RS-232 Servo controller work as a TTL passthrough?

Support Servo controllers and servos
1

I want to connect the 8 servo, serial controller to the PC using RS-232

This one.

And i want to connect a Micro serial dual motor controller to the Servo controller. The Motor controllers pin 4, to the TTL OUT on the servo controller

Will the servo controller work as a passthrough for TTL?. IE will i be able to control the daisy chained Motor controller from the RS-232 controlled Servo controller?

Or will i be forced to use a RS-232 to TTL converter? (Not using usb, definitely has to be serial).
I’ll use a TTL converter if i absolutely have to, but if i dont, then i dont want to, and it would be cheaper not to.

2

Yes, you can use the serial 8 servo controller as a pass-through, one way RS-232 to TTL converter exactly the way you describe.

-Adam

3

Thank you so much, with this new information, i can get to purchasing my parts and buying my robot.

The combo of these two controllers cost less than a single RC motor controller of my previous layout.
Now i’ll actually have money left over for a bluetooth to serial adapter.

4

Hello,

Your comment about the prices makes me a bit concerned about your motor control requirements. Every RC motor controller I’ve seen can deliver much more power than the motor controller you’ve chosen, so make sure you’re not expecting too much from it. I’d also strongly recommend the qik 2s9v1, which is much better than the micro dual serial motor controller in almost every way.

- Jan

5

Thanks i was looking at that controller as well.
It would still be within my budget as it’s only $1 more.

I’m also on another forums as someone is talking to me about the Lynxmotion SSC-32 servo controller.
I’d prefer to use their servo controller, but i’ve yet to recieve info if it’ll work as a TTL pass through.

The whole Daisy chain thing with a serial motor controller is the only way this will fit into my budget as i cant afford those RC pulse dual motor controllers which i need for a tracked robot platform.

6

You can make a very basic RS-232 level converter with a transistor and two resistors, so that shouldn’t affect your decision too much. Why do you prefer the Lynxmotion servo controller?

- Jan

7

It’s a cost vs features debate going on in my head. I’m still leaning to the Pololu 8 servo controller module, simply for it’s price.
The SSC-32 cost a little more than the 8servo controller, but still less than the Pololu 16 servo controller. I’d rather spend small now, and get my feel for it, than go big. But it too has it’s drawbacks.
Their servo controller offers more features from what i can tell. The Pololu one is very simple, which is what i need, but if i ever decide to get into more advance stuff, i’ll have buy whole new servo AND motor controllers.
I’m limited to 1 Serial port on my PC’s. So my choices are

Pololu 8 Servo Controller ($27) and the Pololu 2s9v1 Motor controller ($24)
OR
SSC-32($40) and two single lane RC motor controllers(2x$20)
Obviously the price difference is huge. But the second offers 32 servos, and RC pulse controled motor controllers which i could use universally.
Where the first only offers 8 servo’s, and the motor controller will only work with a pololu servo controller daisy chain.

Right now i’m trying to plan my servo count. It’s starting to stack up. (i have a handful of micro servo’s i got after i crashed my e-sky electric helicopter, 15 seconds into flight, it was unresponcive and lost control)
So i can make a micro-servo powered robotic arm, strong enough to pick up marbles or stack wooden blocks.

I just don’t get why RC motor controllers are so expensive. double or even tripling the cost of the servo controllers.
I’d love to use the TreX Jr. or Sabertooth 2x5, but both cost $60. So to fit those in my budget, i’d need the cheaper 8 servo controller. But we’re back to square one, Not enough servo controllers for my project. I’ll figure something out, i got another week before i can even place my orders.
Please feel free to help pick out alternative parts, i’m not stengy about brands not one of those brand-fan girl types, i’ll use what ever fits my project/needs the best regardless of brands.
Even if the stuff isn’t Pololu brand, help me create the best solution.
I need to learn to hold back on the babbling.

Edit:
The servo controller to the motor controller, you mentioned to connect the reset. Do i just connect the Reset of the Motor controller to the Reset of the Servo controller?
Not sure how that works out.

8

What is the $20 “single lane RC motor controller”? The other motor controllers you mention (e.g. TReX) can deliver way more power than the small serial motor controller. For comparison, a higher-power version of the qik 2s9v1 costs three times as much. Your listing of these higher-power controllers as comparable makes me concerned that you do not understand the significance of getting a controller that can deliver the current that your motors will draw.

Motor controllers are very different than RC servo controllers in that the motor controllers need a lot of extra electronics to actually drive the motors. The servo controllers just send out signals to the motor controllers that are built into servos (which is why servos cost more than comparable gearmotors).

For the connections you asked about in your edit, yes, just connect the two reset lines to each other. The one on the servo controller will function as an output when you’re connected to the serial port.

In general, it’s difficult to give you complete advice because of the motor current issue. Can you provide some more info about the motors you are considering?

