Posts made by OSO Bear

Hello,

I'm using the Omega2s+ firmware: 0.3.2 b220 and am trying to interface with i2c to various devices. I am programming in C++. I've used the (libonioni2c.so) driver before for various writing operations (led drivers), but now want to use it for an ADC, which, oddly is the first time I've needed the 'read' functionality. When I run any code with the i2c_read function, the execution ends with a segmentation fault. I've recreated this on an Omega2+ as well.
I'm assuming this is the result of the Omega i2c driver trying to access some memory after this routine is complete? and it no longer existing? I've skimmed this example code down to the produce the error. This program runs all the way through, and after the very last line, return 0, produces the fault.

Why am I getting a segmentation fault? Do I need to close/kill/delete/freeup some bit of memory? Any thoughts?? Thank you!!!

#include <onion-i2c.h>
#include <chrono>
#include <thread>
#define I2C_DEF_ADPTR	    0 // Unique to Omega
#include <iostream>
using std::cout;  // For convienience
using std::endl;

int main()
{

  // register stuff

  cout << "Beginning..." << endl;
  int _address = 0x48;
  int status;
  uint8_t readValue[2];

  cout <<"About to start read..." << endl;

  status = i2c_read(  I2C_DEF_ADPTR, _address, 0x01, readValue, 2);

  cout << "Finished read... ";
  cout << "End of Program." << endl;

  std::this_thread::sleep_for(std::chrono::milliseconds(1000));  // << added this just in case i2c was slow to end process


  return 0;
}

Hello!

I'm trying to use the thread library from the c++11 std library (#include <thread>) . I am cross compiling on my linux machine which compiles fine with no errors or warnings. Once I transfer it to the Omega2+ (0.2.2 b200), I immediately get a runtime error. Using the ldd command I get this from the cross compiled version:

root@Omega-####:~/# ldd thread_test_01_CC_OO                                                                                                                                                                                                         
        /lib/ld-musl-mipsel-sf.so.1 (0x55a9e000)                                                                                                                                                                                                             
        libstdc++.so.6 => /usr/lib/libstdc++.so.6 (0x77598000)                                                                                                                                                                                               
        libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x77574000)                                                                                                                                                                                                     
        libc.so => /lib/ld-musl-mipsel-sf.so.1 (0x55a9e000)           
        Error relocating thread_test_01_CC_OO: _ZNSt6thread6_StateD2Ev: symbol not found                                                                                                                                                                             
        Error relocating thread_test_01_CC_OO: _ZNSt6thread15_M_start_threadESt10unique_ptrINS_6_StateESt14default_deleteIS1_EEPFvvE: symbol not found                                                                                                               
       Error relocating thread_test_01_CC_OO: _ZTINSt6thread6_StateE: symbol not found                                                                                                                                                                              
       Error relocating thread_test_01_CC_OO: _ZTINSt6thread6_StateE: symbol not found                                                                                                                                                                              
       Error relocating thread_test_01_CC_OO: _ZTINSt6thread6_StateE: symbol not found                                                                                                                                                                              
       Error relocating thread_test_01_CC_OO: _ZTINSt6thread6_StateE: symbol not found  

However, if I compile this code directly on the Omega, the code works completely fine, running the same command (ldd) as above lists the same dependencies except without any errors. I've checked my library versions as best I can, I've even started to copy the libraries from the Omega into my cross-compile staging directory but get the same results. Can anyone point me in the direction of how to solve this issue? Thank you!

