How much would you pay for a robot?

The modern microcontrollers are marvelous! (and unfortunaely, too often

Could you give me a few examples of these micro's? I have used PIC's a little bit but did not realise you could get micros with all that built in. I was tossing up whether to use micros or a PC mobo, thinking that micros were a bit limited. I do like the modular approach though if you are experimenting and trying new things, it kind of makes sense to have a "universal base" and plug on different modules. As long as all modules are designed to communicate with the same protocols.

Matthew

Commercial

Jerry

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It's funny, its like the initials RAID, at first is was "Redundant Array of Inexpensive Disks" then it got corporatized into "Independent" Disks.

I very much remember it being "Consumer."

I agree with you that some popular acronyms seem to evolve over time but I have been working with COTS issues for the military since this term came into being and I have never heard it called anything other than commercial off-the-shelf. Here is a page from the "COTS Journal" that has a definition:

Jerry

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I typed a pretty long reply a few days ago, but deleted it after re-reading it because it was way too negative and not based on personal knowledge. Still, perhaps some of my comments would be feedback you would want. Again, note that this is from a person who hasn't personally done much with robotics.

Over time my price expectations increased... as a novice the idea of a robot kit over $100 was way to much. But, I now see something in the range of $300 acceptable for me.

Still, I realize it is too low a price for what you want to offer. The reason is that I would consider my robotics efforts to be play. It doesn't have a real reason to exist other than my enjoyment. Then if it is for my enjoyment, the act of designing it myself is a large part of the fun. To pay someone else to have my fun is not a good idea.

Joe Dunfee

If the is the prefered meaning of the 'C" is commercial, thaks for the update. I did see "consumer off the shelf" in a few places on google, but you are right, the common usage seems to be "commercial."

I bet I could code in assembly a z80 program that would fit your "real" robot requirement (above), and fit into about 20kilobytes.

:-)

R.

Perhaps you could.

None included, and the cost of one of thos cheap components could get you a better processor with all those features built in.

How much is a module that does Quadrature and PWM? are these PCI? How many such peripherals can you put on your VIA motherboard?

No, I'm not kidding.

Saying you can get the peripherals cheap is not like saying you have the interfaces you need. ;) Might as well buy a bare Hemi engine, which is plenty powerful, because you've heard you can get a trailer hitch and you can hook anything you need to pull up to that.

Matthew, two micros I am particularly focused on these days are

1) DSP56F805's and family 2) LPC2106 and family

(Commercial Disclosure: If you didn't know, we, NMI, sell boards based on these chips. It's hard to separate my commercial life from my personal hobbies because they overlap. I make, or have made, things I like.)

The DSP56F805's are a 80MHz 16-bit DSP based processor especially designed for motion control projects. The internal bus is 40MHz and you get near 40 MIPs. (So it's about 20x the PICs)

Great thing about the DSP56F805's is the hardware provided:

2 quadrature port inputs. 12 PWM outputs 8 12-bit A/D's 16+ GPIO 14 timer pins and 16 timers

All the timers can be multimode and (for instance) generate PWM, so you can directly control 26 RC Servos in hardware. No need for SSR's.

Or the timers can be more quadrature inputs. I've written an app that read 6 channels of quadrature input for position, and used the other timers for pulling velocity off those inputs at the same time.

You can hook a timer to a SRF04 sonar, pulse the sonar, and come back at your leisure and see when the echo pulse arrived because it will capture and store the time for you.

As I say, I'm pretty amazed with these controllers, they make robotics much easier, because there's no processor overhead to run these timer and PWM features. It's all done by the hardware. Set and forget.

On the down side, they have CAN and SPI, but no I2C interface (although it can be bit banged without too mcuh difficulty). These take considerable current ~200mAs (but it's still small compared to a PC). Program space seems sufficient (64K Flash) but RAM is rather limited. (4K RAM). The choices of languages and development support are rather limited. Code Warrior is a professionally priced C environment from Motorola, which often manifests the most amaturish mistakes.

Newer versions are coming out with even more memory and faster operation (56F8365: 120MHz, 512K Flash and 32K RAM, 16 12-bit A/Ds),

The LPC2106 are a 60MHz 32-bit ARM7 based processor. They seem to run about neck and neck with the DSP's, but have larger memory (64K RAM 128K Flash). They have less motor control features, they do have PWMs. No A/D's (but others in the family, ie the LPC2132s, do, but less RAM). They have I2C but no CAN (but others in the family do).

