Let's Make Robots!

Wall-e MkII/Project 2: The master plans

Howdy all


As i right this i am basking in the glory of getting the final submission of my degree submitted for this semester.

The content: rushed, sub-par and generally shite, however it was submitted at 15:59 (one minute to spare).

This is a monumental occasion - While i'll probably have to resubmit them over the Summer months on paper I am now free to resume my tinkering!

I am writing this mainly to summarise my current states on my projects, and how i am hoping to progress...


Wall-e MkII

Walle MkI is still being repaired; one of the motors has sought early retirement and stopped working. Investigation into that, plus some rewiring, and it'll be back to it's normal self with the help of Ian, my brilliantly skilled help through my first foray into electronics.

However I am hoping to work on the improved revision of Wall-e, and parts are starting to arrive. The plan of attack:

  • Motor relocation - awaiting new, geared motors. No Meccano this time - they will be mounted on the underside directly to the track wheels!
  • battery power - the 4 x 3.7v, 5000mAh, Li-ions (in series) will replace the 2 x paralleled 9v batteries.
  • Recharging the new 14.4v lump will require a circuit to handle this - research to be continued
  • Custom ATMega328 controller - this part of the plan has undergone many revisions. MkI ran on an Uno with motorshield; I first was going to replace it with a Nano and a dual motor driver module. I have now settled on (and ordered) an ATMega328P (complete with Crystal and a few caps), and an L293D motor driver chip, and I'm working on creating my own controller board. I am hoping to fit thise little board (complete with Servo, Bluetooth, SD card, Sensor breakouts) within the battery compartment on the back of Wall-e.
  • SD Card Module - this will replace the use of the original PCB; I will add my own sounds to Wall-e for triggering this way
  • 3 Servos to be fitted - Possibly 2 servo/1microservo dsepending on space. These will be for arm and head movement.
  • Extras - If i have the pins i may add a ping sensor or maybe an IR LED/receiver for TV control.


Project 2

After Wall-e MkII is up and away I am looking to work on a Raspberry Pi-based robot. The concept stands as:

  • Raspberry Pi Brain - this will serve up a Web page as a controller (if not capable of acting as it's own access point i have a tiny little Wifi Router/Hub/repeater to work with port forwarding etc. Looking at Tornado to operate the web server aspect, and I2c to communicate with the bot's other areas.
  • Arduino to control motors/sensors - Looking at an Uno and motorshield combo, driving two beefy motors (for tracks), plus some ping sensors and suchlike on broken-out Analog pins
  • Swappable 'Pods'
  • Up to 3 hotswappable bays for connecting bespoke pods to the bot. Each pod will contain a microcontroller (ATTiny85, ATMega etc - wresearch to be conducted!) This controller will attach to the I2C line on connection (looking at a custom connector to incorporate power to the pod, USB connection to the Pi as well as i2c for maximum possibilities. The RPi will monitor the i2c line to see what is connected, and hopefully display custom controls on ther web pages for those connected.
  • Powered USB hub - to be powered from robot's batter supply.I have a 10-port one to start testing with:
  1. RPi Power
  2. RPi Data
  3. Arduino Uno (to allow the ability to tweak code from onboard the Pi
  4. Wifi dongle
  5. Bluetooth Dongle (may be moved to a bluetooth module attached to the Arduino for conventional RC use)
  6. Pod 1 connection
  7. Pod 2 connection 
  8. Pod 3 connection
  9. Free port
  10. Free port
  • Custom designed chassis - once i have the internal components working i am looking to have a custom chassis and body made for the bot; looking at a wedge shape, with tracks. The pods would be triangular in shape and slide onto the front of the robot and form the hypoteneus of the triangular wedge shape.


Anyway, there's my ramblings - enough to keep me occupied ofver the summer!