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BOT BOARD II + BASIC STAMP 2IC

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Rookie ( offline )
Posts: 12
Posted: 2009-03-25 17:06 
Im still stuck at this I/O pin to get power from the VS or VL.

I don't understand what it means by peripheral, the MCU or the servo...

I connected the jumper just like in the pretty picture from the user guide (to the VS).

I just finished connecting 3 servos, connected the AC adapter...it's all ready, as soon as I get the "OK" that it's all good (im worried about that jumper not to burn the servos/MCU or smt) im gonna try to start programming it.


Rookie ( offline )
Posts: 12
Posted: 2009-03-25 17:09 
So I switch the pin to VS instead of VL (i think you made a mistake and you were refering to VL not VS).

and use the power I get from VS not VL.

Am I okay till now ?

VL is powered by 9VDc battery.

VS is powered by 6.9VDC adapter.

Jumper for VS+VL is disconnected.

now Ill move the pin for I/O from VL to VS.

so I should be okay, right?



1 more thing.

in the pretty picture from the UG with the description "Applies VS and VL to
analog inputs 0 and 1."

am I to leave only the VS and take out the VL jumper?

I`m guessing yes since it will be 5+6.9 = ~12VDC for the servo...


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Guru ( offline )
Posts: 9258
Posted: 2009-03-25 17:32 
um, ok...

VS is Voltage for Servos.

VL is Voltage for Logic.

Logic is defined as 5vdc for the electronics on the board, installed microcontroller, sensors, etc. Peripherals is defined as sensors or other electronics that can connect to 5vdc.

You are correct to remove the jumper to separate logic from servo supplies, but you are wrong in your thinking of what it would do if it was connected. The jumper in place would short 6.9vdc to 9vdc. The 9vdc battery would lose the battle.

I hope EddieB isn't replying too. :cry:

_________________
Jim Frye, the Robot Guy
http://www.lynxmotion.com
I've always tried to do my best...


Rookie ( offline )
Posts: 12
Posted: 2009-03-25 17:42 
okay so Now Im ready to go. (plugged it all in, the MCU still works so no damage till now)

tried to compile your program but as you said it needs a bit of polishing.

if it's not to much to ask maybe you could write the whole thing with the allocated variables, since I`m new to BS programming, and I don`t seem to make any progress with the BS ref. manual.

I connected 3 servos, but just 2 moving is enough for me. they are connected to :


P0, P4, P8

so the

OOOO
OOOO
OOOO

look like

P0 P4 ..and so on
XOOO XOOO XOOO
XOOO XOOO XOOO
XOOO XOOO XOOO

if you could help it would be swell ... dont want some1 else to do the work for me but 5 days ain`t enough to learn a programming language, build a robot etc. :) and I need an example of a code that has external consequences like moving a motor.

(BTW, i did the hellow world program xD )

thanks for all the replies!


User avatar
Guru ( offline )
Posts: 9258
Posted: 2009-03-25 17:51 
You don't need to read the entire programming guide to grasp setting up a variable. The numbers you need to store are from 250 to 1250. So can you tell me what size variable is required.

I'm sorry to hear you only have 1 week to complete your project. I will tell you what you need to figure out. I've already given you ample info to get started.

Crack the manual and read the section for setting up the variables. You will have a better feeling if you figure it out.

_________________
Jim Frye, the Robot Guy
http://www.lynxmotion.com
I've always tried to do my best...


Rookie ( offline )
Posts: 12
Posted: 2009-03-25 17:53 
name VAR word .

that's what I`ll be using:). ill keep reading try to fix the code you gived me and if I get stuck I`ll ask, but 1st I want to give it a go.

BTW i just read the servos section on lynxmotion and it says that my servo model needs a max voltage of 6Vdc.

I put 6.9Vdc in it...won't it get burned? plz tell me "no"...

cuz I didn`t read anything about a voltage regulator beeing used for the servos and I picked the VS source not the VL wich is regulated.


Last edited by Buzdugan on 2009-03-25 18:00, edited 1 time in total.

User avatar
Guru ( offline )
Posts: 9258
Posted: 2009-03-25 17:59 
Servos will work at 4.8 to 7.2vdc. I know this from experience. Some servos will get a little jittery at higher voltages. Servos have more power with more voltage. Technically the lifetime of the servo is shortened a bit at higher voltages. But to answer your question the smoke does not come out rapidly until around 11vdc. Your 6.9vdc is just fine. Don't freak out about it.

