ServoPod General Question

[lballaty]

Hello,

I'm just beginning to take a look at ServoPod and considering it for a robotics project ...

I'm new to microcontrollers and electronics and I am not a programmer beyond some shell scripting.

My question is ... If I want to start off with a basic robotics project that will move (I'm assuming only 4 servos at this point) and react based on some input from sensors such as sonar, infrared, sounds etc...

Are the hardware/software resources on the servopod enough for me to do that .. It seems from the specs that hardwarewise I should have more than enough on the board ....

But software-wise do I need anything beyond IsoMax in terms of programing language, which I think is the only one embedded at the moment right?

Do I need to add small C?

What about Forth ... what does that get me that IsoMax does not provide?

I know these are real general but I don't know enough about it yet to be more specific

[Dave]

On our Download page are a number of examples of running different devices. It is preferrable for you to only attempt to use one language to program in to make your robot work. From
http://www.newmicros.com/store/product_details/download.html
there is example code for an 18 servo hexapod robot ( with 2 more servos for a pan and tilt head ) H3 Walker.
Also in the examples is the Mark III coder for a minisumo robot that reads a couple of line sensors and a couple of range sensors. We also have example code for reading sonars. And the PID controls shows some dual motor control. So with IsoMax, you also have MaxForth to work with to accomplish your task.
If trying for Small C, I believe there is also some additianl resources showing examples. Currently Small C cannot mix with IsoMax.

[nmitech]

lballaty, Depends on number of input/output requires for your sensors, sound, infrared, etc... I think MiniPod(TM) has enough I/Os, and Analog inputs, and more PWM channels than for your application requires. It may save you some $$$ there.

[lballaty]

Originally posted by Dave

there is example code for an 18 servo hexapod robot ( with 2 more servos for a pan and tilt head ) H3 Walker.
Also in the examples is the Mark III coder for a minisumo robot that reads a couple of line sensors and a couple of range sensors. We also have example code for reading sonars. And the PID controls shows some dual motor control. So with IsoMax, you also have MaxForth to work with to accomplish your task.



So is Forth a part of the IsoMax then ? Another words is the procedural part of IsoMax really MaxForth?

Or am I mixing apples and oranges here?

I've been looking at the samples trying to make sense of them...

but of course I have no way to try them at the moment... maybe soon ...

[nmitech]

So is Forth a part of the IsoMax then ? Another words is the procedural part of IsoMax really MaxForth?
Yes, You are absolutely correct!

[lballaty]

Originally posted by Dave

Also in the examples is the Mark III coder for a minisumo robot that reads a couple of line sensors and a couple of range sensors.


Does anyone know where I may get the Mark III kit with a servoPod?

I'm only finding it on the web sold with the OOPIC

thanks

L

[petegray]

L,

why not buy the MarkIII Chassis kit for $10 ...

http://www.junun.org/MarkIII/Info.jsp?item=2

... add servos, wheels and the Pod of your choice?

-Pete.

[lballaty]

Originally posted by petegray
L,

why not buy the MarkIII Chassis kit for $10 ...

http://www.junun.org/MarkIII/Info.jsp?item=2

... add servos, wheels and the Pod of your choice?

-Pete.

super

thanks for the tip ... which pod will fit on the Mark III .... will the servo pod?

Assuming I would like some space to fool with various accessories like sensors what would you suggest I order to go on top of the Mark III?

Should I get some kind of prototyping board or something like that?

or is that not necessary?

[petegray]

Well, I've had a MiniPod and an IsoPod on top of my Sumo, but the real answer about "which Pod?" - for you - would depend upon your design. You can always look at the chassis and board drawings to check the physical dimensions.

All of the Pods have a huge number of I/O modules, so any of them will probably be able to cope with whatever sensors you fit to your Sumo. Having said that, it sometimes makes more sense to buy the one packing the biggest punch - so that you can use it on your *next* project.

On the other hand, you might want to have more than one Pod, so you can experiment with various forms of inter-Pod communication and so you can have more than one project "active" at any one time.

Regarding prototype boards, they're a good idea - particularly for experimentation and "pre-production" designs. I have a few on my workbench which often come in handy.

Having said that, I can't think of a reason why you'd need one attached to your Sumo - you could always just make your own cables and connectors (and NMI will sell you a very nice kit to do just that).

What sensors you attach to your Sumo will depend - like all robots - upon what you'd like the robot to do. In any case, it never hurts to have a variety of sensors on hand.

One last word of wisdom - once you've bought a few sensors and servos etc, you'll find that many of them come with "extras" - nuts, bolts, brackets, etc. Keep these, as you can often fabricate sensor mounts and other things for your *next* project.

Sorry for the long post. Hope it helps,
-Pete.
p.s. If you don't have one, I recommend buying a digital multimeter too.

[lballaty]

Originally posted by petegray

p.s. If you don't have one, I recommend buying a digital multimeter too.

Thanks for alls the tips I do appreciate it.... I like the idea of having more than one pod to play with the interaction etc...

I realize that for the first project probably any of these would do ... but I would like to be able to expand without having to immediately purchase higher capacity pods.

It seems that I will need controller/adaptor boards for all the pods except the ServoPod and the MiniPod in order to run the servos (control them) and supply the power .... Am I reading that right?

I've been looking at the comparison matrix ....

How many connectors and PWM outputs are actually required to ocntroll and supply power for one RC-Servo Motor

So the number of servos is really limited by the PWM ports in this case?


Also:

can anyone recommend a soldering iron/setup ... I've never soldered anything in my life and would like to purchase something that will last and be appropriate for these tiny electronic parts...

I assume it should be temperature controlled ?

I see a wide range in prices ... what can I look for in terms of must have functionality for this type of project?

[nmitech]

It seems that I will need controller/adaptor boards for all the pods except the ServoPod and the MiniPod in order to run the servos (control them) and supply the power .... Am I reading that right?
Yes. ServoPod, IsoPodX, and MiniPod have header pin connector(s) to allow the RC-Servo wires plug-in direct without the need of soldering, and/or flying wires. Also a seperate power supply to power the Servos is required.


How many connectors and PWM outputs are actually required to ocntroll and supply power for one RC-Servo Motor
The standard RC-Servo has three wires: Signal, Power,Ground. So one PWM signal requires for each RC-Servo.

So the number of servos is really limited by the PWM ports in this case?
That is correct! Keep in mind, you can also use Timers, and I/O ports to generate PWM signals. On the ServoPod, and IsoPodX just for the PWMs & Timers alone, each can handle up to 26 RC-Servos where MiniPod can do 12 RC-servos.

[lballaty]

Well, I've ordered the Mark III as you suggested ....

I've decided to go with the servopod to begin with

I'm sure you'll be hearing from me soon ....

thanks for the help

:)