So I bought an Attacknid off of Amazon after Christmas.  My goal was simple, as I would strip out the electronics and replace them with my own.  I decided to use an Arduino Mega with an Arduino motor shield.  I also added an adafruit ez-link for bluetooth control.  So far it's an obstacle avoidance robot, but eventually I'm going to add an FPV camera and GPS.  

GroG

10 years 3 months ago

Great Project Ghost !

Ahahaha .. he looks very war of the worlds with the big bucket head 

Can you answer these questions ?

  • how many motors do you need to control for the base?
  • what did the previous electronics do ?  What sort of controls did it offer ? Different gates?
  • how much control mechanically do you have over one leg. A quick glance - and the fact that its a "commercial" product would make me believe that the actual motor count is very low - and movement is not done with individual motor control - but is translated mechanically from a fewer set of motors - much like Jamey's design (which manufacturers took from him with little credit)
  • What is working currently?  What isn't and you wish it was?
  • Is BT communication working well ?
  • Do you have video of it walking or obstacle avoiding?

With the ping sensor we should be able to rotate / map its near environment.  It will take a little work - would this be a good goal ?

 I think it would be pretty amazing if it could actually begin to map its environment and begin to interact with that map.

 

 

 

Big shout out to Jamey on this project!  That man is a genius, and I did find his message on the inside of the attacknid when I took it apart, it says "never give up" under the chassis.  To the guts!  It has two 6v motors, one controlling all 6 legs, and the other for 360 degree turning.  The whole thing actually comes in pieces that have 6v barrel plug connectors, controlling the disc shooter, the aiming device, and the head for "battle mode".  The main board is about 2' x 2' and has the motor controller, the rc antenna and the main chip.  The head has a board on it for "battle mode" also.  The whole things pretty much comes apart to leave just the base which you see in the picture.  All I did was strip out the plugs the main board and detached everything from the motors.  I left the two 6v motors and the used the battery box that's attached.  The only thing I added other than my own wires, were 2 ceramic capacitors to the motor leads.  Supposed to clean up the line noise.  At the moment it's pretty much doing what I wanted up to a point.  The standard obstacle avoidance with the ping sensor I'm trying to make alot better than what I've already done with it.  Mapping the environment around it is one of the things I was thinking of doing with the gps and the ping.  I haven't figured out exactly how yet, but I'm working on it.  Bluetooth is great!  I get a nice 115200 baud serial connection up to about 30 feet with it.  I've been playing with a half control, half obstacle avoidance system just for fun.  Later I want MRL making the decisions for the robot.  Also, power.  Any suggestions on a better and lighter way to power this thing would be awesome.  

Hobby Lithium Ion batteries have some of the highest power densities - (power per mass) - they come in all shapes, sizes, current capacity and voltages..

- only drawback would be if you don't have a hobby charger you'd need to get one.

 

So your controlling it from your pc now ?   With what program?  Python?
We could try to control through MRL currently if you'd like .. would be a good first step.

It would basically mean start up MRL - start an Arduino service (the Arduino Mega would need to previously load MRLComm.ino) - connect the Arduino service over the bluetooth COM port on the computer - use the PWM (I assume the motors controller/bridges are connected to pwm pins? - is it a nice 2 bit 1 bit control 1 bit pwm or a naughty 2 bit 1 bit each with pwm controller?)

I may end up getting one of those RC hobby batteries, or possibly some CR123A's but I don't know what the reliability of those are yet.  Currently I'm controlling the thing with serial inputs from just my keyboard.  "I" is forward, "K" is backward, and so on.  I use Putty to connect to it.  The motor shield I'm using is the regular Arduino Motor shield with an L298P, and yeah PWM's are digital 3, and 11, and braking to halt the motors instead of cutting power and letting them slow down.