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accelerometer to roll and pitch
Dave67 wrote: 1) Any attitude can be expressed in terms of Euler Angles - i.e. a series of rotations in the following non-commutative sequence: yaw (azimuth,theta, about y-axis...
Thursday, 16 February 2012 - 12:57
Interfacing a differential Sensor to a Differential ADC
Sorry for the late reply :( I was thinking something like the TI ADS1256. The rationale is that the sensors we are looking at have a noise specification of 5uV/rtHz, which, if we...
Sunday, 12 February 2012 - 12:13
accelerometer to roll and pitch
meslomp wrote:Damien, I see in your example program that you use the local gravity, but I guess that it can be left out of the formulas as it is always divided out in the end, is...
Sunday, 12 February 2012 - 05:29
accelerometer to roll and pitch
Let's assume we have perfect accelerometers, aligned perfectly with the vehicle's body frame and that we're perfectly stationary on the surface of the earth. We said before,...
Sunday, 12 February 2012 - 05:10
accelerometer to roll and pitch
Now, back to some theory :) A couple of posts ago, I said you can transform a vector quantity from one frame to another using a special 3x3 matrix: x_n = R_bn * x_b Where x_n...
Sunday, 12 February 2012 - 04:32
accelerometer to roll and pitch
Quote: In its current form, the output from my code would seem to still require a quadrant correction to be applied of: 0 - pitch for quadrant 1 ("Q1"); 180 - pitch for Q2 & Q3;...
Sunday, 12 February 2012 - 04:22
accelerometer to roll and pitch
Dave67 wrote:Hi Damien 1) I've used: pitch = atan2(ax,sqrt((ay*ay)+(az*az))) and roll = atan2(-ay,-sqrt((ax*ax)+(az*az))) instead of the simpler formulae of: pitch = atan2(ax,...
Sunday, 12 February 2012 - 04:17
accelerometer to roll and pitch
I think what we'll need to do is start from scratch. The first thing I'm going to do is define two coordinate systems. 1. The local navigation frame ("n-frame"). 2. The body-fixed...
Saturday, 11 February 2012 - 05:15
ADIS16060 (gyroscope) interfacing with ATMega32
WSNdemo wrote:The reading for 0 deg/sec is (0x1FFC) but it is not constant,its value is changing... MEMS gyros are quite noisy - you'll be getting something like 0.5 - 1.0deg/s...
Monday, 6 February 2012 - 07:45
ADIS16060 (gyroscope) interfacing with ATMega32
WSNdemo wrote:I am reading gyroscope data every 1ms. When I rotate the gyroscope, it doesn't change the reading. The interface is SPI. I have used software SPI. Remember, you'll...
Sunday, 5 February 2012 - 22:05
accelerometer to roll and pitch
Sorry for the late reply, but I have an answer for you :) Quote: I'm trying to find a way of using a 3-axis accelerometer output to measure "pitch" and "roll" over a full 360...
Monday, 30 January 2012 - 12:12
Valid reason to use unions with embedded systems.
Quote:Unions are often used by clever programmers to create job security and non-portable programs. I agree that the following is non-portable: static inline void...
Saturday, 17 December 2011 - 23:32