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Re: GM862-GPS REBOOT when an error occurs

 by sfe_kav ¦  Mon Jun 20, 2011 8:28 pm ¦  Forum: GPS ¦  Topic: GM862-GPS REBOOT when an error occurs ¦  Replies: 1 ¦  Views: 565

try to use watchdog timer.

set watchdog timer for N seconds;

in unconditional state of python script run infinite loop
so script hangs and watchdog reboot module

but if there are bug in script - debug and fix it.

Re: 9DOF Razor IMU AHRS - what some constants mean?

 by sfe_kav ¦  Fri May 13, 2011 9:41 pm ¦  Forum: SparkFun Product Questions ¦  Topic: 9DOF Razor IMU AHRS - what some constants mean? ¦  Replies: 12 ¦  Views: 2319

)))) 1/256 == 0.0039
my english is vary bad))) its the same value but inverted)))


in first post about adxl345:
[remove]bias=1/256[/remove] gain=1/256
bias = 0

Re: 9DOF Razor IMU AHRS - what some constants mean?

 by sfe_kav ¦  Fri May 13, 2011 9:36 pm ¦  Forum: SparkFun Product Questions ¦  Topic: 9DOF Razor IMU AHRS - what some constants mean? ¦  Replies: 12 ¦  Views: 2319

sorry))))

for adx345 read scale line from specification
for +-2G 10 bit resolution mode scale=3.9mG/LSB ==0.0039G/LSB
so gain=scale=0.0039 )))

here is tutorial for adxl345 http://www.sparkfun.com/tutorials/240

Re: 9DOF Razor IMU AHRS - what some constants mean?

 by sfe_kav ¦  Fri May 13, 2011 9:19 pm ¦  Forum: SparkFun Product Questions ¦  Topic: 9DOF Razor IMU AHRS - what some constants mean? ¦  Replies: 12 ¦  Views: 2319

for adxl335 gain is (from specification line about SENSITIVITY 300mV/G == 0.3V/G) so gain will be 3.3V/(0.3V*1023) For adxl345 you read digital values from sensor sensitivity in specification pointed in LSB/G (lowerest significant bit/G) so for +-2G measurement range and 10 bit resolution sensitivit...

Re: 9DOF Razor IMU AHRS - what some constants mean?

 by sfe_kav ¦  Fri May 13, 2011 6:45 am ¦  Forum: SparkFun Product Questions ¦  Topic: 9DOF Razor IMU AHRS - what some constants mean? ¦  Replies: 12 ¦  Views: 2319

sorry.

bias=1.5V/5V*1023
gain=5V/(0.5V*1023)

Re: 9DOF Razor IMU AHRS - what some constants mean?

 by sfe_kav ¦  Fri May 13, 2011 6:25 am ¦  Forum: SparkFun Product Questions ¦  Topic: 9DOF Razor IMU AHRS - what some constants mean? ¦  Replies: 12 ¦  Views: 2319

bias == zero value A=(ADC_VAL-BIAS)*GAIN where A - is acceleration(m\c^2) or angular velocity(deg/s) or gauses ADC_VAL - value from analog to figital converter (for arduino in range 0-1023) BIAS -zero value GAIN proportial coefficient to convert adc value to phisical units(acceleration, ang. velocit...

Re: Home-made autopilot

 by sfe_kav ¦  Sun Mar 20, 2011 5:12 am ¦  Forum: SparkFun Product Questions ¦  Topic: Home-made autopilot ¦  Replies: 1 ¦  Views: 934

heh 3 attachments limit)))

DSC00542.JPG
Yes, it was my first board with smd))

page with full set of images(but in russian) http://tamila.linux-rusnet.org/dla-istorii

Home-made autopilot

 by sfe_kav ¦  Sun Mar 20, 2011 5:00 am ¦  Forum: SparkFun Product Questions ¦  Topic: Home-made autopilot ¦  Replies: 1 ¦  Views: 934

Want to build your own autopilot? it`s vary easy. So what steps to do autopilot ? I go along this plan: 1. Idea to build autopilot. 2. Read Internet about same projects, what sensors thay use. read more the better))) 3. Select sensors and hardware platform you whant to use (I select Arduino Mega(128...

