Let's Make Robots!

SPYRO SpoonTail


Guys this is my(our viz. me and my cousin) second robot based on Oddbot's Quadbot. Must firstly thank DAGU & robotshop.com for providing me all the materials required.

I have to esspecially thank Ignoblegnome and Oddbot for helping me out on this project.

The more I researched the better the robot became. Arduino is really very different from picaxe, so many differences , so many new features and the processing tool makes it a winner when there is a PC to Spider connection.

The development of the robot started on 20th April 2011. Had to tackle one problem after another.

The name SPYRO $ilver £ye was given by my cousin,because of its 4 legs and the SRF05 "eyes". And I liked that name so I kept it.

 

 

First challenge was the assembly (the servo alignment was the trickiest part).

So I got the chassis then was the connecting part.

Which was quite simple after closely examing some other pics of Spider controller in action.

The programming part was quite challenging but finnally got the knack of it.

Then came the problem of connecting a SRF05 to the board, it was the first time I was using the spider board, a SRF05 and Arduino programming software.After troubling so many people with my queries on the same, I finally got it done.

Here is a guide I made just in case you need it.

Finally ended up with this (lot more upgrades to come don't worry! ):

The sensor program worked pretty well so did the entire autonomous program. But I just can't seem to be able to power the whole thing via batteries alone. I tried 6x1.5V AA batteries & 8x1.2V AAA batteries but in vain. When ever I do connect the batteries the bot moves a few steps then resets by itself :(

So for now the program I am using is using an interface between the PC and the Spider via a Serial Monitor. Here is a snapshot of the command list ( using switch..case commands) which I used in the video.

An autonomous version is around the corner. Just wait, but till then keep giving me advices guys :) and do help me making it autonomous.

"The more you know, the more you realize you know nothing"

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I bet this was a lot of work. Looks great! At the moment I got some problems with the ultrasonic rangefinder (URM3.7). I am not sure if it is broken - or just wrong triggered. Do you read PWM or Rx/Tx signals? For your battery problem: I would suggest a second power circuit for the servos. If two servos are moving at the same time it needs too much power = your arduino reboots and then restarts again. Dont forget to connect the grounds of the circuits together. Greets!

For sensors like ultrasound rangefinder, you can just use the PING programs located in Arduino which should work perfectly as long as everything is connected properly, I did make a tutorial on how to connect an SRF05 to a SPIDER board , it may come in handy for. As for the power problem thanks for the tip! its not 2 servos moving at a time, its 8! Will try to do something about it.

Cheers!

Your video is great. When will you have it working on batteries?

It is working on batteries quite well, but the weight of 7x1.2V 2700mAh AA batteries are worrying me.

I will post a video of it after I write my SAT which is on 7th of this month.

I'm glad you sorted out your power problem then.

AA batteries are about as heavy as this chassis will handle. If you look at my video carefully you will see my quadbot curls his legs under him at a 45 degree angle so there is less strain  on the servos.

You should be able to use AAA batteries but your run time will be shorter. Otherwise you can try LiPo batteries.

I had one more simple problem which I am not able to solve, I cannot make the servos and sensors work at the same time, so for now the autonomous program is:

1. Walk 5 steps forward

2. Look (find distance)

3. If distance < 20 cm goto step 1 else goto step 4

4. Walk 3 steps back, turn right

5. Goto step 1

You have not explained the problem. Have you got a conflict with your timers?

Now I got it working, the sensors and servos work together perfectly! And you are right creating a walking motion is really quite difficult, I am trying different things. 

I realised that the bot can walk easily on rough terrain if you just increase the value of time=100 to some time=200.

 

If you look at my code for "Chopsticks" then it might give you some ideas for creating better walking code.

By having the servos in an array and using the switch command to generate a programmable sequence I've found it easy to generate different gaits.

I've recently modified his 4 legged gait to combine forwards, backwards, turning and walking sideways into a single sequence that allows complex movement from just 3 variables: Left speed, Right speed and Strafing speed.

That is a great robot. I am pretty intrested in building a robot similar to this. Two question, is it possible for you to post the program you use to control the robot ( i kinda just got in to robots) and the chassis that you use, can you build that any where or did you make that yourself?  Excellent Job!!!!!