[Resolved]Unable to open I2C bus

[jawood]

Connected new BerryIMU to Raspberry Pi 2 with PiScreen on SanDisk Extreme 32Gig.

Installed piscreen image 1.8

raspi-config
– advanced settings – update – Expand file system – change password – change international settings – change host name – reboot

rpi-update
– reboot

apt-get update
apt-get upgrade
– reboot

sudo apt-get install i2c-tools libi2c-dev

sudo nano /etc/modules
– add i2c-dev, i2c-bcm2708

sudo nano /boot/config.txt
– add dtparam=i2c_arm=on, dtparam=i2c1=on
-reboot

sudo i2cdetect -y 1
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: — — — — — — — — — — — — —
10: — — — — — — — — — — — — — — 1e —
20: — — — — — — — — — — — — — — — —
30: — — — — — — — — — — — — — — — —
40: — — — — — — — — — — — — — — — —
50: — — — — — — — — — — — — — — — —
60: — — — — — — — — — — 6a — — — — —
70: — — — — — — — 77

git clone https://github.com/mwilliams03/BerryIMU.git

gcc compass_tutorial01.c -o compass_tutorial01 -lm

./compass_tutorial01
– Unable to open I2C bus!

P.S. Of course I still have the problem with the touch screen calibration too!

[Mark Williams]

Thanks for all the info.

Have you tried with ‘sudo’
sudo ./compass_tutorial01

Mark --OzzMaker.com --

[jawood]

🙂 that worked.

[jawood]

ok so that’s all good now moving onto the next issue…

Doing the compass calibration tutorial 03

Create text file with sudo ./compass_tutorial01 > rawdatauncalibrated.txt no problems

Remove first and last line with awk ‘NR>2{ print l} {l=$0}’ calnewtemp.txt > ~/uncalibrated.txt I get
– awk: 1: unexpected character 0xe2 (Even if I go into a text editor and remove 1st and last lines and any data that is not formatted correctly, I get the same error when running this command.)

[jawood]

rawdatauncalibrated.txt is the piped output
and
rawdatauncalibrated-1.txt is after I have manually edited the file and removed all erroneous data.
When run
awk ‘NR>2{ print l} {l=$0}’ calnewtemp.txt > ~/uncalibrated.txt
or
awk ‘NR>2{ print l} {l=$0}’ calnewtemp.txt > ~/uncalibrated-1.txt
get same error
awk: 1: unexpected character 0xe2

Attachments:

1. rawdatauncalibrated.txt
2. rawdatauncalibrated-1.txt

[jawood]

When trying to plot data with Mathematica

data = Import [“~/calibrated-1.txt”, “Table”, “FieldSeparators” -> {“,”, ” “}];
ListPlot[data[[All, {6, 9}]], AspectRatio -> 1, Frame -> True]

Import::nffil : File not found during import.

even if I do this

data = Import [“/home/pi/BerryIMU/compass_tutorial01_basics/calibrated-1.txt”, “Table”, “FieldSeparators” -> {“,”, ” “}];
ListPlot[data[[All, {6, 9}]], AspectRatio -> 1, Frame -> True]

[Mark Williams]

I tested the above syntax with your data and it works. See image below.

1.check the location of your data file
2.check the permissions on your data file

Mark --OzzMaker.com --

[jawood]

ok I got that to work now and can display un-calibrated plot graph.
when compiling compass_tutorial03.c after modifying calibration data I get error

pi@INS-RPi2-01 ~/BerryIMU/compass_tutorial03_calibration $ gcc -o compass_tutorial03 compass_tutorial03.c

/tmp/ccwU8pZV.o: In function `main’:
compass_tutorial03.c:(.text+0x354): undefined reference to `atan2′
collect2: ld returned 1 exit status

You were right though, it was just file name and paths incorrect.

[jawood]

Attached is copy of compass_tutorial03.c that I have after changing the calibration data variables.

Attachments:

1. compass_tutorial03.c

[Mark Williams]

compile with;
gcc -o compass_tutorial03_calibration compass_tutorial03_calibration.c -lm

-lm was missing on the instruction page.. sorry about that

Mark --OzzMaker.com --

[jawood]

thanks that’s got that sorted, now onto tutorial 4…

[jawood]

Ok so I dod the SDL install
sudo apt-get install libsdl1.2-dev libsdl-image1.2-dev libsdl-gfx1.2-dev libsdl-ttf2.0-dev

sudo nano test.c

copy

#include <SDL/SDL.h>

int main(int argc, char** argv) {
SDL_Init(SDL_INIT_EVERYTHING);
SDL_Surface *screen;

screen = SDL_SetVideoMode( 480, 320, 16, SDL_SWSURFACE );
SDL_Rect rect;
rect.x = 10;
rect.y = 10;
rect.w = 20;
rect.h = 20;

Uint32 color = SDL_MapRGB(screen->format, 0xff,0xff,0xff);
Uint32 color2 = SDL_MapRGB(screen->format, 0,0,0);
SDL_FillRect(screen, &screen->clip_rect, color);
SDL_Flip(screen);
getchar();

SDL_Quit();
return 0;
}

gcc -o test test.c sdl-config –cflags sdl-config –libs

Get error:-

Usage: sdl-config [–prefix[=DIR]] [–exec-prefix[=DIR]] [–version] [–cflags] [–libs] [–static-libs]
Usage: sdl-config [–prefix[=DIR]] [–exec-prefix[=DIR]] [–version] [–cflags] [–libs] [–static-libs]
/tmp/ccM8y3Uh.o: In function `main’:
test.c:(.text+0x18): undefined reference to `SDL_Init’
test.c:(.text+0x2c): undefined reference to `SDL_SetVideoMode’
test.c:(.text+0x6c): undefined reference to `SDL_MapRGB’
test.c:(.text+0x8c): undefined reference to `SDL_MapRGB’
test.c:(.text+0xa8): undefined reference to `SDL_FillRect’
test.c:(.text+0xb0): undefined reference to `SDL_Flip’
test.c:(.text+0xb8): undefined reference to `SDL_Quit’
collect2: ld returned 1 exit status

Ow and thanks for all your help so far

[Mark Williams]

link sdl by adding -lSDL to the end of the compile statement.

Mark --OzzMaker.com --

[jawood]

Thankyou again that got it going.
Now im doing the Inclinometer when I do this

gcc -o gyro_accelerometer_tutorial02 -lm gyro_accelerometer_tutorial02.c sdl-config –cflags sdl-config –libs -lSDL_image -lSDL_gfx

I get

Usage: sdl-config [–prefix[=DIR]] [–exec-prefix[=DIR]] [–version] [–cflags] [–libs] [–static-libs]
Usage: sdl-config [–prefix[=DIR]] [–exec-prefix[=DIR]] [–version] [–cflags] [–libs] [–static-libs]
gyro_accelerometer_tutorial02.c:25:17: fatal error: SDL.h: No such file or directory
compilation terminated.

[Mark Williams]

I am not near a Pi at the moment… but can you try again with -SDL at the end. Let me know how you go

Mark --OzzMaker.com --

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