Why the previous problem isn't written anywhere? So many tutorials, so many books, but I 'discovered' it by accident when I tried to figure out how one library was working. What does this '&' after Wire.read() REALLY means? (I know that it points to option within register, but I do not really understand this, why is it there) To read only option 3, I would use this code: Wire.beginTransmission(module_address) īyte readings = Wire.read() & 0x1F //0x1F is hexadecimal of binary 0001111 for option 3 in register 1 For example, lets say that imaginary module has First read register like this:ĪDDRESS | BIT 7 | BIT 6 | BIT 5 | BIT 4 | BIT 3 | BIT 2 | BIT 1 | BIT 0ĭata Byte1 | mute. Usually, every register has more than one 'option' inside.

So far, working with ANY module I got, it was NEVER that easy. Wire.write(something) //write to second register Wire.write(something) //Write to first register When it comes to writing, it's even worse: Wire.beginTransmission(Module_Address) //Use this to start transmission To read Wire.requestFrom(Module_Address, 3) //Read three registers Call me stupid, but I have the feeling like somebody told me that 1 + 1 = 2, and then gave me some polynomial equation to solve :(Īll book examples and almost all tutorials look like this imaginary example: Wire.beginTransmission(Module_Address) //Use this to start transmission I've read few books and too many tutorials, but I could summarise these in two:Ī) all tutorials are just showing the very basics of how to use these methods and b) they don't actually explain the steps, like everything is totally self explanatory. Being novice, I almost never use libraries that are already written by somebody, I try to create my class for module in order to truly understand how this module works and to learn how to manipulate with it.

I Googled this a lot, and it seems that I am not the only one having problems with really understanding Wire.write() and Wire.read().

Arduino wire library read from register