I would like to use the DUE board to implement a PID controller to drive a small (3.6 V, 0.6 A max) Peltier element. I have already performed some tests using a UNO board, converting a PWM output to a real analog DC value using a simple RC filter, and feeding it to a follower (OPAMP+Transistor) to drive the small Peltier element.
The circuit "as it is" on the UNO is able to stabilize the temperature with an accuracy of 0.3 Celsius (using the standard PID libraries I found on internet for Arduino), but at the moment I am limited by the ripple and decay time of the RC.
Now I would like to implement the circuit on the DUE, using the integrated DAC (avoiding the use of the RC filter), and implementing all the circuit on a proto-shield. My idea is to power the DUE using a 12V 1 A DC power adapter, using the 5V output pin to drive the OPAMP, the transistor (soldered on the shield) and the Peltier. My concerns are about the maximum current that the 5V output pin can draw.
During my tests with the UNO I fed the Peltier driving circuit (OPAMP+Transistor+Peltier) with an independent external power supply, and I noted that the Peltier driving circuit drew a maximum current of 0.5A when set to -40 Celsius, that is the minimum temperature I need to use. When set to -10 or -20 the current draw was obviously lower, of the order of 0.2,0.3 A.
Thus, the question is: is it safe to draw something like 0.5 A from the DUE 5V output pin, biasing the DUE with a 12V 1A DC power adapter?
Thank you in advance
Alessandro