Thread: Use the Prop-SX with VSA

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After several requests from customers (who seem to be building their own talking skulls) I have written programs that allow the Prop-SX to be used as an output device with VSA. At the moment I have three programs:

1) 8 servos + 8 digital outputs
2) 8 servos + 8 pwm outputs
3) 16 servos

With the Prop-SX all you have to do is select the program that you want, download it, then connect your PC to the Prop-SX DB-9 connector for control. The Prop-SX has high-current drivers so you can use those outputs with programs 1 and 2 to run things like relays and valves or LED spot lights.

You can find the programs in our user forums:
-- http://www.efx-tek.com/php/smf/index.php?board=16.0

All programs are written in SX/B (free compiler from Parallax) so those of you who are adventurous can hack away.

I'm just now in the research stage of building some talking skulls actually...

Just a couple questions:

1. What advantage is there to using the Prop-SX as to the servo controller board from you guys?
2 Does it not perform the same functions?
3. Does the VSA software work with the servo controller?
4. If i did use this board could i use the VSA AND use remaining outputs to control other loads such as LEDS etc etc... ?

I think thats it for now THanks!!

1. See #4
2. Yes, and more. It can do only servos (16), servos (8) + digital outputs (8), or servos (8) + PWM (8) outputs (for LED fading, etc.)
3. Yes, VSA works with many off-the-shelf servo controllers; we wrote a program to be compatible with one of its built-in protocols.
4. That is exactly the point; this is why we did it (and why we were requested to do it).

Since the Prop-SX is a programmable controller it can do what you want it to do -- servo controllers are just that, and most cannot be re-purposed (not easily, anyway) should you desire. Let's say you get bored with you skull and decide to do something that involves a lot of pneumatics; the Prop-SX can handle that new chore. Or if you want to put you talking skull in the middle of a heavy pneumatic prop you can, as one of the programs drives eight servos and eight digital outputs; the digital outputs could be LEDs, or they could be valves for your cylinders (the Prop-SX has ULN2803s on-board so it can directly driver relays and valves).

Wouldnt a routine consisting of 8 servos seriously limit the possible length? Ive just heard this about the prop-1 controller. I might be combining an animatronic skull with my pneumatic monster so if I dont plan on strictly controlling it with VSA this might be a good option

Sorry if I wasn't clear. The Prop-SX is not storing the routine, it is accepting on-the-fly commands from VSA (that is also playing the audio) and responding to them. The idea is that with the Prop-SX you can drive servos and solenoids (or dimmable LEDs) at the same time - again, from VSA.

The Prop-SX has a 32K EEPROM on board that we're not presently using. One thought is to be able to export the VSA show to a format that can be dumped into this EEPROM so that you show can run unplugged from the PC. That will take some time to develop, and it is our intention to do so

As a maker of a dedicated servo boards I think your idea that they cannot drive relays and pneumatics is wrong on several fronts. The first is that there are many relays, dimmers and other device drivers that accept servo PWM codes that can be plugged in directly. Second, our board is DMX and there are more devices that are dmx compatible than any other protocol. (ok, I made that up but it is probably true). Last, our board uses the same Cypress chip that the Parallax board uses and is completely reprogrammable by anyone with the skills to do it (not me). So you could use any of the 16 pins available as either inputs or outputs, just as with the prop board. Frankly, that seems the hard way though to accomplish what already available dmx devices do quite nicely.
And also - VSA can drive multiple devices at the same time. So you could have a BOC controller and prop board in the same routine.
Jerry Jewell
SkullTroniX
916 600 2295

I'd love to see a servo-compatible relay -- do you have a link? Now, if you mean a board that will interpret a TTL servo signal and convert it to a relay drive output then we're on the same page; again, the Prop-SX has headers to drive servos and the output buffers (ULN2803) to drive relays, valves, lamps, etc.; it's all built right in and completely customizable.

I don't know that DMX is the most used protocol, but I absolutely agree with you that it's popular -- we support it too. At Transworld we'll show-off our RS-485/DMX board that we developed with a major amusement/entertainment company. Frankly, they were tired of paying $500 for two channels of DMX relay control (that's the rub with DMX, it tends to be pricey), and huge consulting fees if they needed something custom. At 10x (this company always buys in volume) the Prop-SX plus DMX board is about $105 -- this gives them eight channels of fully customizable control (and we don't charge for programming assistance). Thus far I've written programs for the Prop-SX in DMX mode for relays (standard digital outputs), PWM of outputs (for LED lighting control), and for servos, so this means a DMX-compatible Prop-SX could play nicely with the BoC -- everyone benefits.

I'm not sure it's fair to say that the Cypress PSoC is user-reprogrammable, not in the haunt industry, anyway. It takes about $1000 in development software and as you know, it's not an easy device to configure and program -- we know this because my business partner developed the Parallax Servo Controller (PSC) when we were there. The SX, on the other hand, is a really simple microcontroller and the development tools cost totals about $50 (for the SX-Key, the programming software is free and even includes a nice, PBASIC-like compiler called SX/B [we use it a lot]). And with fantastic web resources like the Parallax SX forum and www.sxlist.com it's a great starter for those that need a little more power than what the BASIC Stamp has to offer.

I didn't mean to suggest that the Prop-SX is the answer for VSA hardware output, just another possible answer in a field of good ones. Many have been asking us to provide VSA compatibility and that's all we've done.

I use ULN2803 Darlington Arrays quite extensively, they are an impressive IC, however, Ive found them easy to blow, I dont reccomend them for driving anything but relays or circuits under your control, if you pass their 0.5A per channel limit they blow very quickly, solenoid valves can easilly blow a ULN.

The PWM relays Jerry refers to are like below, early revs of the Skull had something like this but the BoC no longer needs it.

http://www.technobots.co.uk/cgi-bin/...20#a3400_2d020

DMX being expensive is another popular myth, a USB dmx converter starts at $50, if you read my other post comparing the BoC with a PSC you will see its actually a very reasonable comparrison in price, the RGB spot lights are about $50, there are a wide variety of relay packs and dimmer units available.... BUT the biggest saving with DMX is time, simplicity and SPEED, Ive programmed serial devices for 20 years, and was amazed at the speed of DMX.

Maybe you should have a chat with us about VSA output at Transworld, Reading a VSA file (actual file not export) and squirting it down a serial link is actually quite easy, we already have a native VSA exporting function in our Motion Capture system.

You're right, Phoenix, the ULN can be blown if you run it out of spec, so we provide guidance to our customers so that they don't. And if that does happen, which we anticipated (we've been doing this a while, too), the ULN is in a socket and can be replaced by the customer -- there is nothing more irritating than to have to send a product back to a vendor for a simple repair.

I absolutely agree: DMX is fast and can be very useful -- that's why we responded when our customers asked for it. My comment relative to price had to do with the haunt industry which is very cost-conscious; we know this is a fact: we're one of the lowest-cost vendors in the business and we're still asked for deeper discounts. Human nature, I guess.

Scary:

I spoke with KC (Vixen's creator) this week and he is creating a Vixen driver for the MiniSSC protocol that VSA uses as one of its standards, and that we used in the Prop-SX programs I wrote for VSA compatibility. This will let Vixen users run that code, too. Both programs have strong user bases and our goal, of course, is to provide another hardware device for them; we think using something like the Prop-SX that can drive servos and solenoids from the same board has merit.

I appreciate your kind comments; we really like building programmable controllers and showing our friends how to make them do nearly anything they want. Like you, given all the money in the world I would still be custom-building (or at least, custom coding) my own projects.