title_body: Can "toy" drone FC firmware be tweaked? Can the flight controller of cheap &quot;toy&quot; grade quads, such as the Blade Inductrix, be programmed at all? I'd assume that even if it's possible, it wouldn't be practical. I don't have any experience with FC programming (yet).
upvoted_answer: TL;DR:
  Probably, but you'd likely be spending a lot of time locating a programming interface on the flight controller board and custom-compiling or custom-writing firmware to work on the special board configuration.
  Some more expensive toy-grade drones may have accompanying smartphone apps that allow you to change some flight parameters, but very few of those exist for a variety of reasons.
  In general, I wouldn't recommend trying to modify the firmware of cheap toy-grade drones...  It's almost certainly a better use of your time and money to begin tinkering with DIY drone parts that are meant to be tweaked.
  
  In the case of the OP's example toy drone, the Blade Inductrix FPV RTF, there is some limited good news. From looking at this image of the FC board, it can be discerned that the FC uses an off-the-shelf Atmel processor of some kind:
  
  I've tried rotating and zooming the image to find what exact model the chip is, but the image is too coarse to read the finer print. The fact that it uses an Atmel processor means that you could probably use a UART/ISP programmer device to upload new code once you locate and solder thin wires to the appropriate legs of the LQFP package. However, you'd likely run into other challenges when trying to modify or change the existing firmware:
  
  Attempting to de-compile the firmware on the FC to change PID constants or alike would be exceedingly difficult
  The Atmel chip is likely 8-bit, which would require adaptation of open-source FC firmware like Betaflight to work (Betaflight is designed to work with STM32/ARM 32-bit processors)
  The Atmel chip is almost certainly running at a slower clock speed and has less IPC capability than the chips used for DIY FPV drones and would require firmware with severely slimmed-down feature sets
  The pinout of the FC board is entirely unknown; you'd have to manually trace out the circuit to find which pins on the processor lead to what parts of the drone, or locate a schematic
  Critical peripherals like the IMU (accelerometers + gyroscopes), ESCs/H-bridges, RC RX, and FPV TX are likely non-standard components communicating with custom proprietary (or at least unknown) protocols that would require reverse-engineering
  etc.