- Jan

9

Thanks for all the help, i’m sure this is becoming tiring, I just don’t want to make another “Fallentine” mistake. I tend to buy stuff that either gets to boring to fast, or it just doesn’t live up to the hype.

Each of the drive motors i’d be using are rated for 600mA max at 5v.
I don’t think needing more powerful controllers will be necessary. And i may upgrade to some 1A motors.

Ok you guys are in line with Arduino it seems, and just so i’m not registering for yet another forums.
What about
robotshop.us/arduino-usb-mic … board.html
AND
robotshop.us/adafruit-motor- … duino.html (I’m fairly good at soldering.)

Along with either a DIY or pololu RS-232 to TTL converter.

Will i be able to attach a Micro 8 Servo Controller up to the arduino duemilinove to expand how many servo’s i can use?
And more importantly, can i control my bot on the fly over serial?

I’m sure i’ll get into more complicated programming eventually, but i need the instant gratification of starting up roborealm or microsoft robotics studio, and within an hour having a robot that moves by WASD.

As for the Single line RC motor controllers.
lynxmotion.com/Product.aspx? … egoryID=10
The voltage limit is a little low, but it’s still what my motors need.

Edit:
Choices, choices choices…
Pololu 8 servo controller and serial motor controller = $52
SSC-32 and 2 RC motor controllers = $80 (ouch)
Arduino Duemilinove + Motor Shield Kit = $40. And possible $20 for pololu micro 8 servo board for future expansions.

If i can command the Arduino on the fly over serial, i’ll get that.
If not, probably the Pololu servo controllers.

The SSC-32 setup is just to expensive.Even if the 2 RC motor controllers together cost $20 less than a Dual Rc motor controller.

Heres the platform i want.
robotshop.us/robotshop-rover … kit-5.html
and the pan/tilt i want.
robotshop.us/lynxmotion-pan- … nium2.html

That’s the only 2 definites i have right now.

Edit: Ok to make the RS-232 to TTL converter i need a 4.7Kohm resister, a 10kohm resister, but what transistor do i need?
What is a Q1 2N2222? I dont even know where to find one. (I should take appart this broken radio i got.)

10

I don’t have any experience with an Arduino, but it should work with our servo controllers. There might be some issues with sharing the serial connections for the servo controller and talking to the PC, so you might want to make sure you have a plan for that before buying something.

Have you considered our Orangutan robot controllers? They should be better than arduinos for making small robots. By the way, once you get into the realm of these programmable controllers, you’re going to have to do a lot more than with something like the serial servo controllers, which just execute serial commands. You’ll have to program both the PC side and the robot side, which gives you a lot more options, but with the options comes more complexity.

By the way, our current servo controllers don’t have any provisions for inputs, so that might be limiting for a PC-based computer since you’d need some other way of connecting sensors to the PC.

I also think building a decent robot in an hour is not likely, but I haven’t played with roborealm or microsoft robotics studio.

- Jan

11

The Arduino and the orangutan are programmed in the same enviroment.

I don’t mind a bit of simple programming.
As long as i can output commands on the computer and have the atmel mega microcontroller obey that command, on the fly, then it’ll work.

I assume i program the microcontroller to perform the same command that the PC would do, and then program to PC to transmit a trigger for the command.
I’ll check arduino threads/forums.

Edit:
Not building a robot in an hour, getting it to move. IE once i open the software, having a couple parts moving within the hour.
Roborealm is nice, you can select your controller’s profile, the pololu 8 servo, as well as the SSC-32 are both included.
It instantly gives you sliders for the servos, speed, min/max, as well as timed/instant, and other settings.
Then you can work on tieing those cammands to keys.

I think i’m just going to go for the arduino, it’s basicly an orangutan without the screen, virtually the orangutan using the atmelt mega 328 chip, which is twice the memory of the atmega 168.

I can’t tell, but is this a serial converter?
robotshop.us/ProductInfo.asp … 77952986a1
If not i’ll just get this robotshop.us/pololu-serial-adapter.html

Edit again:I dont like double posting.
The arduino motor shield is a bit weak at 600mA per motor for up to 4 motors, but they allow you to doubleup and use 2 heads for 1.2A. But i’d have to put a heatsink on it, which is no problemo, Got thermal paste and some ram-sinks for computer graphics card ram. Some high temp hot glue to hold it down.

12

[quote=“Fallentine”]I don’t mind a bit of simple programming.
As long as i can output commands on the computer and have the atmel mega microcontroller obey that command, on the fly, then it’ll work.[/quote]
I’m not sure from your posts what you know; “simple programming” for some people is beyond what others could ever understand. Make sure you look at some code examples and have a bit more specific understanding of what “have the atmel mega microcontroller obey that command” means.

That small board is not an RS-232 level converter.

I’m not sure why you’re talking about the ATmega328 and ATmega168, but in case you weren’t aware, the current Baby Orangutan and Orangutan have the mega328.

- Jan