First post so please be gentle.

The prob­lem I have should be pretty sim­ple but I can’t seem to fig­ure it out or find a solution.

I have a Raspberry Pi B+ run­ning RetroPie Image v2.3. I have it con­fig­ured for mul­ti­ple SNES USB con­trollers, the hotkeys are enabled and it all works quite lovely.

Now, I have an old SNES and I want to mount my Pi in there and make use of the old Reset and Power Buttons. I have all of the mechan­i­cal stuff sorted out (3D print­ing a front panel for the USB con­trollers and a the rear panel for power, HDMI and CatV and a straight wire in for the power switch). The Reset Button is going to be a momentary Normally Open switch but I don’t which pair of GPIO pins to use and know what lines of code to add to which con­fig file. I would like the reset button to do what the START + SELECT combo already does; Exit the ROM back to the Emulation Station to select a different game.

Can you help at all? I’ve been down a google hole but I’ve had no joy. Thank you in advance.

My retroarch.cfg file is below and, like I say, works fine. Is this the file I would add to?

input_player1_joypad_index = 0
input_player1_b_btn = 2
input_player1_a_btn = 1
input_player1_y_btn = 3
input_player1_x_btn = 0
input_player1_l_btn = 4
input_player1_r_btn = 5
input_player1_start_btn = 9
input_player1_select_btn = 8
input_player1_l_y_plus = -1
input_player1_up_axis = -1
input_player1_l_y_minus = +1
input_player1_down_axis = +1
input_player1_l_x_minus = -0
input_player1_left_axis = -0
input_player1_l_x_plus = +0
input_player1_right_axis = +0
input_enable_hotkey_btn = 8
input_exit_emulator_btn = 9
input_enable_hotkey_btn = 8
input_save_state_btn = 4
input_enable_hotkey_btn = 8
input_load_state_btn = 5
input_player2_joypad_index = 1
input_player2_b_btn = 2
input_player2_a_btn = 1
input_player2_y_btn = 3
input_player2_x_btn = 0
input_player2_l_btn = 4
input_player2_r_btn = 5
input_player2_start_btn = 9
input_player2_select_btn = 8
input_player2_l_y_plus = -1
input_player2_up_axis = -1
input_player2_l_y_minus = +1
input_player2_down_axis = +1
input_player2_l_x_minus = -0
input_player2_left_axis = -0
input_player2_l_x_plus = +0
input_player2_right_axis = +0
input_enable_hotkey_btn = 8
input_exit_emulator_btn = 9
input_enable_hotkey_btn = 8
input_save_state_btn = 4
input_enable_hotkey_btn = 8
input_load_state_btn = 5