// CPP program to demonstrate multithreading
// using three different callables.
#include <iostream>
#include <thread>
using namespace std;

// A dummy function
void foo(int Z)
{
    for (int i = 0; i < Z; i++) {
        cout << "Thread using function"
               " pointer as callable\n";
    }
}

// A callable object
class thread_obj {
public:
    void operator()(int x)
    {
        for (int i = 0; i < x; i++)
            cout << "Thread using function"
                  " object as  callable\n";
    }
};

int main()
{
    cout << "Threads 1 and 2 and 3 "
         "operating independently" << endl;

    // This thread is launched by using
    // function pointer as callable
    thread th1(foo, 3);

    // This thread is launched by using
    // function object as callable
    thread th2(thread_obj(), 3);

    // Define a Lambda Expression
    auto f = [](int x) {
        for (int i = 0; i < x; i++)
            cout << "Thread using lambda"
             " expression as callable\n";
    };

    // This thread is launched by using
    // lamda expression as callable
    thread th3(f, 3);

    // Wait for the threads to finish
    // Wait for thread t1 to finish
    th1.join();

    // Wait for thread t2 to finish
    th2.join();

    // Wait for thread t3 to finish
    th3.join();

    return 0;
}

Any luck figuring this out?

@Maximilian-Gerhardt wow! Thank you very much for your response, at least I don't have the feeling like I'm shouting into an empty cave!

I'm surprised at how beta the i2c library is for something that's been out for ~years. I feel like the first feature for boards like this (after GPIO control on its own pins) should be a matured and robust i2c library. Since, almost anything you want to do with them will require i2c communication...

Again, thank you for the heads up with known issues. I'll try to keep stumbling through this and if I succeed I'll make it available.

Since I already have a couple SX1509 GPIO expanders, I decided to make use of them with my Omega2 and wanted to port the Ardunio library over to work with the Omega to supporting all the board's features. (https://github.com/sparkfun/SX1509_IO-Expander)

I started on basically rerouting the read/write commands to the Omega's i2c_read/write functions but came across an issue I hadn't thought about. The Ardunio platform uses 'byte' (uint8_t) types which the omega doesnt. (unless I'm missing something?) I could try to find a way to continuously convert types back and forth, or, I was thinking just switching the code to replace 'byte' with 'int'

My question: if I switched everything to 'int' (like the onion_i2c libraries use), will I get unexpected behavior out of the code? Aside from memory size, does an int behave differently than the Ardunio's byte? Why does Arduino use bytes?

Thanks!

I'm new to this so please bear with me! (sorry I dont know how to insert code, help?)

I want to use the Omega2+ to compile C++ code and will be wanting to use (fast) GPIO read and write on the chip, i2c devices to control GPIO expanders (e.g.: MCP23017-E/SP) and an OLED. However I'm stuck at the 'Start' square.

I've followed the instruction set in the docs.onion.../cross-compiling and was able to get the (C) gpio example working - but will note, it was not mentioned you need to manually find, download and copy the header files into the appropriate directory.

Then, I tried the simplest possible 'hello world' C++ program. Ultimately, i was able to compile with the makefile below. Note: adding gpp vs. gcc, removing -l$(LIB) since I have no libraries. Copied the compiled file over to the Omega, chmod, ./helloworld,... and got something similar to:

/asd: line 1: syntax error: unexpected "(" (expecting ")")

So,.. is the Omega trying to interpret my compiled c++ code? why did this not work? Do I need to change some settings to have a different compiler run it (gpp vs gcc)? I've been bashing my head on this for so long I'm starting to get worried I'm over looking the obvious. Any help would be MUCH appreciated!!! Besides, I think having something well documented for how to run c++ would be very beneficial to the community

Assumption:

1. I will need to compile C++ code with customer headers for peripherals (e.g. sparkfun...)
2. I am running Linux Mint
3. Using Omega2+ v0.1.10
4. I've gone through cross-compile set up tutorial and can successfully run the example gpio C program.

. # main compiler
CXX := gpp #gpp for C++ or gcc for 'C'
CC := gcc #gpp for C++ or gcc for 'C'

.# Input (and) Output File name ("exe")
TARGET1 := Omega2_Test_GPIO

.# What does this do?
all: $(TARGET1)

$(TARGET1):
@echo "Compiling C program"
$(CXX) $(CFLAGS) $(TARGET1).cpp -o $(TARGET1) $(LDFLAGS)
#$(CC) $(CFLAGS) $(TARGET1).cpp -o $(TARGET1) $(LDFLAGS) #-l$(LIB)

clean:
@rm -rf $(TARGET1) $(TARGET2)