Problem with BOE-BOT servomotors

thomas_pittin

Dear all,

I have a problem with the servomotors of my Boe Bot.

I explain my issue;

I tryied to test my servomotors with this command:

PULSOUT 13, 650
PULSOUT 12, 850
PAUSE 20

when I test one servomotor with this command "PULSOUT 13, 650 or 850" it works! but when I try both servomotors together, one of them turns only in one way even if I change the pulses (650 clockwise, 850 counterclockwise)

I hope you can help me

GordonMcComb

Be sure to calibrate both motors first. The instructions and sample code are in the BOE Bot guide.

Also be sure you're running your BOE Bot with a fresh set of batteries in the 6V battery pack. Old/weak batteries, or trying to use a 9V "transistor" battery, won't deliver enough current to run two servos at once.

erco

Jeepers, double post: http://forums.parallax.com/showthread.php/153037-Problem-with-BOE-BOT-servomotors

At least Gordon and I are trackin'.

thomas_pittin

erco wrote: »

Jeepers, double post: http://forums.parallax.com/showthread.php/153037-Problem-with-BOE-BOT-servomotors

At least Gordon and I are trackin'.

Sorry for double post

how many current needs the boe-bot in order to work properly?

carline

Thomas,

Try swapping the servos and associated output pins to see if the problem follows the pins or
stays with the servo.

thomas_pittin

carline wrote: »

Thomas,

Try swapping the servos and associated output pins to see if the problem follows the pins or
stays with the servo.

---

I tried to change the pins (before Left = pin13, after Left = pin12) but nothing changed.

erco

Once again, have you "nulled" your servos so they are both centered/stopped at pulsout 750? Have you changed to brand new batteries?

GordonMcComb

thomas_pittin wrote: »

how many current needs the boe-bot in order to work properly?

42.

Okay, old Hitchhiker's Guide joke. Don't worry about the current numbers. Just use fresh AAs batteries, and not old ones, and certainly not a 9V battery.

Like Erco sez, be sure to calibrate those motors. They don't always come from the box calibrated.

thomas_pittin

GordonMcComb wrote: »

42.

Okay, old Hitchhiker's Guide joke. Don't worry about the current numbers. Just use fresh AAs batteries, and not old ones, and certainly not a 9V battery.

Like Erco sez, be sure to calibrate those motors. They don't always come from the box calibrated.

Now i use a fresh AAs rechargeable batteries and i tried to calibrate both motors with this code:

Left motor

DEBUG "Program Running"


DO
PULSOUT 13, 750
PAUSE 20
LOOP

Right motor

DEBUG "Program Running"


DO
PULSOUT 12, 750
PAUSE 20
LOOP

now they seems to work!!!

erco

thomas_pittin wrote: »

Now i use a fresh AAs rechargeable batteries

Therein lies the rub. NiMH cells are lower voltage than alkalines. Are you using 4 or 5 cells?

See http://www.parallax.com/search?search_api_views_fulltext=boe+boost

RDL2004

or this

5 AA cell battery holder

http://www.parallax.com/product/753-00007

erco

Good call, Rick!