Posts made by will burke

@Kit-Bishop

The code successfully runs and I receive the correct data. I can verify this by breaking my loopback on the MISO/MOSI pins and also by watching those pins on a scope.

section of output from running code on the onion:
Communication send 0x55
SC18IS602::transfer buf 55
SC18IS602::WriteBytes buf U len 1
SC18IS602::ReadBytes buf U len 1
SC18IS602::transfer rec 55
aa
Rec: 55
Communication send 0xAA
SC18IS602::transfer buf aa
SC18IS602::WriteBytes buf ▒ len 1
SC18IS602::ReadBytes buf ▒ len 1
SC18IS602::transfer rec aa
aa
Rec: aa
Communication is good
Aborted

I have zipped up the source code and I'm using "build_test1" to generate the code

i2c_spi_bridge_2016-03-03.zip

@Kit-Bishop

I now have my code compiling and running. I successfully configure the I2C to SPI Bridge.

As a first test I'm sending/receiving 0x55 and 0xAA bytes on the SPI bus. I looped MOSI to MISO so that I receive the data sent. This is working, however after successfully running and transmitting all bytes of data the program aborts. Could this abort be caused by the static vs dynamic linking that you are talking about?

Figured It out, the IO is correct. My issue was I did not have the required pullup resistors on the I2C lines.

According to the documentation the I2C pins on the Omega are shared with the GPIO pins 20 and 21. Is this correct?

When I try the i2c-tools I don't see any switching on pins 20 or 21. When I use the fast-gpio on pins 20 and 21 the IO responds correctly.

Is there something I need to change to switch the pins functionality? Or am I looking at the wrong IO pins?

@Kit-Bishop

Thanks for the help. That was the issue. I had to include the src files from src/lib/onion-i2c.c and src/lib/onion-debug.c. The section on using the library was not completely clear and I assumed the header was just for reference the functions in the library.

https://wiki.onion.io/Tutorials/Libraries/I2C-Library#the-c-library_using-the-library

Header File

To add the Onion I2C Library to your C/C++ program, include the header file in your C code:

#include <onion-i2c.h>

Library for Linker

In your project's makefile, you will need to add the following static libraries to the linker command:

-loniondebug -lonioni2c

The static libraries are stored in /usr/lib on the Omega.

That is most likely the issue. I'm trying to use the i2c library. What I really need is spi but I'm io limited so I can't just Bit Bang spi on the gpio. I need to use the i2c to spi bridge. I just assumed I was linking to the correct .so with those functions, it appears that I'm not.

@Kit-Bishop,

Thanks for the tips. I have compiled and successfully tested on the Omega using the separate copy of the toolchain as you describe.

I'm on to my next issue. I'm trying to use the I2C library:
https://wiki.onion.io/Tutorials/Libraries/I2C-Library

I copied over the libonioni2c.so from the onion and am trying to link to the .so. However when I call the i2c_ functions they are still undefined references.

Command:
mips-openwrt-linux-uclibc-g++ -O2 -fPIC -L./omega_libs -lonioni2c -loniondebug -I./i2c-exp-driver-master
/include i2c_spi_bridge.c SC18IS602.cpp -o test1

Output:
/tmp/cc4spNYj.o: In function SC18IS602::WriteBytes(unsigned char*, unsigned char)': SC18IS602.cpp:(.text+0x2c): undefined reference to i2c_writeBuffer'
/tmp/cc4spNYj.o: In function SC18IS602::ReadBytes(unsigned char*, unsigned char)': SC18IS602.cpp:(.text+0x80): undefined reference to i2c_read'
/tmp/cc4spNYj.o: In function SC18IS602::ReadByte()': SC18IS602.cpp:(.text+0x198): undefined reference to i2c_readByte'
/tmp/cc4spNYj.o: In function SC18IS602::WriteRegister(unsigned char, unsigned char)': SC18IS602.cpp:(.text+0x1f4): undefined reference to i2c_write'
collect2: error: ld returned 1 exit status

I have never used the OpenWRT tool chain. It took me a bit to get the cross compile setup to a point where I think its working on an ubuntu system.

I followed the steps from
https://wiki.onion.io/Tutorials/Cross-Compile

I setup a new package that's currently just a hello world example but will become an I2C to SPI library to use an SC18IS602 I2C to SPI converter (http://www.nxp.com/documents/data_sheet/SC18IS602B.pdf)

When I build my new test package:
$ make package/i2c_spi_bridge/compile
make[1] package/i2c_spi_bridge/compile
make[2] -C package/libs/toolchain compile
make[2] -C package/i2c_spi_bridge compile

so building appears fine but I can't tell where the compiled code is located, where did it go?

I then compiled directly calling a gcc from the staging_dir/toolchain directory, not sure if this is the correct one but the code did compile. Is this the correct gcc to use?

../../../staging_dir/toolchain-mips_34kc_gcc-4.8-linaro_uClibc-0.9.33.2/bin/mips-openwrt-linux-uclibc-gcc i2c_spi_bridge.c -o test

I haven't tested this yet because the onion is on a different wireless network then I'm on, but is hooked up to this machine using the usb port. Is there a way for me to send a file to the onion using the usb port?