Revision A on Order

A project log for Base Convert

Simple desk/handheld calculator to convert between hexadecimal, decimal, and binary.

leumasyerrpleumasyerrp 07/14/2018 at 11:300 Comments

Revision A PCBs and hardware is on order. There are a few changes to this revision from the first prototype. First the separate binary keypad input had to be removed so that the PCB could be 100mm wide or less. There is a significant increase in cost when ordering PCBs from China when the board moves from 100mm on any side to 101mm or greater. Don't worry binary input is still possible using the decimal/hex keypad, see the silkscreen in the renders below for the layout. 

The 7 segment displays also shrank in size to fit in the new board width. I was able to find transparent red acrylic to place in front of the 7 segment display, the previous revision looked so much better after testing it out with a piece of the acrylic. To increase display brightness the batteries increased from 2x to 4x AA's for a few more volts to feed to the LEDs.

Another minor change was switching from the MSP430FR4133 which can drive an LCD to MSP430FR2033 that cannot drive an LCD since this design does not use an LCD, this shaves a few cents off the BOM cost.

Wanting this revision to look a little more polished I will have a front and back PCB on standoffs to make up a case. I played around with the silkscreen and copper layers to add a bit of decoration.

Below are renders of the assembly using files exported from KiCAD and then assembled into FreeCAD. I can't wait to look at the real thing.