http://wiki.ukhas.org.uk/ 2008-12-01T19:33:05+00:00 http://wiki.ukhas.org.uk/ http://wiki.ukhas.org.uk/lib/images/favicon.ico text/html 2008-12-01T12:13:20+00:00 James Coxon http://wiki.ukhas.org.uk/projects:badger?rev=1228133600&do=diff BadgerWorks is an umbrella name for sub-projects for Cambridge University Spaceflight. We currently build the flight computers, called BadgerBoards. Missions * See the Cambridge University Spaceflight website for more information on these flights. text/html 2008-11-30T05:21:22+00:00 Laurence Blaxter http://wiki.ukhas.org.uk/code:optimised_kalman?rev=1228022482&do=diff This is optimised for use with GPS/rate gyro aided heading estimators. Reduced stack, flash and clock cycle use compared to the non optimised filter. Total runtime on atmega168 is 630us //Optimised Kalman filter code, all capitalised variables are filter parameters //x is the two component state vector, p is the covariance //propogator //x=F*x+B*u - u is single component control variable float a=F_A*x[0]+F_B*x[1]+(B_B*u); x[1]=F_C*x[0]+F_D*x[1]+(B_D*u); x[0]=a; //p=F*p*F'+Q … text/html 2008-11-30T00:50:38+00:00 Laurence Blaxter http://wiki.ukhas.org.uk/general:code?rev=1228006238&do=diff Here is source code for various languages that you may find useful in developing high altitude things. * Navigation * Bash script to rotate and GZIP log files * GPS emulator * Camera shutter trigger * octave datalogger code * kml near realtime update * Reed-Solomon encoder * NMEA collection * Interrupt driven TSIP parser for AVR * Interrupt driven NMEA parser for AVR * Two state Kalman Filter for parafoils and Rogallos * Optimised two state heading filtering Kalman filt… text/html 2008-11-28T03:32:57+00:00 Laurence Blaxter http://wiki.ukhas.org.uk/code:parafoil_tsip?rev=1227843177&do=diff Main.c //UAV parafoil main code //#define GROUND //comment\uncomment as you wish //#define EEPROM //put these in the makefile #include "main.h" //globals #ifdef GROUND volatile u16 diff; volatile u08 counter; #endif const char config_string[44] PROGMEM={0x10,0xBB,0x03,0x00,0x03,0x03,0x00,0x3D,0xB2,0xCA,0x58, 0x40,0x00,0x00,0x00,0x41,0x40,0x00,0x00,0x40,0xC0,0x00,0x00,0x1E,0x00,0x00,0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x10,0x03}; //new 0xBB packe… text/html 2008-11-27T18:38:13+00:00 Laurence Blaxter http://wiki.ukhas.org.uk/code:i2c_eeprom?rev=1227811093&do=diff I2Cmem.c #include "i2cmem.h" #ifdef EEPROM //----------General I2C functions------------------------------------------------------------------------- volatile u08 I2Cerr; void init_i2c() { TWBR=(u08)(((float)F_CPU/(2.0*(float)SCL))-8.0);//sets the correct clock rate defined as SCL } //we dont need to enable the hardware - its done in write void i2cstart() { u16 timeout=1; TWCR = (1<<TWINT)|(1<<TWSTA)|(1<<TWEN); //send start while (!(TWCR & (1<<TWINT)) && timeout); timeout++;… text/html 2008-11-25T00:24:35+00:00 Laurence Blaxter http://wiki.ukhas.org.uk/code:4_state_extended_kalman_filter_in_matlab?rev=1227572675&do=diff A few matlab scripts for attitude and hopefully (at some point) position estimation using MEMS sensors. The data used for tests was kindly recorded by a member of the sparkfun forum with a sparkfun 6DOF IMU. Ascii data is [here]. The format is time (seconds) roll pitch and yaw gyro rates, and x,y,z accel readings in g (roughly - obviously gain and bias need to be applied).