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John C. Wren
5967 McEver Road
Flowery Branch, GA 30542


  • Sep 2006 To Present
Employee with Sargent Lock, Inc. Responsible for firmware for the networked line of smart locks for business and university campuses. Switched product line from PIC-based to ARM-based. Developed several test fixtures for automated testing of locks.
  • Nov 2003 To Sep 2006
Consultant to Single Access Lock Corporation. (Details)
  • Nov 2000 To Nov 2003
Consultant to Altius, LLC. Responsible for software in Altius' complete line of products. Projects included the Bellsouth FastForward cradle, the MacBox and EDR (Linux-based data recorder for vehicles that collects and reports vehicle position and engine data), the CoPilot (a GPS+Cellular device for vehicle tracking and driver emergency reporting), the Utility Modem (enables power meters to report data over a cellular modem), and all associated test fixtures for manufacturing Altius' products. (Details)
  • Dec 1999 To Nov 2000
Consultant to Enrev Corporation. Responsible for design and implementation of an extensive web based database management system for battery performance data, which included generating plots, Excel spreadsheets, and support for remote label printers. Other functions included converting an existing poorly structured database from Access to mySQL, and automating a number of management tasks. Designed and had produced an RS-485 hub board to increase reliability of interconnected battery test stations. (Details)
  • Apr 1999 To Oct 1999
Consultant to Avalex Corporation. Responsible for Hitachi SH/3 implementation of an avionics flight management system, coupling navigation information with weather radar overlays. Subsequently ported design to an embedded Windows-NT based system. Implemented firmware for an 8052-based ARINC 429 protocol converter for Blackhawk helicopters. (Details)
  • Aug 1998 To Apr 1999
Consultant to IBMs High Performance Server Group. Involved with design verification and bring-up of 4-way Pentium Xeon systems. Wrote custom software for checkout of IOAPICs, I2C busses, proprietary ASICs, etc. Designed Windows based program to unify HP BEST testers, Arium ICEs, I2C tools and other test equipment, combined with scripting, scheduling, remote access, and e-mail notification of test failures. Designed and implemented other various and sundry system tools. (Details)
  • Jan 1995 To Aug 1998
Principal Software Engineer, Hayes Microcomputer. Responsible for development and maintenance of large sections of the Optima 28.8/33.6 modem firmware. Designed and implemented protocol and firmware for SNMP manageable front panel for the rack modem product. Designed and implemented protocol and firmware for Hitachi SH/2 I/O processors in a Motorola PPC 860 based RAS server. Ported Apache web server to run under VxWorks for RAS server. Began design and implementation of a Visual Basic/SNMP/GPIB based automatic test suite for cable modems. (Details)
  • Aug 1994 to Jan 1995
Senior Software Engineer, Communications Technology Corporation. Responsible for development and maintenance of protected mode kernels, low-level drivers, debugging monitors, etc. on both 80486 and 68302 processors for the DAS-9000 Bit Error Rate Test Set, along with application support, and selection of software tools. (Details)
  • Oct 1993 to Aug 1994
Senior Electrical Engineer, Scientific Atlanta. Responsible for development of BIOS and low level support code for FDDI digital video compression card on a multiple RISC processor based architecture, application programmer support, and selection of software tools. (Details)
  • Nov 1989 to Oct 1993
Senior Systems Analyst, Tiger Labs Corporation, consulting firm. Responsible for majority of micro-controller software for customer hardware and in-house programming. Developed Intel 486 CPU BIOS for the Scientific Atlanta DAS-9000 Bit Error Rate Test Set. Implemented keyboard and power control processors in J.B. Hunts' on-board truck computer. Developed software for high-performance multiple serial port controller for Fisher Restaurant systems, and numerous micro-controller projects for IBM and other clients. (Details)
  • Nov 1986 to Oct 1989
Systems Programmer, Infosafe Corporation. Developed application software for the X-LOCK 50, a real time DES encryption system for PC security. Wrote DOS device drivers and application software for the X-LOCK 10 PC access control package. Wrote RSA based public/private key management software for a secure telephone. Implemented entire software portion of a Z80 based hand held radio security product, along with the 8031 based key management unit. (Details)
  • July 1983 to Oct 1986
Systems Programmer, Applied Micro Management Corporation. Developed, supported and maintained a number of software products relating to patient care in the nursing home industry. These included database management, patient care plan, general ledger, accounts receivable and employee payroll and timekeeping packages. (Details)

Langauge/Processor Skills:

  • High Level:
Perl, C, C++, PHP, Visual Basic, Forth, Pascal, Fortran, PL/M, PL/1, Ada, BASIC, JavaScript
  • Assembly:
Intel 80486 and variants, Intel 8031 and variants, Hitachi SH/2 & SH/3 family, Motorola 68000 family, Motorola 68HC11, Motorola 6809, Microchip PIC family, Zilog Z80 family, Intel 8096, Intel 80196, AMD 29000 RISC family.
  • Operating Systems:
Linux, Windows-NT, Windows-95/98, DOS, Unix, OS/2.
  • Software Packages:
Perl/DBI, Perl/CGI, mySQL, Apache, HTML, Protel, Excel, MS Word, Access
  • Protocols:
I2C, Dallas 1-wire, ARINC 429, HDLC, Ethernet, JTAG, AX25.


Experience with a number of programmable logic devices, such as Xilinx, Intel FLEX series and AT&T ORCA series. Good hardware and software debugging skills. Website development with CGI/SQL backends.

Other Projects:

Numerous Perl scripts for household control. DTMF decoder board for radio controlled weather station. Web-based camera and weather system. Power line stability monitor. 8031 based Ethernet interface device. I2C mux, I2C JTAG controller, I2C LCD controller for IBM. Automated call forwarding system for cellular phones for Bell South Mobility. ‘AT’ command processor for Celemetry radio for Bell South Mobility. Storage sub-system for multiple T1/E1 surveillance equipment. MIDI-based automated multi-projector slide controller for theatrical use. High speed A/D converter system, used in the testing of Chrysler air-bags for Allied Signal. Alarm reporting board used for Unix system reliability in cellular central offices. Automated dialer for reporting household power outages to power companies so as to comply with 1996 minimum service standards. Trigger-Guard prototype hardware and software, a system requiring a two-digit entry code to prevent an alarm when removing the device from a firearm. Software for reporting music played by Digital Music Express back to a PC for ASCAP royalty compliance. Automated system for testing high-performance IBM Microchannel multi-port serial cards.


Amateur radio (K4JCW, Extra class operator), boating, diving, photography, German Shepherds.


Available upon request.