Ideas for mods

[Bård Ove Myhr]

Planning to build the Vorpal with my son for Christmas. Just hoping all the parts get her in time...

Thanks Steve for making this possible, it is such a great project with a lot of educational value.

Even before starting building we have been thinking of possible mods. We would like to hear your thoughts on them and if they would be technically feasible... 

Maybe it is more like ideas for Vorpal v2, I am not sure, but I would like to throw it out there to hear what the community thinks. 

The animated eyes

The bots of Alonso Martinez presented on Tested is very fascinating,  especially the emotional feeling and expressions they expose.

https://www.youtube.com/watch?v=0vfuOW1tsX0&t=188s

So a mod in this directions would be very fun to do and I also think this would add a lot of value and interest for the project. 

This might be an advanced mod though. 

The mod would be done with either an add on (on the aux port) or more permanently by redesigning the head and adding it inside the top dome, showing the eyes through two eye holes.

The eyes would be done with oled displayes connected to the nano through i2c. These oleds can usually be modified to two different addresses so two displays can be controlled on the same bus. A new almost square one is out 64x48 pix, 0.66 inch. seems to be the right size. Either it could be just fitted behind a hole in the top dome showing the animated eyes. Or do as Alonso did, putting acrylic lenses/domes on top of the displays. The lenses would probably distort the visibility of the animation so if the goal is advanced animations the lenses should have very little distortion, or with only blinking (like Alonsos) more distortion would be okey.

The animations could be automatic adapting to the movements and/or they could also be controllable. through the matrix, somehow. From my own testing oled displays takes a bit time for communication, and I have seen fast stepper controls suffer from display updating, but with servos this might be less of a problem. Anyway, I doubt advanced animations would happen at same time as movements, so it should work.

The eyes could be inverse black on white background like human eyes giving it a more human feel, this allows for more movements; looking right - left, etc. staring, etc. 

The mentioned OLED can be found here. Approx 10 eur for 2x. Be aware there is a 3.3v version as well, so make sure to get the 5v version.
https://www.aliexpress.com/item/White-0-66-inch-OLED-Display-Module-64x48-0-66-LCD-Screen-IIC-I2C-for/32779913349.html

The display is 0.66 inch which should translate to approx 14x11mm, so lenses with diameter 11mm  might be optimal:
https://www.aliexpress.com/item/1W-3W-5W-LED-lens-diameter-11mm-Double-Convex-lens-led-optical-lens-Laser-light-lenses/1711559730.html

Head movements

Another user here mentioned a rotating turret and similar to Alonso's bot a moving head could add to the eye animations. His bots had very advanced movements, but even just a 45 degree to each side movement done with a simple servo rotating the head (need a double shell solution) could add a lot to the emotions Vorpal could express together with eye movements.

Maybe this is way too advanced for this project, but I think this will add a lot of emotions to Vorpals look and many children would probably connect more with it if it had this kind of emotions.

The best way could be redesigning the top dome for this, but a simple hack would be to make it as a magnetic add-on connecting to the i2c bus through the accessory port. Adding wires for i2c needs to be done.

Firmware updateable over the air

I haven't tested the Bluetooth modules with android, but if I understand correctly there are modules that are a little more expensive and allows for programming the Arduino over the Bluetooth. it might not be important for the casual user, but for those who really like to dig into the programming of the vorpal it might be a nice option, that is if it is compatible. Great to have the current module as standard as not to add cost if not necessary. The upgraded modules also allow for programming from devices without USB as an iPad which is great for kids not having access to a normal computer.

Analog Joystick

The current D-pad is button oriented, that is either it is pushed or it is not pushed. This creates a bit hard movements. You can change mode to change walking style but that is it. With an analog joystick, the Arduino would read the amount of movement and could translate this to different speeds based on how much you press the stick in a direction. This would involve redesigning the controller quite a bit but could be done with an insert panel and avoiding reprinting the whole controller. The firmware must be rewritten and reprogrammed though, both for the bot and for the controller. The protocol needs to be adapted to add the possibility for a more flexible speed. These analog joysticks can be found quite cheap as well, and only takes two analog ports+a digital port for the push button (pushing the stick down). The project is just out so maybe this is too much of a change at the moment, but wanted to put it out there...

Example:
https://www.aliexpress.com/item/Free-Shipping-JoyStick-Breakout-Module-Shield-for-PS2-Joystick-Game-Controller-For-Arduino-Hot-Worldwide/32344305302.html

Love to hear from the community what you think of these ideas. Are they technically feasible, are they cool and fun mods, or are they too expensive and difficult?

[Steve Pendergrast]

Hello,

Those all sound like great mods, a few comments:

1. Animated eyes.  I actually ordered some oleds and will be playing with that concept and making sure it all works with the rest of the software. It's I2c so should be fine. Feel free to work on your own experiments!  We could add scratch blocks to control the eyes, or directly write to the oleds in some way.

2. Head movements. I know one person who posted a make on thingiverse already made a "turret" style cap with a pixie camera on it! So this is quite do-able. His design separated the cap into two pieces, one covered the battery, the other had the motor and could turn.

3. OTA updates. Well our scratch feature already does owrk over the air but I think you're talking about the arduino firmware on the robot. I would have to say that for me this is a much lower priority because its not like I update the firmware every day. But if some teacher wanted students to program directly using arduino instead of scratch I do see the value.  I know you need a bt module with programmable pins that can be used to pull DTR low to put the arduino into programming mode. I did stuff like this years ago so I am familiar with it. But there's a lot of little details to make it work.

4. Analog joystick.  I actually had an early prototype that used inexpensive joystick modules and I abandoned them because little kids (and even adults) would constantly break them.  They think that pushing harder makes the robot move faster so they lean in on the joystick as hard as they can, and they just don't hold up very well.  Buttons also can break if you push them hard enough for a long enough time, but they tend to hold up better.  Note that extensive changes would have to be made to the walking gaits to support the joystick, you'd have to move the left side legs a different amount than the right side legs, etc.

[Bård Ove Myhr]

Thanks for the feedback. My dices are on the eyes as well, will keep you up to date on it. Still, need to get the parts and vorpal it self built fiirst.

I havent looked at the scratch yet, but integrating eyes with scratch sounds like an awesome idea. Let kids have a go at creating or using expressions.

Very curious about the "turret" mod, couldnt find it. Do you have a link?

Have a nice weekend!

B

[Steve Pendergrast]

It was just a photo posted as a "Make" on the thingiverse page for the hexapod project.