Revisions to Board of Education - your Input Needed
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Posts: 46,084
Hello Stampers,
Based on your requests we will be making revisions to the Board of
Education. The primary purpose of the revision is to add a 3-position
power switch - the most common request particularly for educational
customers. This is how the switch would work:
Position 0 - no power
Position 1 - power to Stamp, none to servos
Position 2 - power to everything
There seems to be no place to put the reset button. Can you handle using
a slide switch for reset?
Any other wishes for this product? Of course, such requests need to be
weighed against need, cost, etc. so some people don't get stuck paying
for features that only a few need.
How about a jumper to select Vdd or Vin for servos?
As you can see, we're a bit cautious with this due to the high number in
use and it's popularity in education. Your feedback is appreciated.
Sincerely,
Ken Gracey, Parallax
Main Web Site: http://www.parallaxinc.com
Educational: http://www.stampsinclass.com
Download 75 BASIC Stamp Applications at www.parallaxinc.com/nutsandvolts
Based on your requests we will be making revisions to the Board of
Education. The primary purpose of the revision is to add a 3-position
power switch - the most common request particularly for educational
customers. This is how the switch would work:
Position 0 - no power
Position 1 - power to Stamp, none to servos
Position 2 - power to everything
There seems to be no place to put the reset button. Can you handle using
a slide switch for reset?
Any other wishes for this product? Of course, such requests need to be
weighed against need, cost, etc. so some people don't get stuck paying
for features that only a few need.
How about a jumper to select Vdd or Vin for servos?
As you can see, we're a bit cautious with this due to the high number in
use and it's popularity in education. Your feedback is appreciated.
Sincerely,
Ken Gracey, Parallax
Main Web Site: http://www.parallaxinc.com
Educational: http://www.stampsinclass.com
Download 75 BASIC Stamp Applications at www.parallaxinc.com/nutsandvolts
Comments
mine just a few short years ago, and it is amazing how archaic it now
seems! The switch will be a big imrovement! I had made a stand that
elevated the BOEbot's wheels off the ground so it doesn't run away as
I download programs. I like the "IR headers" that are on the Toddler
board. Any way that you could incorporate them onto the BOE?
Steve
--- In basicstamps@y..., "Ken Gracey" <kgracey@p...> wrote:
> Hello Stampers,
>
> Based on your requests we will be making revisions to the Board of
> Education. The primary purpose of the revision is to add a 3-
position
> power switch - the most common request particularly for educational
> customers. This is how the switch would work:
>
> Position 0 - no power
> Position 1 - power to Stamp, none to servos
> Position 2 - power to everything
>
> There seems to be no place to put the reset button. Can you handle
using
> a slide switch for reset?
>
> Any other wishes for this product? Of course, such requests need to
be
> weighed against need, cost, etc. so some people don't get stuck
paying
> for features that only a few need.
>
> How about a jumper to select Vdd or Vin for servos?
>
> As you can see, we're a bit cautious with this due to the high
number in
> use and it's popularity in education. Your feedback is appreciated.
>
> Sincerely,
>
> Ken Gracey, Parallax
> Main Web Site: http://www.parallaxinc.com
> Educational: http://www.stampsinclass.com
>
> Download 75 BASIC Stamp Applications at
www.parallaxinc.com/nutsandvolts
>
>Based on your requests we will be making revisions to the Board of
>Education. The primary purpose of the revision is to add a 3-position
>power switch - the most common request particularly for educational
>customers. This is how the switch would work:
>
>Position 0 - no power
>Position 1 - power to Stamp, none to servos
>Position 2 - power to everything
I have the feeling that slide switches are unreliable, unless you get
the ones that are hideously expensive. I would prefer a plugin
jumper that can disconnect the servo, or select Vdd or Vin (per
below).
>There seems to be no place to put the reset button. Can you handle using
>a slide switch for reset?
rather not!
>Any other wishes for this product? Of course, such requests need to be
>weighed against need, cost, etc. so some people don't get stuck paying
>for features that only a few need.
Maybe this has already been done, but I would like to see a ground
layout in a "star" pattern centered on the V- pin of the regulator.
One fat arm directly to the Vss pin on the Stamp, another arm
directly to the Vss pin for the breadboard, and another to the
expansion connector and another to the servo ground. On the BOEs I
have (older models), the ground runs around the edge of the board
through the mounting holes, and the breadboard Vss is at the end of
the chain.
>
>How about a jumper to select Vdd or Vin for servos?
Yes, plus OFF.
>
>As you can see, we're a bit cautious with this due to the high number in
>use and it's popularity in education. Your feedback is appreciated.
>
>Sincerely,
>
>Ken Gracey, Parallax
>Main Web Site: http://www.parallaxinc.com
>Educational: http://www.stampsinclass.com
As for the reset switch, I prefer a pushbutton that can be operated
with one finger, instead of a slide switch which requires several
fingers to manipulate.
I would also like to suggest two minor additions to the labels on the
sockets above the breadboard, to include a second power convention.
Original: Vdd
New: Vdd(+5v)
Original: Vss
New: Vss(gnd)
Thanks
Dave
the Sumo board sized switches that would handle the current two stalled
servos would draw -- has this been a problem with the switch Parallax uses?
> >Based on your requests we will be making revisions to the Board of
> >Education. The primary purpose of the revision is to add a 3-position
> >power switch - the most common request particularly for educational
> >customers. This is how the switch would work:
> >
> >Position 0 - no power
> >Position 1 - power to Stamp, none to servos
> >Position 2 - power to everything
>
> I have the feeling that slide switches are unreliable, unless you get
> the ones that are hideously expensive. I would prefer a plugin
> jumper that can disconnect the servo, or select Vdd or Vin (per
> below).
