So really i just need the peltier to heat up/ cool and for the user to be able to touch it
That simplifies things a lot. You can just run the Peltier "open loop" without any temperature control, choosing a current for heating and another current for cooling. The efficiency of the Peltier is different, depending on which way the heat is flowing, so you will need to determine the two currents by experiment. Since this is part of a VR presentation, you should integrate a touch sensor with the Peltier device so the Peltier device IS the pushbutton.
The circuit for changing the direction of heat flow can be as simple as a DPDT relay: actuated it applies power to the Peltier device in a direction that causes the touch surface to heat; de-actuated it applies power in a direction that causes the touch surface to cool. A second relay can be used to turn power on and off if desired. An Arduino, or similar microcontroller/micorprocessor, can be easily programmed to turn on and off a MOSFET with logic-level gate actuation for pulse-width modulation of the current supplied to the Peltier device. Setting the duty-cycle in the PWM software routine to zero effectively turns the Peltier device off. Then you choose two other duty-cycles for heating and cooling by trial-and-error, remembering to associate the actuation/de-actuation of the heating/cooling relay with the appropriate duty-cycle. You can also use an H-bridge configuration (Google this) to control the heating direction as well as produce the PWM of the Peltier current.
Many ways to build a touch sensor integrated with the Peltier device, but that is a separate problem. You might consider capacitance-sensing circuits (there are integrated circuits available for this function) as well as membrane switches.
Do you have any experience with electrical or electronics circuits and the construction of same? Do you seek a "monkey see, monkey do" solution, such as you might find in an
Instructables project?