_________________
Jim Frye, the Robot Guy
http://www.lynxmotion.com
I've always tried to do my best...


Guru ( offline )
Posts: 2158
Posted: 2009-03-25 18:01 
"burned"... probably not immediatly... your power supply will probably die before they do... but it's not real healthy for the servos either.

do you have a r/c hobby shop locally where you can just grab an RX pack (usually 4 nicd/nimh in series) and a cheapo charger?

you could also use (3) alkaline "D" cells in series... note that (4) might be too much volts when freshly/first installed. for what you are doing the "D" cells would probably last nearly the 5 days... duracells are like 18,000mahr... energizer more like 15,000mahr.

just throwing out suggestions. :?


Guru ( offline )
Posts: 2158
Posted: 2009-03-25 18:02 
lol... robodude and I have different thresholds of pain for what's healthy on servos. :lol:


Rookie ( offline )
Posts: 12
Posted: 2009-03-25 18:06 
Thanks!

I'm a little worried...since I don`t have much info or knowledge about this...

I got the servos moving xD

temp1 VAR Word
temp2 VAR Word
x VAR Byte

this is how I allocated the vars and they ....move

now I`ll just start experimenting till tomorrow morning and afterwards I might get busy with the hardware part.

I`ll let you know how it turns out, and if I succeed will post some pictures.

Thank you all for your help!!!!


User avatar
Guru ( offline )
Posts: 9258
Posted: 2009-03-26 10:39 
Glad you got it going! 8)

_________________
Jim Frye, the Robot Guy
http://www.lynxmotion.com
I've always tried to do my best...


User avatar
Guru ( offline )
Posts: 9258
Posted: 2009-03-26 12:09 
EddieB wrote:
lol... robodude and I have different thresholds of pain for what's healthy on servos. :lol:


Well it's not as bad as it might look. There are a couple ways of looking at the term "voltage" in this context. When referencing batteries a 6.0vdc battery will actually be 7.1vdc right off the charger. Of course this will drop as it's being used. But it's going to be higher than the rated 6.0vdc for a good while. A regulated wall pack voltage should be much closer to the rated value, and not vary much.

Normally I stick to the 6.0vdc limit rigidly, but there are situations where higher voltages are not a major problem. Because this is not a project with a bunch of digital servos supporting a great deal of weight. (The tripod robot videos on youtube use low end analog servos and don't appear to be supporting a great deal of weight.) The little amount of power consumed by the servo will allow the use of 6.9vdc. In fact we used to include 7.2vdc batteries in the old H2 12 servo walker kits. The 422 servos handled the higher voltage just fine. I miss that kit. :cry:

_________________
Jim Frye, the Robot Guy
http://www.lynxmotion.com
I've always tried to do my best...


Rookie ( offline )
Posts: 12
Posted: 2009-03-27 08:09 
1st when I read about D-cell battery and looked it on google (in our country it has a different name...smt like R12) thought it was 2 much, but now I see why you recommend it. It' has the same voltage as regular AA
Batteries and rechargables (1.5 / 1.2V), only that they last longer...from 2400mah to 12000mah, so my robot (soon 2 be) won't get dry so fast.

Thanks guys! didn`t know about this... I`m gonna go check tomorrow for some D cell rechargables and a charger ...hope they are cheap.


found some GP Dcells for 5000mah...that's what it says on webpage...

will look more into it.


Guru ( offline )
Posts: 2158
Posted: 2009-03-27 10:06 
Hold on a second :!:

I did not realize you were not US based so forgive my using the dumbed down name for cell size. What I am referring to are alkaline primary cells such as this (being 34mm dia x 61.5mm long) which are not rechargable. This type of battery is an off the shelf commodity item (in the US at least) used for toys and radios. So the idea behind my suggestion was along the lines that you could run down to the local Radio Shack (actually in most cities here in the US) to buy a 3-cell holder and some relatively cheap disposable batteries that should get you through to your deadline.

:arrow: A rechargable battery, either NiCd or NiMH, will need at least 4 cells since they have a lower operating voltage (1.2V) than non-rechargable Alkaline or Carbon-Zinc chemistry cells (1.5V). Both chemistries tend to be somewhat higher than their rated voltage when fresh out of the charger or the plastic package.

Actually if RobotDude is comforatable with running the servos above 6V then you could probably get away with 4 Alkaline primary cells too.


Guru ( offline )
Posts: 2158
Posted: 2009-03-27 10:19 
oh yeah, I believe the IEC designation for what US calls a "D" cell is "LR20".


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