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Gyro / Tilt Sensor Question

Hi,

I've been reading up on RC helicopter gyros, and if I understand correctly they only measure one axis and are used to trim out unwanted yaw motion (rotation around the rotor shaft). For my application I need to sense rotation in the other two axis, roll and pitch (I'm not interested in yaw). Could I use two of these cheap piezo gyros mounted on their sides (rather than flat) to measure these axis?

The other problem is that these gyros will output a PWM signal to be fed into the servos, Ideally the sensor I want to use would output an analogue voltage depending on it's tilt angle. Can anyone point me in the right direction?

Cheers,

Jim

Reply to
Jim
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These guys

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have two-axis sensors that with analog outputs (roughly +1 to +4 with "level" corresponding to +2.5).

I've played with their SSY009XX series in a low dynamic rate application and was pretty happy with it. The response to a step change is fairly damped, which can be good in some applications, not so good in others. IIRC, the qty one price was about US$100.

Reply to
Rich Webb

Look at ADXL103 from Analog Devices..

"Jim" a écrit dans le message de news: snipped-for-privacy@f14g2000cwb.googlegroups.com...

Reply to
Fred*

try the following

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they have the kits & boards for the autopilot project at
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Lots of very good info about the sort of thing you want to do.

Regards, Rob>Look at ADXL103 from Analog Devices..

Reply to
robin.hartley

Thanks for your help guys, some interesting stuff there. With regards to the ADXL103 from Analog Devices, how can i buy one on it's own? I can only see pricing for 1000+ units. Incidentally, I just remembered that I've got an old Microsoft sidewinder freestyle pro in the loft that has been there for years. It is a game pad that responds (in analogue) to the direction you tilt it in. It is actually perfect for what I need, but if memory serves when plugged into the PC it drifted quite a lot. Cheep components I expect. Still, I'll open it up tonight and have a look at what is going on inside.

Jim

Reply to
Jim

You can try getting free samples directly from AD. You can also buy them retail from distributors like Digikey

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although they appear to be out-of-stock at the moment.

Reply to
Chris S.

I bought mine from Digikey, but

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usually has a similar MEMs accelerometer already mounted on a little PCB module for you to use. Digikey has the ADXL150 and ADXL250 accelerometer chips in stock still. The ADXL103 is really hard to get. AD has a little eval board for the MEMs chips too. If you want a nice MEMS Gyro the Analog Devices ADXRS series are really neat, Digikey numbers ADXRS150ABG-ND and ADXRS300ABG-ND and they have these in stock too. I did a
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Projects article about using the MEMs gyros and accelerometers a while back. Motorola/Freescale makes a nice MEMs accerometer as well, Digiikey number MMA1220D-ND a digikey search for freescale MMA turns up a bunch of hits and they have some of these in stock as well. There are some other MEMs chips under the Digikey number MSP1002-ND, MSP1004-ND , MSP1005-ND MSP6869-ND and MSP6870-ND Enjoy they are lots of fun.

Reply to
Earl Bollinger

try to ask a sample on AD website..

"Jim" a écrit dans le message de news: snipped-for-privacy@f14g2000cwb.googlegroups.com...

Reply to
Fred*

I'm not sure if I remember well, but there could be another reference of ADXL on Farnell catalog.. to be verified..

"Jim" a écrit dans le message de news: snipped-for-privacy@f14g2000cwb.googlegroups.com...

Reply to
Fred*

Try MEMSIC for samples as well. They have some very good dual-axis units and you can specify PWM or analog outputs.

Reply to
Bill Turnip

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