Fred 453 Posted March 11, 2013 Share Posted March 11, 2013 Some really useful stuff. I started playing around with the same (or very similar) IMU but didn't get as far before getting sidetracked on other stuff. When I get back to it I'll definitely take a look at your code as a starting point. Unless I decide that the STM32F3 discovery kit (with onboard IMU components and ridiculously low price) is a better fit. Quote Link to post Share on other sites
aBUGSworstnightmare 1 Posted March 11, 2013 Share Posted March 11, 2013 Some really useful stuff. I started playing around with the same (or very similar) IMU but didn't get as far before getting sidetracked on other stuff. When I get back to it I'll definitely take a look at your code as a starting point. Unless I decide that the STM32F3 discovery kit (with onboard IMU components and ridiculously low price) is a better fit. Well, don't be surprised when you'll find out that the ACC on the STM32F3 kit isn't the best one out there in the market. You should have a look at 'baseflight' when you want to stay with the STM part. Quote Link to post Share on other sites
Terenceang 0 Posted March 12, 2013 Author Share Posted March 12, 2013 I tot of STMF32F3, similar setup as the PX4, maybe easier to port.. @Fred, if you have time to look at the code, I am getting running error on the Roll axis, and after fixing the update rate to 100Hz. I am getting some scaling error. I will look at it again this week end. Quote Link to post Share on other sites
Darmurg 0 Posted March 12, 2013 Share Posted March 12, 2013 https://code.google.com/p/stellaris-lp-imu/source/browse/#svn%2Ftrunk%2Fstellaris-lp-imu the code is for UART1. not updated to use the UI. Please update us with you mocap experiment, thanks. just cloned the repository, thank you. I'm waiting for the sensor modules, when they will arrive I will try your code and start the developement Quote Link to post Share on other sites
Terenceang 0 Posted March 12, 2013 Author Share Posted March 12, 2013 @Darmurg, you might want to check this out. runs ont the 430. http://invensense.com/mems/gyro/documents/PB-MPU-9150IMF%20MotionFit%20Wireless%20Developer%20Kit%20Product%20Brief.pdf Quote Link to post Share on other sites
Darmurg 0 Posted March 12, 2013 Share Posted March 12, 2013 I'll take a look, thanks! Quote Link to post Share on other sites
jon1426459908 0 Posted March 12, 2013 Share Posted March 12, 2013 @Fred, if you have time to look at the code, I am getting running error on the Roll axis, and after fixing the update rate to 100Hz. I am getting some scaling error.I will look at it again this week end. Is it stable before the Euler conversion? http://www.diydrones.com/forum/topics/madgwick-imu-ahrs-and-fast-inverse-square-root http://stackoverflow.com/questions/5577334/strange-behavior-with-android-orientation-sensor/5578867#5578867 Terenceang 1 Quote Link to post Share on other sites
Terenceang 0 Posted March 13, 2013 Author Share Posted March 13, 2013 thanks now i understand it better.. Is it stable before the Euler conversion? http://www.diydrones.com/forum/topics/madgwick-imu-ahrs-and-fast-inverse-square-root http://stackoverflow.com/questions/5577334/strange-behavior-with-android-orientation-sensor/5578867#5578867 Quote Link to post Share on other sites
Terenceang 0 Posted March 13, 2013 Author Share Posted March 13, 2013 eliminated the inverse sqaure root issue. 1.0f / sqrtf(x) instead. 104 cycles with fpu, 150 cycles without fpu, 107 with fast invsqrt routine. Quote Link to post Share on other sites
Terenceang 0 Posted March 13, 2013 Author Share Posted March 13, 2013 ok, everything is working fine, except some how after the fix, pitch and roll is mixing into each other's axis. rechecking all the axis. Quote Link to post Share on other sites
timotet 44 Posted March 13, 2013 Share Posted March 13, 2013 @pentiumpc Don't want to get off topic, but how do you get the cycle count? Nice work on the IMU! thanks Tim Quote Link to post Share on other sites
Terenceang 0 Posted March 14, 2013 Author Share Posted March 14, 2013 Hi Tim, add an event counter in the breakpoint window and set breakpoint between the instructions you want to count, enable and disable the counter to reset. you can find the instructions in the FPU lab segment in the Stellaris tutorial, Cheers, Terence. timotet 1 Quote Link to post Share on other sites
Terenceang 0 Posted March 14, 2013 Author Share Posted March 14, 2013 the IMU is working and pretty stable. but the motion seem to have some dampening effect at the end, if you bank 45 degrees, it will go to 40 degree then slowly go to 45... have to study more to figure out why.. maybe the sampleing rate or some time related maths. code is updated!! bluehash 1 Quote Link to post Share on other sites
Darmurg 0 Posted April 17, 2013 Share Posted April 17, 2013 Finally my GY-80 boards are arrived from china , I'm still waiting for bluetooth modules but now I can start working. I will try them with your code to test if they are working or faulty, then I will start to study your code and then modify it or write my own one. I've downloaded last version from your repository (r11) and successfully imported the project into CCS. How can I test if my setup is working after compiling the code? Have I to set something into project options? These are the connections from Stellaris board to GY-80 board: Stellaris VBUS -> GY-80 VCC_IN Stellaris GND -> GY-80 GND Stellaris PA6 -> GY-80 SCL Stellaris PA7 -> GY-80 SDA bluehash 1 Quote Link to post Share on other sites
Darmurg 0 Posted April 19, 2013 Share Posted April 19, 2013 It works! time to study!!! Terenceang, chicken and bluehash 3 Quote Link to post Share on other sites
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