From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261618AbVHAMVE (ORCPT ); Mon, 1 Aug 2005 08:21:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261844AbVHAMS5 (ORCPT ); Mon, 1 Aug 2005 08:18:57 -0400 Received: from [195.23.16.24] ([195.23.16.24]:26841 "EHLO bipbip.comserver-pie.com") by vger.kernel.org with ESMTP id S261877AbVHAMSv (ORCPT ); Mon, 1 Aug 2005 08:18:51 -0400 Message-ID: <42EE1324.10304@grupopie.com> Date: Mon, 01 Aug 2005 13:18:44 +0100 From: Paulo Marques Organization: Grupo PIE User-Agent: Mozilla Thunderbird 1.0 (X11/20041206) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Jan Engelhardt Cc: Lee Revell , abonilla@linuxwireless.org, linux-kernel@vger.kernel.org, hdaps devel , "'Yani Ioannou'" , Dave Hansen Subject: Re: IBM HDAPS, I need a tip. References: <1122861215.11148.26.camel@localhost.localdomain> <1122872189.5299.1.camel@localhost.localdomain> <1122873057.15825.26.camel@mindpipe> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Jan Engelhardt wrote: >>So in order to calibrate it you need a readily available source of >>constant acceleration, preferably with a known value. >> >>Hint: -9.8 m/sec^2. > > Drop it out of the window? :) No, no. Constant gravity (like having the laptop sitting on the desk) "feels like" constant acceleration. Dropping it out of the window should measure 0 m/sec^2, because the accelerometer is not working on an inertial referential (I hope this is the correct term in english...). For the accelerometer, this is just like the feeling of free falling inside an elevator: no gravity :) -- Paulo Marques - www.grupopie.com It is a mistake to think you can solve any major problems just with potatoes. Douglas Adams