@cmelnick It's possible the onion-i2c:: debug readings aren't 100% correct. Can you try changing your code when you read to this: val = i2c.readBytes(0x5a, 0x5d, 1) print(val)

@Victor-Lucio Please take a look at this: Official Onion Omega2 Documentation I2C Python Module. '/usr/lib/python2.7/OmegaExpansion/onionI2C.so' is not empty - it's an ELF binary file. The source code can be found in the Onion i2c-exp-driver GitHub Repo. An example of how the onionI2C library is used can be found in the i2c-exp-driver repo. The example code programs the Relay Expansion (an MCP23008 8-bit, general purpose, parallel I/O expansion IC for I2C) directly. Good luck.

Thank you for responding, the real direction is 0x70 using 7 bits. In other words is 111-0000. If I include the bit of R/W, this will be 0 if i want to write a data in the slave(sensor). .111000-R/W ----------> 11100000 11100000 Is E0 in hex. For this reason, I have several concerns about this module, but I hope to solve it later. Thans again for taking my doubt. I will try to send you 6 bits as data and include the CRC byte. It is likely that when I insert the writeBytes command, the R/W bit is inclued internally without me noticing.

Thanks. I'd seen that before, ran into bigger problems with the pigpio build (eg no ldconfig available for the omega). That said, I found a method to use with the smbus2 package that allowed me what I needed.

It looks like this was an error in the library that I was using as the libraries author has confirmed they are seeing the same thing when they tried to read from the same kind of sensor.

readValue needs to be passed as a reference, since the contents will be modified by the i2c_read function. That's likely causing the segmentation fault. Or change readValue to a point and allocate two bytes before passing it to i2c_read See the documentation for the i2c_read function for more details: http://docs.onion.io/omega2-docs/i2c-c-library.html#i2c-c-read-multiple-bytes

@Matt-Gessner-0 while it is technically possible to do some development on the omega, it is quite impractical. You will quickly run out of capacity and patience and you'll end up using a more suitable build environment. Save youself the time and heartache. Take a look at the cross compiling docs it is easy to set up a build environment and use the better resources of a proper development platform

=== Version Info === Omega firmware: v0.2.1 b199 onion-os - 1.0.5-1

Wow, thank you so much! This is exactly what I was looking for.

If you have a build systen installed You can tweak the kernel setup by using "make kernel_menuconfig" Look under Device Drivers -> I2C Support, there is a several debugging options you can set in order to assist with debugging i2c.

With raspberry pi1 (the 2011 model) the screen are working but not with omega that not recognize them. I will probably resell my omega and various accessories because the assistance is not very helpful

@Michal-Dobrzynski Please do not forget to remove the pin3-pin4 short circuit if you want to plug the Oled Expansion to any genuine Onion Omega Expansion Board Header directly because Omega2(+) may be damaged if you set GPIO11 to Low. There are I2C level shifters on the OLED Expansion. Pin4 of the Expansion Header provides the voltage to the lower voltage section for those level shifters. But pin4 of the Expansion Header is connected to GPIO11 on the Omega2(+) board. So @Onion must set GPIO11 to High (~3.3V). It's a hidden simple hack that @Onion forgot to mention for example here. You could find some further technical details here.

@Maximilian-Gerhardt Thank You. I have been fighting against an error where it looked like the linker was not finding my the shared libonioni2c.so. Your suggestion about first renaming the current files /usr/lib/libonioni2c.so to /usr/lib/libonioni2c.so.XX and /usr/lib/liboniondebug.so to /usr/lib/liboniondebug.so.XX was a good suggestion. My error changed to libonioni2c.so not found. So it shows me the linker was finding the correct shared object but there was something wrong with that libonioni2c.so share object. then I copied the shared objecs from github https://github.com/gamer-cndg/omega2-libs and put them in /usr/lib and everything worked!!! 2 weeks I have wasted. Now I don't know what is in those shared objects or what is different but at least I can continue building my project. From my 2 weeks of trying everything I have concluded that the shared object libraries provided in the standard distribution for the 2+ libonioni2c.so and/or liboniondebug.so are defective.

Sorry, my fault 194 is ok!