These are lower operating current, less than 100mAs, and less I/O intensive. The appeal of these seem to me to be having enough memory to do some mapping, and the ubiquitous ARM core, with all the development support you could wish for, and then some. GCC being available. And there is no doubt ARMs will be around a while, with a new generation of

200MHz (and higher!) devices just coming out now (some with USB host ports!).

(A new version in this family is coming out that is extremely low price, competes with low-to-mid end PICs) and we hope to offer a $29 board based on it soon.)

Really? A better processor? How do you define "better?"

You can do it cheaply if you are inventive. I'm actually working on something really effective and cheap (

The point I've been trying to make is that mere control of devices is not "robotics." It may be "automation," but "robots" has a strong AI component. The "better" computers you talk about are not better "computers." They may be more suited to device control, but probably less suited to computing in general.

This explains a bit.

Boy, you aren't much fun to talk to.

Isn't this thread about your wanting us to do your commercial research for you, establish pricing, so you can decide if your in business or not? And when a guy with 25 years business experience, and another 15 years electronics experience, tries to tell you the best of what they've learned, when it doesn't agree with what you've already done, you besmirch them.

With the amount of arguing going on, it really looks like you are talking alternately about completely different things, and the same thing without even knowing it.

Do you guys realize that PC's have MCUs and DSPs all over the place -- in network cards, video adaptors, SCSI controllers, etc ? Hell, the mouse and keyboard each have a dedicated controller -- the CPU isn't polling the encoder wheels and individual keystrokes directly. There is a dedicated controller summarizing the information and passing it along the PS/2 or USB buss.

The two platforms are not mutually exclusive. Just about every device connected to the PC has a dedicated microcontroller or DSP of some kind.

Yes, trying to do quadrature and actual control of hardware DIRECTLY from the PC not the optimal way to do it. You can program something like an AVR easily to do it all in real-time, or use one of the dedicated board Randy likes.

But at the next level up, hooking these micros up to a PC then provides an easy to to co-ordinate all the low-level tasks. All of the research papers I've read on sonar mapping, image recognition, etc uses this approach.

So you are BOTH right. :-) Each has it's place in the process.

I definitely agree with one of Randy's original statements: Deciding on the motherboard first is putting the cart before the horse. Build your base and power supply first. Then get some controller working that controls your main wheels. By the time you finish this, I guarantee you another generation or two of PC hardware will have passed, and you will probably have a faster hand-me-down motherboard than the one you would have bought at the outset.

If you have kids -- make that four generations.

"besmirch" :-) reaching a bit in to that thesaurus aren't you? Has anyone really "besmirched" anyone since the late 1800s?

I'm having a duh! moment, my comment "This explains a bit," was not intended to be to "besmirch" your motives. I'm sorry if you took it that way.

It was mean more as an understanding of your perspective. We are all most comfortable with what we are most familiar.

I'm truly sorry if you were hurt by my post.

>

Argue? That is such an ugly word, I like to use "discuss."

Yup.

I have made this point repeatedly, not in so many words, of course.

maybe true, however, a PC and OS which has a proper interrupt servicing infrastructure and buffering counter/timer interface circuitry can do this easily.

I think we are debating the relative merits of the approach. You are basically describing the robot I proposed.

I think this is flawed. The *reason* you decide on the computer system first is to capitalize on standards. You purchase standardized equipment at commodity proces -- PC motherboards, and you can upgrade the robot without redesign.

: I think this is flawed. The *reason* you decide on the computer system first : is to capitalize on standards. You purchase standardized equipment at : commodity proces -- PC motherboards, and you can upgrade the robot without : redesign.

But that's the reason you don't have to buy it first ! Design your motor controller with any standard bus you want -- PCI, rs232, usb, CAN, and it doesn't matter with motherboard you ever choose to use, upgrade, etc.

If you buy the motherboard before building the rest of the bot, the motherboard will be obsolete in it's unopened box before you ever get to use it.

Christopher X. Candreva wrote: [snip]

Which is exactly my point. I can see GREAT reasons to run the latest via motherboard w/ linux and wireless networking on board a robot -- but the ability to do so isn't much of a selling point for a general purpose commercial robotics platform. The mobo and wireless are the easy parts. The hard part is a reliable, expandable, robust platform with decent motion control and plenty of sensors (or at least potential for sensors to be added).

But.... you have to decide *which* type of computer first. Whther it is a Tyan, EPIA, etc who cares? It is the decision on the "type" of computer more importanly the the specific computer.

Now, with many embedded system, the type is the specific computer. With the "PC on wheels" metaphor, you get to choose from a number of specific computers.