Memsic Tilt sensor - I have a question

SN96

Hello guys,

I want to make a humanoid biped·but was wondering if I can get left and right tilt sensing with the memsic sensor mounted virtical, not flat. As an example of what I am talking about is mounting the memsic on the homework board, and then standing the homework board on it's edge. Due to limited space, the board needs to be·mounted on the back vertically. I would assume that this·would give me rotation axis sensing, but as long as I can take the rotation readings and code it to react to left or right tilt, thats all I would need it to do. I want to have my bot be able to avoid falling over from the left or right and not so much falling over forward or backward.

Thanks for any help you can provide.

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Mike



·

Ken Gracey

Mike,

Yes, you can do exactly that.

See http://www.parallax.com/dl/docs/prod/acc/memsickit.pdf experiment #2 for an example. Took me a while to find it since we've published so much documentation on this sensor.

When you're done with the humanoid (or after you get started) please share your experiences with us!

Ken Gracey
Parallax, Inc.

SN96

I am a bit confused with the two different schematics of·the memsic sensor. I have designed a carrier board to mount the memsic sensor, and right now, the traces I have are based off the memsic·screenshot PDF·called tilt1.pdf. In this screen shot taken from the documentation, it shows pin 1 & 4 of the memsic not being used, and 220 ohm resistors used for the X/Y outputs.

In the tilt2.pdf screenshot, it shows pin one and pin four being used. Pin one as T out and pin 4 to ground. This configuration is also not using the 220 ohm resistors for the X/Y outputs. I looked in the documentation, and in the·code example, and I did not see where pin 1 was being referanced in the code. What does T out do?

>>EDIT<<
I found out wht the T out is used for, at the very bottom of the last page it explains that T out is used for temperature feedback of the memsic. I still need to figure out if the pin#4 ground is needed, or if it is only used for the T out feature. I also still need to figure4 out if the 220 ohm resistors are needed for the X/Y outputs.
>>End Edit<<


I just need to figure out what configuration I need to use for rotational sensing. If I need to use the configurarion in the tilt2.pdf example, then I will need to revise my curcuit board design.

Thanks Again

·

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Mike





Post Edited (SN96) : 4/29/2006 1:25:54 PM GMT

Chris Savage

Mike,

·· The only difference between the two schematics is that in one the T Out is not being used and the extra Vss line is not connected.· So if you're not using T Out then there's nothing to worry about.· Either will work.· You can either connect T Out or not.· It depends on whether your code uses it or not.

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Chris Savage
Parallax Tech Support
csavage@parallax.com