ServoPal Discontinued???
erco
Posts: 20,256
Retired, same thing: http://www.parallax.com/StoreSearchResults/tabid/768/txtSearch/servopal/List/0/SortField/4/ProductID/481/Default.aspx
Was I snoozing? When? How? Why? IMO this was a "get out of jail" item for the Stamp, especially the Boebot, to offload servo overhead. I thought BS2s were forever and this would also be an evergreen item to keep the BS2 relevant as consumer expectations grew.
I guess I really should upgrade to the Prop, but I'll be kicking & screaming the whole way.
Was I snoozing? When? How? Why? IMO this was a "get out of jail" item for the Stamp, especially the Boebot, to offload servo overhead. I thought BS2s were forever and this would also be an evergreen item to keep the BS2 relevant as consumer expectations grew.
I guess I really should upgrade to the Prop, but I'll be kicking & screaming the whole way.
Comments
As erco says, it's a huge asset for the BS2 robots.
The BS2 is going to be around for quite a while, why not the ServoPal?
...right there with ya, brother!
With regards to the BS2 versus the Propeller chip. I still find the BS2 much easier to bang out simple stuff on. My current project is on the Propeller and progress is much slower than the BS2. Granted I'm doing more, but everything is just a little bit harder which slows me down.
Hey - whatever happened to the BS2-based quad-copter?
This is a product that we were manufacturing under Parallax Hong Kong. Building in China requires minimum order quantities of 500-1000 units minimum. When our inventory turns of any given product fall too low (a year or more?) it comes up on the Purchasing Manager's radar. She'll do what she can to lower the minimum order quantity, lower the price, and present it to the Marketing Manager who can give her some input. At this point we're probably thinking about it more from a financial perspective than others [like a "get out of jail" accessory for the BS2]. If you asked the engineers or tech support, they'd do some serious hand-wringing and objection to any kind of EOL, the same way you do. It becomes a question of allocating financial resources in inventory, and getting your full return back in a year, or putting that money towards other demands in our business.
There's a good chance that this product had an inventory turnover that was too low for the minimum order quantity, causing us to hold inventory for a long time. Assuming this is the case, we could either make them in Rocklin or EOL. If the monthly volume was too low, and building them in Rocklin displaces new products (that'd be the case right now) then it would've gone into EOL.
And as you know, we are also designing chips. You could say our first chip was the SX in 1997, designed by Ubicom with our close participation. Six years later you saw the Propeller 1, and seven years later you will see the Propeller 2. These efforts are hugely expensive, and we've achieved them by reinvesting every single dollar you spend at Parallax with only occasional reliance on credit. We support an R&D team of 3+, a half-dozen external consultants, terrifying software license expenses, unknown-outcome shuttle runs that could buy a condominium, and responsibility to bring a device to market (characterization, testing, software tools, hardware boards, trainings, etc.). The typical business model for making chips involves external funding for small companies, and reliance on big revenue for existing large companies. We're a small, small player. You wouldn't want us to do that because we'd be pandering to the lenders and it would force an identity change.
Having long-term goals like we do often puts us in the position of making difficult trade-offs like you're seeing. It's a very simple business model to buy and sell parts, to make adapter boards but to deliver what we think is really creative (chips!) is a far more challenging and rewarding business model. If somebody's frustrated about this, it should be Phil since he developed the ServoPal. I don't think we gave him any advance notice.
Nobody is going to force-feed Propellers to you. We're going to make all BS2s forever. But hang in there with the Propeller wave just in case - there's a good chance it'll be looking better than a BS2 to you.
How about open sourcing the board, including layout and schematic. Then maybe someone here -- who has a lower general overhead -- could produce them. I'm guessing the "Pal" part makes it a PhiPi board? I imagine Phil got a cut, but if there is indeed a royalty involved, could you work something out?
-- Gordon
Only Duane noticed and cared (sniff, sniff) when I fired up my Prop-BoE 6 months ago... operating a RELAY, natch!
I support that entirely, and maybe somebody else wants to make them. In fact, we'd even buy them and sell them if they can be supplied by somebody else. But don't expect us to buy more than a month's worth of inventory. This would be up to PhiPi to work out with a forum member, or maybe he wants to do it all by himself.
Hmmm. I could make that chip right now in small quantities... and sell for $15 while making a tidy profit.
-Phil
If we could just have a few minutes with him alone he'd see the light. With Andy's new objects it's easier on a Propeller than anything I've ever seen http://learn.parallax.com/node/290. These 9th graders ran circles around me http://forums.parallax.com/entry.php?833-Parallax-President-Ken-Gracey-gets-Hands-on-Teaching-Robotics and now they're building an GPS-guided craft that will cross Lake Tahoe.
The Propeller has become EASIER to use over time, and maybe erco hasn't taken a look at some of the newer examples. erco, if you come up here for a day I'll pick you up at the airport. We can ride bikes the first half of the day and program Propellers the second half, and you can be home in time to tuck the girls into bed.
