Robotic Palm (wierd version)

Hye LMR peoples!

It has been long time from my last robotic upload on this beloved and motivated web/blog. I have work with lots of project for other people. But this freaking long thumb robotic palm project take most of my time, so it is worth for me to share with you.

The Objective is to animated the fingers movement to mimic the alphabet sign language by human hand.

And it is look easy for this 3 alphabet! Yeay. And start to build. First I came out with the fingers mechanic. Thinking to use all the available material around me, then design below come into my small brain.

In Malaysia,we don't have much luxury in obtaining custom raw material or special screw. And the standard mechanical structure sell here are VERY EXPANSIVE, 4-5 times price compare to directly order from China. So the material list for fingers are :

PVC pipe, rubber band, Super-holy-powerful-glue,nuts and screws,connector block,and plastic signboard and string.

And I love this plastic sign board. I get it for RM2(~0.7USD) as the main raw material. So he need to suffer from my cutting tool.

I'm have fabricate the modified version of  'arduino pro mini' becoming 12 channel servo control. I have mistakenly buy the Atmega168x, 'x' cause the IC ID verification by original Arduino IDE failure.  So I have change the arduino-1.0.4\hardware\arduino\board.txt to one that compatible with Atmega168x version.

This 'customuino board' using I2C interface and connected to basic PIC18F4550 board which having USB communication with PC. Simple VC++ GUI was design to talk with this PIC18 guy and send command on how the fingers are working.

PROBLEM FACING AND SOLVED

Eventhough I used seperate power for 6 servo and 2 ucontrollers, there are still some noise issue that causing the uC mulfunction which caused the USB communication and servo driver to halt. Capacitor (i used 10uF) was put near to the PIC VCC is very important. Additional I have put a diode across the VCC to make sure no/less effect of back EMF go into the uController. This is happen because I'm to lazy to add protection to my system and I'm debugging this for few days. that a lesson learn.

SUPER PROBLEM

After feel happily ever after, I start tuning my code to make sure GUI are properly comparing the alphebet input key-in by user and send a proper movement setup to the 'robot'. Its start with alphabet 'A'....its been very hapy to do this until I found THIS!

Mother of cat! It is not possible with my 'handicap robotic palm' to do this. (T^T). Then I said to myself, "NEXT TIME, NEXT TIME". That the story about this noob robotic hand.

VIDEO READY.

You can see on the early video, sometimes the finger is twitching like human. * Actually that is not good. =p

So this should be the preview of my humble palm robot.