First off I am trying to figure out if this is possible. Trying to use it to work with thermochromatic pigment that changes at 92F The pigment would be on a fabric with the heated wire on the other side. The fabric is quite thin, similar to a morphsuit. I would like to power it or at least control it with my Pi3 because I want to flip it on just long enough for it to heat up to that ~94F for a moment. My main issue I think I am going to run into is the max current across GPIO pins which seems to be around 16mA per pin or 50mA across all 3.3V pins in the rail. I want to power with a portable batter pack If there is a good way to control it from the Pi and use the power straight from one of the outputs on that battery pack that would work well too.
I will post back here if I find a solution on my own. Thanks for taking the time to read and or respond.
EDIT I guess I forgot to clearly post what my main question for this community is. Does anyone know if that low current output would even be enough to get something like 32 AWG Nichrome to around 100 degrees. Looking at the problem I think a good way to go about it would be to use the Pi to control some other circuit powered either straight from the battery pack or using a AA or 9V battery pack. However I have no idea what I need to purchase and how I would make such a circuit. I have an idea of what I want to do but I do not have the know how to accomplish it. Thank you again for taking the time to help me.