Armortek

Hi all,

I've eventually got around to posting a basic How-To for the Pololu range of Maestro controller cards. You'll need the software and drivers available free from the Pololu website.

I don't profess to be an expert with these cards so if anyone has any input regarding their experience then please jump in. Similarly if you require further explanation on any or all of this thread then post your questions and I will do my best to help.

Once I've finished programming the latest figures that these screenshots were taken from I will share the file in case anyone wishes to use it.

Cheers,
Sym.

List down for Part 2...

I was looking forward to this. Will start testing shortly. Thanks.

Hi Sym,

I followed this processes from Sym, and got some tips from a professional I know, one thing he pointed out to me, some moves are better made together in one frame, i.e. binocular arm down, head turn, this then leads to the next frame for the body turn in the same direction as the head. I was told, if in doubt go through the moves using your own body, and you will notice that when you turn, your head always leads. This lead to what I think is the smooth programming of my tank commander.

http://www.youtube.com/watch?v=NhKA3saGw6s

hope this helps.

Paul.

Hi Paul,

Some good tips there, much appreciated. I'm glad you chipped in as I was very impressed with your finished figure.

One of the moves I like is to turn the base one direction with the head moving the opposite, in essence the head keeps tracking forward while the body turns. Then on your next frame swing the head around to match the body.

Also if you have 2 frames with different servos on each try setting the duration for each frame to a low value, say 500ms. This will give an overlap of movements that will give a more fluid look to your animatronics.

Keep the ideas coming.

Cheers,
Sym.

Another point worth mentioning is that of end points. The program has preset values of 995 and 2000, these aren't maximum throws.

While setting up the binocular arm on a figure I was struggling to get maximum movement due to a thick leather coat over the joints. I shortened the servo horn to increase torque through leverage but found the servo throw was now insufficient.

By making the lower value 60 and the higher value 2400 I now had all the throw I needed with increased power to overcome that ******* jacket!

Be sure that you only use enough throw to do the job as pushing a servo past its recommended end points can cause problems. Obviously any buzzing is going to put the servo under undue stress and increase load.

Cheers,
Sym.

Hi Sim
Can these boards be programmed from a Mac?

Derek

Hi Derek,

The answer is maybe.

I found this post on the Pololu forum about using the control centre on a Mac, have a read and make your own mind up! It seems the main problem is the ports...

http://forum.pololu.com/viewtopic.php?f ... 99&start=0

Cheers,
Sym.

Hi Sym,

Received the Polulu board this week and started fiddling with it. Your tutorial is great but I still have some questions. When programming I have to servo's attached but they don't work. I guess they need external power to operate them. On the bottom of the board is a so called shorting block(blue) It's pinned now on the far left pin. So that leaves three pins. The two on the right are for battery power to supply power to the servo's. Do I need to move the shorting block on pin to the right, or just leave it there and connect the servo battery? I don't want to experiment here. Hope you can sort this out for me. Once programmed, how do turn it on. Just connect the battery power? Message directed to Sym, but anyone else with the answer at hand is free to reply...

Hi Marcel,

I know we've already talked about this on PM's, but for the sake of anyone else with the same problem I will explain.

The Pololu cards require 2 power supplies to work, one for the card itself and the other for the servos. On the Maestro 12 and above you have the bridging block that allows a single battery to power everything, the Maestro Mini 6 is a little different requiring a bridging wire between the two.

You will find that unless you use either the bridge block or wire you will need a 2 batteries or power supplies to operate the card once the USB is disconnected. Once you have bridged the card you will still need to attach a battery during programming but the card will work independantly on one power source once the USB is removed. I hope this makes sense!

Once you've programmed your card and uploaded the script (under the script tab) the card is ready to use. After it has been bridged for use with a single power supply you can either use a 4.8-6V battery, or use a Ubec like we do to reduce your tanks 12V batteries down to 6VDC.

Cheers,
Sym.

Part 2...

Well that's pretty much it, your card should now be working independently from the PC. The controller requires a voltage that suits your servos, I personally use a Ubec that converts one of the tanks 12V batteries down to 5VDC. It is common for the servos to cause interference due to their close proximity, usually the main neck servo makes the arms jump when moved. This can be easily cured by using ferrite rings, more about these later when I shall cover wiring and final hardware setup.

Sym
Many thanks for fixing/reposting the images in this thread. I know this will be a great help to me, but this “how to” will also help others i’m sure.
Regards
Kevin

Your welcome Kev, unfortunately there's a 10 image limit to each post so I had to split it in two.