the communication with the other controllers.
The 2 Mega was in direct control of the MP3 player (which itself is a specialized controller) it also handled triggering a NANO that controlled the light saber.
There were two NANOs - one received a trigger from the MP3 MEGA controller - this was done over serial/ttl
it produced 3 different light effects for the saber (see the video in a previous slide) There is a control line going back to the MEGA that would be set to either a HIGH or a LOW depending on the state of the saber.
The MEGA also had a control line that was set to either a HIGH or LOW depending on the state of the MP3.
This was to help with getting timings right.
The 2nd NANO was connected to a EMIC 2 speech synthesizer - it communicated directly with "master control"
Letting a 2nd controller handle what the speech synthesizer is/was doing really did fix a lot of weird things that were happening, This nano was able to make a educated guess at how long it would take the EMIC to speak. It was set it's control line HIGH or LOW depending on if it was speaking or not.
I love the EMIC 2 synthesizer, but it leaves a bit to be desired as far as control, and when it's done talking. The previous model had a busy line (and that is what I attempted to make by using the 2nd NANO - a Busy line)
Putting the speech all on a 2nd micro controller also freed up the "master controller" to do other things while it was talking (you know kind of like multitasking)
Finally I have an Arduino UNO - this was just for the 8x8 matrix, and didn't communicate with any of the other controllers.
I have all my Star Wars day sketches on github to be shared -
Even if you don't build or retro fit a Hero Jr -there might be something interesting in the code to learn from.
This is a very fun project, and I learned a lot from doing the Star Wars day demos - much of which will stay in the Hero Jr. even thou the original goal of my "Hero Jr retro fit" project was to keep it as original as I could using modern hardward.
Thanks for looking at this instructables.