The prototype of the AriCalculator (RevA) is no longer usable. It has been destroyed in an attempt to replace a broken FTDI USB to serial converter. After a first attempt to fix the prototype’s design flaws with incremental changes (RevB), I’ve decided to do a full redesign (RevC):
The new design no longer uses a milled PCB in combination with an S12-Micro-EVB. Instead it uses a single PCB, which makes assembly and repairs much easier. The new design has new features like an extended keypad (38 instead of 30 keys), an expansion port (SPI), and a back ight option for the display. However, it is not fully compatible to the previous designs.
PCBs and enclosures have already been ordered and should arrive in January 2015.