This question is an expansion of Hacking devices to unlock features: Legal or not?
I'm currently in possession of a laser measurement tool called Bosch GLM20 which is their most basic model. As per the manufacturer website it doesn't support several features of more advanced models: area/volume, indirect measurement, addition/substraction. These features are purely implemented in software and don't require additional hardware to function.
Would DMCA prevent me from taking the device apart and flashing my own custom firmware on the device that supports these features? The code will only utilize open source software and my own code contributions, so Bosch would not be able to claim copyright. The device in question is luckily simple enough that this is feasible for one person to do.
On the one hand, I will modify software to get access to features I didn't pay for. On the other, I'm flashing my own software onto the device and not using any copyrighted code.