angle/direction sensing (was Memsic sensor and rotation)
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Posts: 46,084
Hi,
I'm looking for a way to sense the direction that my robot is facing (Yaw).
I've been looking at a couple of gyroscopes online, but the cost and wait
time (2 months) are prohibitive. These are Murata's Gyrostar, and Analog
Device's ADXRS150-EB (the evaluation board). Both seem pretty interesting
giving a reading of acceleration as your bot turns, which you should be able
to integrate to get velocity and angle.
This area is new to me so perhaps I'm overlooking an economical method for
figuring out the angle. I have other accelerometers in the circuit from
which linear velocity and distance is gathered in both x and y directions,
as well tilt in x and y (using the memsic ic). Perhaps there's some trig
function that derive's Yaw from these other properties?
Alternatively does anyone know of any other more affordable gyros. There's a
nuts and volts article on Austria Microsystem's AS5020 but if I understand
it correctly you need to have a fixed magnet or metal object close by as a
reference point?
Cheers,
nick
I'm looking for a way to sense the direction that my robot is facing (Yaw).
I've been looking at a couple of gyroscopes online, but the cost and wait
time (2 months) are prohibitive. These are Murata's Gyrostar, and Analog
Device's ADXRS150-EB (the evaluation board). Both seem pretty interesting
giving a reading of acceleration as your bot turns, which you should be able
to integrate to get velocity and angle.
This area is new to me so perhaps I'm overlooking an economical method for
figuring out the angle. I have other accelerometers in the circuit from
which linear velocity and distance is gathered in both x and y directions,
as well tilt in x and y (using the memsic ic). Perhaps there's some trig
function that derive's Yaw from these other properties?
Alternatively does anyone know of any other more affordable gyros. There's a
nuts and volts article on Austria Microsystem's AS5020 but if I understand
it correctly you need to have a fixed magnet or metal object close by as a
reference point?
Cheers,
nick
Comments
compass with some sensors and read out the position from it.
jim
http://www.geocities.com/jimforkin2003/
Original Message
From: nick stedman [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=As4kACs1t7qYzoZi9G2j47cT8ylld31gpCgchdtXeoPVaPNJqMxTEgN1E5oik27_QW8KcDMC-6uPeqP8axWyHpZF]nickstedman@s...[/url
Sent: Tuesday, September 16, 2003 12:03 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] angle/direction sensing (was Memsic sensor and
rotation)
Hi,
I'm looking for a way to sense the direction that my robot is facing (Yaw).
I've been looking at a couple of gyroscopes online, but the cost and wait
time (2 months) are prohibitive. These are Murata's Gyrostar, and Analog
Device's ADXRS150-EB (the evaluation board). Both seem pretty interesting
giving a reading of acceleration as your bot turns, which you should be able
to integrate to get velocity and angle.
This area is new to me so perhaps I'm overlooking an economical method for
figuring out the angle. I have other accelerometers in the circuit from
which linear velocity and distance is gathered in both x and y directions,
as well tilt in x and y (using the memsic ic). Perhaps there's some trig
function that derive's Yaw from these other properties?
Alternatively does anyone know of any other more affordable gyros. There's a
nuts and volts article on Austria Microsystem's AS5020 but if I understand
it correctly you need to have a fixed magnet or metal object close by as a
reference point?
Cheers,
nick
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Acroname. I've used it with BASIC Stamps and the Javelin Stamp.
-- Jon Williams
-- Applications Engineer, Parallax
-- Dallas Office
Original Message
From: nick stedman [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=pGYGLOuiM6b_upwImlReRaYVt-ZEZiu9ZMN8Llv5tpH1wCiNL1atjcuMzE3Z4uTJOQ5NWIsjExGpd-Ubl78]nickstedman@s...[/url
Sent: Tuesday, September 16, 2003 11:03 AM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] angle/direction sensing (was Memsic sensor and
rotation)
Hi,
I'm looking for a way to sense the direction that my robot is facing
(Yaw). I've been looking at a couple of gyroscopes online, but the cost
and wait time (2 months) are prohibitive. These are Murata's Gyrostar,
and Analog Device's ADXRS150-EB (the evaluation board). Both seem pretty
interesting giving a reading of acceleration as your bot turns, which
you should be able to integrate to get velocity and angle. This area is
new to me so perhaps I'm overlooking an economical method for figuring
out the angle. I have other accelerometers in the circuit from which
linear velocity and distance is gathered in both x and y directions, as
well tilt in x and y (using the memsic ic). Perhaps there's some trig
function that derive's Yaw from these other properties? Alternatively
does anyone know of any other more affordable gyros. There's a nuts and
volts article on Austria Microsystem's AS5020 but if I understand it
correctly you need to have a fixed magnet or metal object close by as a
reference point? Cheers, nick
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Both gyro chips that you mention produce angular velocity directly, not
angular acceleration. Integrating velocity to produce position has the
problem that any DC offsets also get integrated, producing a ramp in
position, which acts as a drift error. Have you considered a digital
compass circuit instead, which would give an absolute reference for
direction?
