Im reviving my 45 B&W photography passion. I have a Jobo CPE-2 processor which I purchased second-hand many years ago, but the temp controller is non-functional. I have created an Arduino based controller unit (in working prototype stage right now) that is mounted externaly, quite clumsily but it functions very well, even cooling the water bath, and maintaining 0.5F tolerance. I plan to incorporate more functions, i.e. timing and such, and I want to use (hack into the CPE-2 electronics) thus it would be VERY helpful if anyone has a schematic for said unit that they would share with me. Two additional thoughts. 1- If anyone else has made an Arduino based controller and wanted to offer advice Id be happy to listen. 2- Ill happily share my creation once it is fully functional with any one interested.