Rez for PlayStation 2 supported a "Trance Vibration" peripheral, a USB controller to fit in the player's pocket that provided stronger vibration than the Dual Shock 2 controller alone. In this thread on NintendoAge, WhatULive4 joked about a game supporting a "trance peripheral" for next year's compo.
So would it be worthwhile to make a Rumble Pak for the NES controller? I imagine it would send codes over the controller port like an SPI peripheral: To start or stop vibration on controller 1, write each bit of the code to $4016 and then read $4016 to clock player 1's port. To start or stop vibration on controller 2, write each bit of the code to $4016 and then read $4017. Codes might be, say, $E8 (11101000) for on and $E0 (11100000) for off.
But how much would it cost to make such a peripheral? I can think of a housing, a passthrough 7-pin connector, PCB, MCU, and vibration motor. Does the NES controller port pass enough current on +5V to spin a motor?
So would it be worthwhile to make a Rumble Pak for the NES controller? I imagine it would send codes over the controller port like an SPI peripheral: To start or stop vibration on controller 1, write each bit of the code to $4016 and then read $4016 to clock player 1's port. To start or stop vibration on controller 2, write each bit of the code to $4016 and then read $4017. Codes might be, say, $E8 (11101000) for on and $E0 (11100000) for off.
But how much would it cost to make such a peripheral? I can think of a housing, a passthrough 7-pin connector, PCB, MCU, and vibration motor. Does the NES controller port pass enough current on +5V to spin a motor?