Stamp chip regulator to the 1 Amp Low Drop regulator on the board.
It could eliminate the need for extra regulators on each of the
AppMod boards.
I recommend against trying to power the servos from the same
regulator as the processor. Unless all the electronics are powered
from the Stamp chip, there will be a lot of noise added to the
electronic power from the servo motors.
Speaking of noise, I'd recommend adding some 0.1uF ceramic caps to
the +5 regulated line to keep down the high frequency noise.
Love the power switch, not real partial to slide switches.
An advantage of the 3 position switch, is you can power the board
with a DC adapter and just not use the servos while developing code.
A disadvantage is if you overshoot the "Position 1 - power to Stamp,
none to servos" position, you can damage the servos. I'll bet that
will happen a lot in a classroom. I'm not sure how to easily
interlock it out but a 3 position switch seems like it is asking for
it.
How about
Position 0 - power to Stamp, none to servos
Position 1 - no power
Position 2 - power to everything
That MIGHT be safer but still no guarantees.
Harry
Stamp Robotics to the next level
www.bluebelldesign.com
--- In basicstamps@y..., "Ken Gracey" <kgracey@p...> wrote:
> Hello Stampers,
>
> Based on your requests we will be making revisions to the Board of
> Education. The primary purpose of the revision is to add a 3-
position
> power switch - the most common request particularly for educational
> customers. This is how the switch would work:
>
> Position 0 - no power
> Position 1 - power to Stamp, none to servos
> Position 2 - power to everything
>
> There seems to be no place to put the reset button. Can you handle
using
> a slide switch for reset?
>
> Any other wishes for this product? Of course, such requests need
to be
> weighed against need, cost, etc. so some people don't get stuck
paying
> for features that only a few need.
>
> How about a jumper to select Vdd or Vin for servos?
>
> As you can see, we're a bit cautious with this due to the high
number in
> use and it's popularity in education. Your feedback is appreciated.
>
> Sincerely,
>
> Ken Gracey, Parallax
> Main Web Site: http://www.parallaxinc.com
> Educational: http://www.stampsinclass.com
>
> Download 75 BASIC Stamp Applications at
www.parallaxinc.com/nutsandvolts
and GND traces supplying current as fat as possible. Further
filtering by adding a pi filter to the servo supply can also help.
Adding 10 uF 16 V, low ESR ceramic caps to each servo connector will
help squash those low frequency voltage burps in the 5V supply. A
simple 2 pin header with a shunt will do the trick for removing power
from the servos. A push button for the reset switch is a must. I
realize that adding parts is not always an option when you want to
meet a certain unit cost but adding bulk capactance can go a long way
in preventing those noise induced intermittent failures.
Jason
--- In basicstamps@y..., "harrywlewis" <harry_w_lewis@h...> wrote:
> I recommend moving the +5 on the AppMod connector from the BASIC
> Stamp chip regulator to the 1 Amp Low Drop regulator on the board.
> It could eliminate the need for extra regulators on each of the
> AppMod boards.
>
> I recommend against trying to power the servos from the same
> regulator as the processor. Unless all the electronics are powered
> from the Stamp chip, there will be a lot of noise added to the
> electronic power from the servo motors.
>
> Speaking of noise, I'd recommend adding some 0.1uF ceramic caps to
> the +5 regulated line to keep down the high frequency noise.
>
> Love the power switch, not real partial to slide switches.
> An advantage of the 3 position switch, is you can power the board
> with a DC adapter and just not use the servos while developing
code.
> A disadvantage is if you overshoot the "Position 1 - power to
Stamp,
> none to servos" position, you can damage the servos. I'll bet that
> will happen a lot in a classroom. I'm not sure how to easily
> interlock it out but a 3 position switch seems like it is asking
for
> it.
>
> How about
> Position 0 - power to Stamp, none to servos
> Position 1 - no power
> Position 2 - power to everything
> That MIGHT be safer but still no guarantees.
>
> Harry
> Stamp Robotics to the next level
> www.bluebelldesign.com
>
> --- In basicstamps@y..., "Ken Gracey" <kgracey@p...> wrote:
> > Hello Stampers,
> >
> > Based on your requests we will be making revisions to the Board of
> > Education. The primary purpose of the revision is to add a 3-
> position
> > power switch - the most common request particularly for
educational
> > customers. This is how the switch would work:
> >
> > Position 0 - no power
> > Position 1 - power to Stamp, none to servos
> > Position 2 - power to everything
> >
> > There seems to be no place to put the reset button. Can you
handle
> using
> > a slide switch for reset?
> >
> > Any other wishes for this product? Of course, such requests need
> to be
> > weighed against need, cost, etc. so some people don't get stuck
> paying
> > for features that only a few need.
> >
> > How about a jumper to select Vdd or Vin for servos?
> >
> > As you can see, we're a bit cautious with this due to the high
> number in
> > use and it's popularity in education. Your feedback is
appreciated.
> >
> > Sincerely,
> >
> > Ken Gracey, Parallax
> > Main Web Site: http://www.parallaxinc.com
> > Educational: http://www.stampsinclass.com
> >
> > Download 75 BASIC Stamp Applications at
> www.parallaxinc.com/nutsandvolts
as I frequently change the BS. Maybe providing a Textool socket right
away would make the BOE to expensive. However it may be handy to have
some space around the socket so it will still be possible for the
user to add a ZIF socket himself.
I wanted to do the same with my INX1000 board but there was not
enough space.
regards