Description: This circuit was created by Chris Barron (Yahoo group fixitsan2) and covered under a generous license agreement. This B7971 14 segment nixie driver board was originally done in the Eagle PCB design program but was redesigned in Proteus CADD for the production PWBs offered here while the circuit itself was changed as little as possible from the original design. A GUI is available for testing the serial communication of smart socket strings and includes a font editor for the B7971 SmartSocket UDC (User Defined Character) feature. See the B7971 page and download the Calculators installer <controllers>< SmartSocket> for more info. The protocol is also detailed in the help section of the GUI.
Testing: After assembly, these units are tested on an automated fixture for serial data in and out as well as functionality of each segment driver.
Floating #MCLR (Pin 4): These assemblies have the new R32 installed to pull up the #MCLR pin on the PIC.