Is anyone else making heavy use of PID controllers?

I have an anova sous-vide controller generating cocoa butter seed; on the included picture it's set at 92.5F.

A ziploc bag at 34C for 12 hours then at 33.5C, up to 100g of cocoa butter seems to work well; I dry the bag and cut a tiny bit of a corner to use the seed, which takes care of any remaining lumps. It's also worked with a glass jar inside a ziploc bag. The same setup was also used at higher temperatures to infuse cocoa butter with spices.

On the second attached picture is another PID controller, this time a Sous-Vide Magic 1500. I used plexiglass, duct tape, a heater, fan and hacked chafing dish to assemble this heater. This probably doesn't make economic sense if you have to buy all those things - I had an old spare PID controller hanging around and wanted a proof of concept. I learned that ceramic heaters are a really bad choice and will use a hair dryer next

Next I'm getting quotes to build the box in stainless steel and cut the chafing dish holder that would sit on top, so I can use regular restaurant-sized chafing dishes.

In another chocolate workshop I saw a micro-controller running a PID algorithm, controlling an old freezer to keep it at a higher temperature than the one it was designed for. Arduino, Raspberry Pi and others would be good choices - and given time I would get some together to have a seed generator that isn't water based and maybe hack a freezer to be a cooling tunnel.

For the moment my bottleneck is molding bars and packaging them fast enough to be able to get to break-even, so those projects have to wait. I hope this gives people ideas and this thread encourages people to share.

updated by @daniel-haran: 02/10/16 14:46:08

Interesting. Did you use the seed straight out of the water bath, or did you let it cool/harden and then shave it into your chocolate?

Rice cooker (analog, because the power goes out here in Panama every once in awhile) connected to a Dorkfood sous vide temperature controller set at 93F.  Cocoa butter in small glass jars in baggies.  Probe from the controller into the rice cooker, held down with the lid.  Water in rice cooker up the side of the jars about half way. Total equipment cost about $125.  I've been using this for several months now and it works like a charm.  Perfectly tempered chocolate in minutes.  The water really isn't an issue, but I'm careful to pat the jar dry when I pull it out of the baggie and before I unscrew the top.

@volnoir I use it right away, otherwise it creates lumps. The chocolate is brought to working temperature before adding the butter, so the crystals don't melt. It seems anywhere around 31-32C is fine.

@deborah2 whoa! A $100 sous-vide controller, that's fantastic

In all fairness, I found it a few years ago as a result of Clay's post for a DIY melter , but I ended up using it for cooking dinner instead.  I recently bought another to use for a seed generator.