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Imaginova
02-05-2007, 07:53 PM
Hi,
I want to know what does a typical Accelerometer cost. Will it be available at LAJPAT RAI MARKET, Delhi..
Thanks..

vikas
02-05-2007, 10:40 PM
No accelorometers are not availible india

Cost depends on what u want

http://www.sparkfun.com/commerce/categories.php?cPath=23_80

Imaginova
02-06-2007, 10:01 AM
hey i m working on self balancing bot. I wanna use it for distance sensing.
How do i get the specifications??
THanks

happy_99
02-06-2007, 02:47 PM
hi

For distance measurement why do u need accelerometers?

regds

happy_99

Imaginova
02-06-2007, 07:09 PM
plz suggest any technique for it???

docel
02-06-2007, 08:56 PM
...probably for "balancing"........
Although, it can be achieved with a couple of LDRs/LEDs and an ADC....

happy_99
02-11-2007, 01:59 PM
oh yea for balancing..thats correct.

pls check for ADXL202

regds

happy_99

vikas
02-11-2007, 04:19 PM
http://www.geology.smu.edu/~dpa-www/robo/nbot/

technique + resources on this page ... lots of it.

ppppking04
02-11-2007, 05:23 PM
...probably for "balancing"........
Although, it can be achieved with a couple of LDRs/LEDs and an ADC....

Won't it be dependent on the surface for that? irregular reflectivity and such?

docel
02-12-2007, 01:21 AM
...probably for "balancing"........
Although, it can be achieved with a couple of LDRs/LEDs and an ADC....

Won't it be dependent on the surface for that? irregular reflectivity and such?

:?: :?: :?:

ppppking04
02-12-2007, 06:52 AM
Balancing using distance measurement (with ldr/adc).

The readings will vary depending on the surface the robot is over. And as far as i can see for neat balancing you would want consistent readings.

docel
02-12-2007, 10:43 PM
No pratap...! Not for dist. measurement and balance correction.
I was suggesting something else....a homebrew Tilt sensor!

ppppking04
02-13-2007, 06:20 AM
I knew you would come up with something great! :)

So how to go about brewing a tilt sensor? Whats the idea

vikas
02-13-2007, 02:07 PM
im interested too :)

shashak
02-13-2007, 05:55 PM
i have an idea !!!!!!

not know, it is feasible or not. How about with mercury like in mercury switch (never saw that also :)) now we have tube in which inner walls have variable resistance point and one point (metal contact) it at base , so when tube is tilted the mercury make contact with variable resistors point and the resistance at base point is change so we can calculate the tilt :)

docel
02-15-2007, 03:58 AM
OK!
Here's a hint!!
Inverted heavy triangle, 2 pairs of LED-LDRs,

vikas
02-15-2007, 09:09 PM
Docel i tried this ... the whole heavy triangle which is supposed to remain stationary gives results when the robot moves side ways slowly :) ... but if you leave the robot and let it fall , the triangle does not give that a fast a response time. I never thought of this problem before starting :).

Another way i found was to use a combination of IR tx/rx and use the intensity of light reflected off ground to determine the tilt ... way cheap but the only issue is that you require a constant surface !

docel
02-18-2007, 12:15 AM
Fast response is possible using LED source & Led detector ( IR or Visible).
The Heavy triangle needs to be 'damped' to prevent oscillations.
This cannot be applied to slow gear-box.
Works like a dream with Servos!!!
speed can be "graded " using multiple sensors with ADC thresholds.

vikas
02-18-2007, 12:36 AM
The LED response / daming is not the problem.

The problem is that when the robot slips to one side the whole of the triagle also goes along with it :) ... i should have made a video. Its ok if its slow (then it works fine) but not when it fast when its actually falling. But i dont think such a thing is possible in a small robot ( i tried many variateon in my bot and didnt work out ... next im gonna give IR based one a try :) ).

shashak
02-20-2007, 12:54 AM
hey guys any comments (negative or positive), on my idea on this using mercury switch kind of system :) :) :)

vikas
02-20-2007, 01:07 AM
mercury switch will not work ... it will as a simple tilt sensor with on off capability but not in case of building a balancing robot.

madhooshah
09-10-2015, 10:13 AM
It depends upon your budget. Tell me expense i'll guide you.