Re: Multiple I2C devices

 by sfe_kav ¦  Mon Feb 14, 2011 10:16 am ¦  Forum: Arduino ¦  Topic: Multiple I2C devices ¦  Replies: 4 ¦  Views: 1823

if you use level coverter than you dont need pullups, just look on schematics http://www.sparkfun.com/datasheets/BreakoutBoards/Level-Converter-v10.pdf There are pulups(R3 R4) on both sides))) >> If the 3V3 device is sharing the I2C channel with a 5V device, do I need pullups on both device's SCL an...

Re: 9DOF Razor IMU AHRS - what some constants mean?

 by sfe_kav ¦  Mon Nov 29, 2010 9:31 am ¦  Forum: SparkFun Product Questions ¦  Topic: 9DOF Razor IMU AHRS - what some constants mean? ¦  Replies: 12 ¦  Views: 2319

sebmadgwick, thanks.

Very helpfull for me.

Re: 9DOF Razor IMU AHRS - what some constants mean?

 by sfe_kav ¦  Sun Nov 28, 2010 1:10 pm ¦  Forum: SparkFun Product Questions ¦  Topic: 9DOF Razor IMU AHRS - what some constants mean? ¦  Replies: 12 ¦  Views: 2319

yes this is proportional and integral constants for drift coorection, but what they mean?))) (elefant)/(monkey square)?))

9DOF Razor IMU AHRS - what some constants mean?

 by sfe_kav ¦  Sun Nov 28, 2010 6:55 am ¦  Forum: SparkFun Product Questions ¦  Topic: 9DOF Razor IMU AHRS - what some constants mean? ¦  Replies: 12 ¦  Views: 2319

Hello, I am porting algorithm from http://code.google.com/p/sf9domahrs/ to my device I have angular velocity measured in rad/s, acceleration in G units (1==9.8m/sec^2), and magnetic field in units of earth mag. field Is anybody know physical and/or mathematical meaning of these four coefficient: #de...

Re: I can not program Arduino Pro Mini

 by sfe_kav ¦  Fri Aug 06, 2010 2:26 am ¦  Forum: AVR Microcontrollers ¦  Topic: I can not program Arduino Pro Mini ¦  Replies: 4 ¦  Views: 3671

without FTDI you can use any usb->serial: connect rx,tx,ground and power(3.3V or 5V) before programming press reset button and than very fast as posible program your mini using IDE you has less than 1 second after pressing reset button. dtr signal of ftdi connected to reset, so you can start bootloa...

Re: I can not program Arduino Pro Mini

 by sfe_kav ¦  Tue Jul 20, 2010 6:42 am ¦  Forum: AVR Microcontrollers ¦  Topic: I can not program Arduino Pro Mini ¦  Replies: 4 ¦  Views: 3671

you need connecting DTR pin of usb serial to pro-mini and all will be ok.
Look at FTDI bassic brakeout from SF it hase same pinout as pro-mini.

Re: programming arduino duemilanove via avrdude

 by sfe_kav ¦  Tue Jul 20, 2010 4:30 am ¦  Forum: AVR Microcontrollers ¦  Topic: programming arduino duemilanove via avrdude ¦  Replies: 1 ¦  Views: 1984

solved))) it was problem in linking and building hex file with makefile like: all: sample.hex sample.o: sample.c avr-gcc -c -g -Os -w -ffunction-sections -fdata-sections -mmcu=atmega328p -DF_CPU=16000000L sample.c sample.elf: sample.o avr-gcc -Os -Wl,--gc-sections -mmcu=atmega328p -osample.elf sampl...