Dennis
Original Message
From: nick stedman [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=uDXtW5F26L3ThhbqDEXp9R4H5xJdzPSTB0Rp16zYdMqWh5ZovQQPIX3HDds63mb22ssC9qdZ9Pe1dyTuWLLHUaHwIw]nickstedman@s...[/url
Sent: Tuesday, September 16, 2003 9:03 AM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] angle/direction sensing (was Memsic sensor and
rotation)
Hi,
I'm looking for a way to sense the direction that my robot is facing
(Yaw). I've been looking at a couple of gyroscopes online, but the cost
and wait time (2 months) are prohibitive. These are Murata's Gyrostar,
and Analog Device's ADXRS150-EB (the evaluation board). Both seem pretty
interesting giving a reading of acceleration as your bot turns, which
you should be able to integrate to get velocity and angle. This area is
new to me so perhaps I'm overlooking an economical method for figuring
out the angle. I have other accelerometers in the circuit from which
linear velocity and distance is gathered in both x and y directions, as
well tilt in x and y (using the memsic ic). Perhaps there's some trig
function that derive's Yaw from these other properties? Alternatively
does anyone know of any other more affordable gyros. There's a nuts and
volts article on Austria Microsystem's AS5020 but if I understand it
correctly you need to have a fixed magnet or metal object close by as a
reference point? Cheers, nick
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It's amazing, I had been searching for digital compasses at Digikey and only
found ones that cost a minimum of $500. But I overlooked the simple google
search. These look interesting...<http://www.dinsmoresensors.com/>. Anyway,
I decided to go with the devantech compass, because I've been happy with
their other sensors. Also, the retailer is in my city, so I won't need to
wait very long to get it.
Cheers,
Nick
on 09/16/03 1:11 PM, Jon Williams at jwilliams@p... wrote:
> You might consider the Devantech CMPS01 compass that is available from
> Acroname. I've used it with BASIC Stamps and the Javelin Stamp.
>
> -- Jon Williams
> -- Applications Engineer, Parallax
> -- Dallas Office
>
>
>
Original Message
> From: nick stedman [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=qJAS5P7aTaAZaRTFGSgrjneye4lKoT7LjLyEUq-ofQjISw1958gUzKeD1UMMGWDgPqU6g1Lkcp4mppaeDI1QR3l9Wg]nickstedman@s...[/url
> Sent: Tuesday, September 16, 2003 11:03 AM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] angle/direction sensing (was Memsic sensor and
> rotation)
>
>
> Hi,
> I'm looking for a way to sense the direction that my robot is facing
> (Yaw). I've been looking at a couple of gyroscopes online, but the cost
> and wait time (2 months) are prohibitive. These are Murata's Gyrostar,
> and Analog Device's ADXRS150-EB (the evaluation board). Both seem pretty
> interesting giving a reading of acceleration as your bot turns, which
> you should be able to integrate to get velocity and angle. This area is
> new to me so perhaps I'm overlooking an economical method for figuring
> out the angle. I have other accelerometers in the circuit from which
> linear velocity and distance is gathered in both x and y directions, as
> well tilt in x and y (using the memsic ic). Perhaps there's some trig
> function that derive's Yaw from these other properties? Alternatively
> does anyone know of any other more affordable gyros. There's a nuts and
> volts article on Austria Microsystem's AS5020 but if I understand it
> correctly you need to have a fixed magnet or metal object close by as a
> reference point? Cheers, nick
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
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> and Body of the message will be ignored.
>
>
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> http://docs.yahoo.com/info/terms/
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>
>
>
> This message has been scanned by WebShield. Please report SPAM to
> abuse@p....
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>
> To UNSUBSCRIBE, just send mail to:
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