I admit I didn't see this. Shame on me! That's awesome, erco! I will spend more time on the forums.
Jim
The new PropBoe objects have definitely made things easier. I particularly like the servo drive object which once calibrated makes for pretty reliable open loop control. My one criticism of them is that in some ways they bury too much of the details within the subordinate objects (I have the same criticism of the Arduino libraries). Not seeing the pin manipulations in line tends to make certain operations black boxes. I know it is more modular, but from a learning point of view it might not be for the best.
Erco, I've also used the BS2 functions from the OBEX to port BS2 code to Spin fairly rapidly. Over in the Robot forum I ported Phil's Red Eye line follower to Spin using them. I recently enhanced them a bit to include cursor control by borrowing functions from the PropBoe's enhanced serial terminal object. Once you're over the Spin syntax hump you can port code fairly quickly.
May I recommend the Propeller Servo Controller USB to you as a superior replacement to the ServoPal?
http://www.parallax.com/Store/Microcontrollers/PropellerDevelopmentBoards/tabid/514/CategoryID/73/List/0/catpageindex/2/Level/a/ProductID/595/Default.aspx?SortField=ProductName%2cProductName
- You could control it with a single pin from the BS/2, or two pins if you wanted to read back from it.
- it can control 16 servos, or you can use some of the I/O's for inputs
- it has a USB port, and you could use it to get your feet wet with the Prop
Sure, it costs more in absolute terms... but not on a per-port basis:
- Servo Pal: $14.99 for two ports, so it is ~$7.50 per servo port
- PropServo: $39.99 for sixteen ports, so it is ~$2.50 per servo port
So if your robots need a lot of servos, or can use more inputs, the Prop Servo Controller is a MUCH better deal!
Hope this helps,
Bill
p.s.
For a Propeller based dedicated robot controller see
http://www.mikronauts.com/roboprop/
I share these thoughts, Martin. We can speed students towards quick results with these new objects, but it's almost too easy. They look at servo speeds in terms of "fast, one direction" as -100, and "fast the other direction" as +100. This ease of use is almost necessary for all of the new introductory electronics and robotics courses, and the real learning isn't happening until later in the curriculum. Not fair for us, having learned from the bottom up, and maybe not the best approach for real education. I think the quick-learning-by-doing method is unfortunately reinforced by the competition any subject faces in the classroom: smart phones, sports, video games and other gotta-see-it-work-now-or-else instant satisfaction demands.
I am definitely experimenting with various ways of teaching in my middle school robotics course. Sometimes I give it to them at a high level, other times they have to learn the real way.
Erco, that might not be that hard to build. Although instead of a PIC I would use an ATMega328P in a form factor like a DorkBoard from Wulfden http://www.wulfden.org/TheShoppe/freeduino/dorkboard.shtml.
What I would do is have a daughter board drop right onto of the BOE's four servo and power headers. That board would have four servo headers with its own 5v or Vin selector header. The four BS2 I/O's would connect to four inputs on the ATMega328P with four pins on the ATMega328P connecting to the four servo pins. A piezo speaker on the daughter board could replicate the soundPal's functions with headers to access the ADC as well.
Parts of the firmware wouldn't be that hard to put together. Basically the ATMega328P would listen to pulsin on one if its input pins and pulsout on its output pins. Another pin could emulate the soundPal's ability to play sound which strikes me as the hardest part of the project. The remaining two pins could be use serial I/O to talk to the ADC which falls somewhere in between in complexity.
And to all, I'm neither afraid nor ignorant of the Prop, I am using it and working thru the manuals. Yet the Stamp is still useful and educational. I really like its minimalist qualities. I teach programming to noobs in house. Let's face it, BASIC is infinitely easier than SPIN for beginners. And per Martin_H, it's still quicker to bang out a small program from scratch on a BS2.
So sure, you have my Stamps. When you pry them out of my cold dead hands!
Could the ServoPal be sold as a kit? Drop the PICs in a programmer, and each kit has a PCB, PIC, and the required passives, up to the end-user to solder. You can have other companies manufacture the boards for ultra cheap, and kitting them shouldn't be difficult.
That's certainly a viable option and preferable to no ServoPal. Experienced people love building kits. But moreso, I think the ServoPal is a great stepping stone for noobs who may not be comfy soldering.
-Phil
Also, stay tuned for more information about the new website, we're getting very close!
I see the ServoPal is still available at http://www.parallaxdirect.com/cart/catalog/Parallax-28824-ServoPAL-205.html and http://www.robotshop.com/parallax-servopal-dual-servo-controller.html and http://in.mouser.com/ProductDetail/Parallax/28824/?qs=sGAEpiMZZMt7FrWooXVB19GIoNQdOdNo and maybe more. Is that simply "get 'em while they last" ?