How can I get cheats working on the My Boy! emulator?

See the developer's page for more info. Quoting from the source:

What cheat systems are supported?

• GameShark v1&v3 (As far as we know, Action Replay code is just GameShark v3). Format: XXXXXXXX YYYYYYYY
• Code Breaker. Format: XXXXXXXX YYYY
• Raw code. Format could be one of the following:
  • XXXXXXXX YY
  • XXXXXXXX YYYY
  • XXXXXXXX YYYYYYYY

OK, but where do I input cheat codes?

While you are in a game, select MENU -> Cheats.

I can't seem to get cheats to work. Why?

Well, good question! it could be quite a number of reasons:

• The cheat codes were not invented for your game, or your specific version of the game. There are often multiple variants of a single game. For example, cheats created for [1.0] of the game have little chance to be able to work on [1.1]. In this case, it may crash the game, cause graphics glitches, or simply do not work at all. Believe me, this is the number one reason why people can't get cheats to work.
• You may not mix different types of cheats. For example, Code Breaker master code may make GameShark cheat codes not to work.
• Some cheat codes have preconditions. For example, some are activated only when you are holding down certain buttons. Read the instructions carefully.
• If your cheat codes are for GameShark v1, or raw code, do not select "Auto detect" for code type. Select the right type explicitly.
• Your cheats are just wrong codes that are not supposed to work.
• There is a bug in My Boy!. Please report to us by email. Seriously this should be the last thing you consider, since the cheats system turned out to be robust.

As Pokemon Light Platinum is a Pokemon Ruby hack, chances are that you are trying to use the wrong codes.

No, it does not support Action Replay codes.

So far i've noticed that code breaker cheats work while gameshark v3 (action replay) rarely work. i am playing final fantasy tactics advance and my gameshark v3 codes do not work, auto select said they were valid codes but would never work. i finally got the cheats to work after reading the above text from the developer "You may not mix different types of cheats. For example, Code Breaker master code may make GameShark cheat codes not to work."