Dereference a pointer

This is hopefully the last question on this topic. In C, arrays are zero based and in Julia they are 1 based. Is that going to make a difference when getting values back in a buffer (i.e. Vector) from these ccall function calls?

You need to use the correct syntax on both side to access a specific element but other than that the difference between the two language does not affect how you write the interface code.

OK. I just wanted to double check.

Can you post the code for this? I’ve been meaning to do this to get the accelerometer working for SenseHat.jl.

Hi Simon. I’ll try to post what I’m working on to my github. It probably won’t be until Monday (sorry). I saw on your site that it looks like you tried to go down the same route I did with converting the i2c-dev.h to Julia. I got nowhere with that. I was told that Julia didn’t have an equivalent to the C union. So, I have just made a shared library out of i2c-dev.h (made it a C file and stripped the ā€œstatic inlineā€ from the front of each function). Then, I made a Julia wrapper module to go against that. I have to come up with a way to deploy it so it will compile the source into the shared library on the source machine. My ideas are kind of trying to think ā€œbig pictureā€ - for different linux based development boards - not just the Pi. Since, they all do GPIO the same through the file system and all do i2c basically the same. You can look at the idea at:

https://github.com/fapplin/Julia_On_Development_Boards

This is something I would like to present at the next Julia conference and maybe present at a Pi conference. I’ll try to get you the code up on this site by the end of the day, but I think you get the gist of what I did.

The files are on my github site. I was trying to make the Julia_I2C module more self-contained, but I just couldn’t get it to work. So, what worked is up there.