In Mission Planner, when you change any parameter in the parameter list, say RC limits or PID; after pressing 'write parameters' the software updates the parameters.
I tried finding how does the same happen but to no avail (I don't know what it's called exactly). How does Mission Planner write parameters to already existing firmware on the APM board. Or it rewrites the firmware again with updated parameters?
I want to implement similar kind of procedure. To test with, I have an arduino board running a code. Instead of uploading entire code again and again, there must be a way to just update the value of a variable using some protocol (Serial) sent from the custom software on the PC. Just like updating a parameter when required. How to do it ?
Thanks.
The ATMEGA1280 used on the ArduPilotMega has a 4K EEPROM on-chip. Other MCUs used in Arduinos have EEPROM of varying capacity. The Arduino library includes support for it: https://www.arduino.cc/en/Reference/EEPROM
An EEPROM (Electrically Erasable Programmable Read-Only Memory) is a non-volatile memory technology similar to Flash, but with properties that make it more suited to storage of small amounts of configuration data, such as being byte level re-writable. It is much less dense (takes up more space) than flash memory, so is less suited to code storage.