One of the issue that with software test automation is the inability to interact with the physical world.
This means of you want to automate the test scripts of a POS software the most important business critical test scenarios are not getting executed since it demands interaction between different types of payment cards and card reader.
So we decided to make a robotic arm that can be controlled from Calabash in order to achieve 100% automation as a proof of concept.
Few days back we completed the Phase 1 of this robotic arm.
And it did meet our goals set for Phase 1 successfully.

Please find more about this project here:
https://nishabe.wordpress.com/2016/01/25/a-robotic-arm-integrated-with-calabash-2/