I need help with the $50 robot

[thebrakshow5965]

OK i'm using the 4.8v battery holder can anyone send me a picture of how the 4.8v battery holder and the 9v battery hooks up to the circuit board? I am so confused on this because of the part were the instructions said to remove the connection if you were not using the 6v battery holder. thanks! or at least explain it a bit better.

[Admin]

I don't have a picture of it, but here is the concept . . .

Connect the - ends on both batteries together for a common ground. All grounds connect.

Then connect the + of the 4.8V battery ONLY to where the servos plug in, middle row of the headers.

And lastly connect the + of the 9V battery ONLY to the voltage regulator input. The voltage regulator output goes the the microcontroller and sensors only.

Make sure the + of the 9V and the 4.8V do not connect.

I know this isnt a detailed wire by wire step by step instruction, but its the idea so if you think about it for a bit it should come to you.

(if still not, let us know)

[thebrakshow5965]

ok look at this and tell me if its correct.

[thebrakshow5965]

does that picture look right to anyone?!

[Admin]

Yeap this is correct . . .

Except the yellow arrow is called ground, not -9V and -4.8V

(took me a while to figure out where your arrows were pointing and what that yellow arrow was . . .)

Make sure nothing over heats when you plug stuff in, just in case . . . And do a voltage meter check if you have one, too.

[thebrakshow5965]

ok i hooked up the power. one last thing the L.E.D. isn't coming on ( the servos are hooked up but i haven't yet made my sensors ) is that a problem or does it not come on until i program it??? sorry I'm just so new to this 

[Admin]

It wont come on till programmed.

(you can control the LED in software)

[thebrakshow5965]

ok I'm on the programming part and i am using the serial programmer. now i've doen everything but when i come to the ponyprog i get '--Communication port not available (-16)--  i have no clue what that means

[Admin]

Things to check:
is it plugged in
is it turned on (check the voltages to make sure)
are you using the correct com port?

[garriwilson]

One more thing I believe:

Is your 9v battery ON? Or battery pack?

[thebrakshow5965]

ok I'm stuck again. on the servo mod - you have to open it up take the main gear off and the little ones start spinning really fast then you have to turn the little nob thing until they completely stop and glue it there right? ok i did that and took off the stopper, also I had to strip off the inner part of the big gear (it was plastic and you could not take it out like in the tutorial) and put it all pack right? now on the tutorial it said to make sure all the gears spun freely after it all was assembled but how could they if i super glued the thing that allows the big gear to spin?? the servo tutorial didn't make much sense because it is shown with a different servo then the one for the 50 dollar robot.

[Admin]

now on the tutorial it said to make sure all the gears spun freely after it all was assembled but how could they if i super glued the thing that allows the big gear to spin??

Normally the big gear is connected to the pot for feedback control. Basically what you are doing is disconnecting the pot from the main gear, so that the main gear can spin and the pot won't. You aren't gluing the gear, you are just gluing the pot in place so it doesn't rotate by accident and mess up your calibration.

[thebrakshow5965]

hmm... is there a better servo i could use for this robot?

[krich]

The problem is that most servos don't spin continuously and that is what you want.  Your other option is to go with a motor, but then you'll need an H-bridge circuit to control forward/reverse which will take more output pins on your AVR.

Really, the cheapest way to go is this particular servo with the mod.  I saw that ServoCity would sell you a continuous model of the same servo for +$20 or something like that, but that defeats the purpose of the "$50 robot", right?

[thebrakshow5965]

ah i see i see. man you guys really help. i freaking love this forum! ill get back at that mod now that i understand it better

[thebrakshow5965]

Just a quick question on the 50 dollar robot. Why does it have extra prongs where the servos go, as well as where the photo resistors are? seems like a waste right?

[Killtacularmods]

are you talking about the 5 sets of 3pin header connectors for the servos? well there's five so you can run up to 5 digital I/O devices like (servos) and theres 6 sets of 3pin headers so you can run up to 6 5v regulated analog devices like (sensor's). How is it a waste? thers extra headers so if you feel like upgrading to a bigger or more advanced robot you can.

[Admin]

Its upgrade space - you can add additional sensors and servos in the future if you'd like.

There are a few more pins I didn't put headers on in the tutorial, so you have even more upgrade space than what you see.