Went ahead and upgraded the code to include Orange MT reading for karts. Even though you are new to ASM, please read the source. You may have somewhat of an understanding of how I made the code work.
For a visual perspective... view the following image...
https://i.ibb.co/Yc5WsCx/meterdynamic.png
Dolphin was running when I took the screenshot, hence why the Code View is disabled. Anyway, address 0x80E495A2 holds the halfword value for Blue MT. Address 0x80E495A4 holds the halfword value for Orange MT. Also, address 0x80E495A1 holds a byte indicator (which I didn't need to use at all for the code, this is just a little fyi if you ever need it) which shows 0 for no charging of an MT, 1 for charging blue MT, 2 for blue MT charge full/charging orange MT, and 3 for orange MT charge full.
If at that moment of the screenshot, I set an instruction breakpoint (NTSC-U) for static function address 0x80590F20 (address of second ASM), Register 3 would hold the value of 0x80E494A4. If you add 0xFE to that address, you get 0x80E495A2 (location of blue MT). Hopefully that will help you understand the source for the second ASM, of why I added 0xFE to r3.
Ofc, these MT value locations/addresses are all dynamic (as I mentioned earlier). The very next race, all the MT values will be at a different spot (still high mem80 though).
For a visual perspective... view the following image...
https://i.ibb.co/Yc5WsCx/meterdynamic.png
Dolphin was running when I took the screenshot, hence why the Code View is disabled. Anyway, address 0x80E495A2 holds the halfword value for Blue MT. Address 0x80E495A4 holds the halfword value for Orange MT. Also, address 0x80E495A1 holds a byte indicator (which I didn't need to use at all for the code, this is just a little fyi if you ever need it) which shows 0 for no charging of an MT, 1 for charging blue MT, 2 for blue MT charge full/charging orange MT, and 3 for orange MT charge full.
If at that moment of the screenshot, I set an instruction breakpoint (NTSC-U) for static function address 0x80590F20 (address of second ASM), Register 3 would hold the value of 0x80E494A4. If you add 0xFE to that address, you get 0x80E495A2 (location of blue MT). Hopefully that will help you understand the source for the second ASM, of why I added 0xFE to r3.
Ofc, these MT value locations/addresses are all dynamic (as I mentioned earlier). The very next race, all the MT values will be at a different spot (still high mem80 though).