Scratch

chalkmarrow · 2008-06-12 17:36:00

I'm happy to see there's a forum just for sensor boards, and welcome to the forums, Lutz. We just received our board, and it works great.

FYI for anyone playing with the resistance values, we did some experiments and figured out that, for our board, the resistance sensor value (0-100) that the PicoBoard produces is related to the actual resistance (in KOhms) across the alligator clips by the something like the following equation:

sensor value = a*ln(bx+1) where, approximately:

a=19.5
b=0.9

BUT, if you are only interested in low resistance values between 0-10 KOhm, the following simple relation works real well:

sensor value = a*x, where a is approximately 5.57

Last edited by chalkmarrow (2008-06-16 12:38:46)

Paddle2See · 2008-06-12 20:50:53

I've been thinking about getting a Scratchboard...have you done anything interesting with it yet? Keep us posted!

Cyclone103 · 2008-06-12 21:24:43

chalkmarrow wrote:
I'm happy to see there's a forum just for Scratchboards, and welcome to the forums, Lutz. We just received our scratchboard, and it works great.

FYI for anyone playing with the resistance values, we did some experiments and figured out that the resistance sensor value (0-100) that the scratchboard outputs is related to the actual resistance (in Ohms) across the alligator clips by the something like the following equation:

Value = a + b*ln(Resistance)

where, approximately:

a=-8.264
b=1.450

This relation is more accurate for low resistance values than it is for high resistance values.

Who is "we"? Are you really a team of people that I thought was one person right until now??

chalkmarrow · 2008-06-12 22:46:50

Paddle2See: Just playing with it now. It's pretty fun, really. I wish it could produce some form of output (rather than being exclusively input), but perhaps in some later rev. There's a project in progress that I'll post a prototype simulation for later this week.

Cyclone103: I'm old like Paddle2See (xD) , but this login is used by my kids as well, from time to time. We do projects together so I can teach them how to program.

Last edited by chalkmarrow (2008-06-12 22:48:43)

Bluestribute · 2008-06-12 22:54:46

chalkmarrow wrote:
Paddle2See: Just playing with it now. It's pretty fun, really. I wish it could produce some form of output (rather than being exclusively input), but perhaps in some later rev. There's a project in progress that I'll post a prototype simulation for later this week.

Cyclone103: I'm old like Paddle2See (xD) , but this login is used by my kids as well, from time to time. We do projects together so I can teach them how to program.

I also thought that you were like a high schooler or something. And would you recommend getting a Scratch or Pico board?

chalkmarrow · 2008-06-12 23:57:39

Bluestribute: It looks to me like they are exactly the same, but the Scratch board is 10-20 dollars cheaper for some unknown reason.

Bluestribute · 2008-06-12 23:58:21

I might see if I can get one ("MOM!")

Bluestribute · 2008-06-13 00:01:14

Are thet easy to hook up?

geckofreak · 2008-06-13 10:35:22

Bluestribute wrote:
Are thet easy to hook up?

They just fit in a usb slot. Of coarse their easy to hook up.

Bluestribute · 2008-06-13 13:36:25

geckofreak wrote:
Bluestribute wrote:
Are thet easy to hook up?
They just fit in a usb slot. Of coarse their easy to hook up.

But it says I need to download all of this hardware and stuff

Cyclone103 · 2008-06-13 16:47:55

chalkmarrow wrote:
Paddle2See: Just playing with it now. It's pretty fun, really. I wish it could produce some form of output (rather than being exclusively input), but perhaps in some later rev. There's a project in progress that I'll post a prototype simulation for later this week.

Cyclone103: I'm old like Paddle2See (xD) , but this login is used by my kids as well, from time to time. We do projects together so I can teach them how to program.

Thats nice! If I was old enough to have kids, I am sure I would be teaching them too. Most of your project scripting confuses me utterly smile but I try to figure out how it works.

Lutz · 2008-06-16 10:53:58

Bluestribute wrote:
geckofreak wrote:
Bluestribute wrote:
Are thet easy to hook up?
They just fit in a usb slot. Of coarse their easy to hook up.
But it says I need to download all of this hardware and stuff

They are quite easy to use. There is a driver for the Cable that hooks up the board to the computer, but that's it.

chalkmarrow · 2008-06-16 12:23:17

I agree with Lutz: They made it really easy to set up. An 8-year old installed it and downloaded the drivers by himself on my PC (he was eager to use it, and I wasn't home at the time).

Bluestribute · 2008-06-16 12:23:55

chalkmarrow wrote:
I agree with Lutz: They made it really easy to set up. An 8-year old installed it and downloaded the drivers by himself on my PC (he was eager to use it, and I wasn't home at the time).

Alright. I'll ask my mom (or other relatives *wink wink*)

terminator68 · 2008-06-16 14:02:08

Wat's a scratch board, Paddle?

terminator68 · 2008-06-16 14:04:36

how much is a scratch board if ya have to buy it, chalkmarrow?

chalkmarrow · 2008-06-16 15:42:21

terminator68: i think it's about $50:

http://www.picocricket.com/order-picoboard.php

Scratch

archived forums

#1 2008-06-12 17:36:00

Resistance Values

#2 2008-06-12 20:50:53

Re: Resistance Values

#3 2008-06-12 21:24:43

Re: Resistance Values

chalkmarrow wrote:

#4 2008-06-12 22:46:50

Re: Resistance Values

#5 2008-06-12 22:54:46

Re: Resistance Values

chalkmarrow wrote:

#6 2008-06-12 23:57:39

Re: Resistance Values

#7 2008-06-12 23:58:21

Re: Resistance Values

#8 2008-06-13 00:01:14

Re: Resistance Values

#9 2008-06-13 10:35:22

Re: Resistance Values

Bluestribute wrote:

#10 2008-06-13 13:36:25

Re: Resistance Values

geckofreak wrote:

Bluestribute wrote:

#11 2008-06-13 16:47:55

Re: Resistance Values

chalkmarrow wrote:

#12 2008-06-16 10:53:58

Re: Resistance Values

Bluestribute wrote:

geckofreak wrote:

Bluestribute wrote:

#13 2008-06-16 12:23:17

Re: Resistance Values

#14 2008-06-16 12:23:55

Re: Resistance Values

chalkmarrow wrote:

#15 2008-06-16 14:02:08

Re: Resistance Values

#16 2008-06-16 14:04:36

Re: Resistance Values

#17 2008-06-16 15:42:21

Re: Resistance Values

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