Fabricating a Temperature data Logger Using Arduino in two days

Recently friends  approached me requiring a data logger for a refrigeration system they were building for cooling harvested agricultural produce. I quickly put together a prototype using an Arduino Uno  and data logger shield. I demonstrated and they were overjoyed. At this point I could see the relief in their eyes with the automation in data collection so they do not have to bear the pressure of  reading and recording the temperature from  four thermometers every few seconds. The initial contraption is pictured below.

So after making a good first impression, I set out to create a device that will be cheaper than the off the shelf proof of concept device. I have been down this road before and the worry is the bugs that delay an otherwise smooth process. After about an hour of design time I converted the contraption to one file ready for Fabrication using Toner Transfer Method. Then parts were sourced and soldered and soldered after drilling and cutting PCB down to size. For code and circuits checkout the repository on bitbucket. Otherwise below are pictures of the quick and dirty prototype. 

Completed device showing the makeshift probes and the nice plastic housing

Complete device showing SLA backup battery and wall adaptor for charging

For a two day Fabrication exersise I feel good about this. To make it better a friend is smiling all the way to the Lab.