81 Controller Board

Controller-1 Manual image1-Edit-2


  • Powerful PIC18F46K22-I/ MV Microcontroller. 
  • Program in whatever language you want!
  • Off-the-shelf.
  • Eight I/O; analog; protected, buffered digital with pull-ups; and digital out. All at 5V TTL Levels.
  • Four common rail MOSFET outputs; 0.5A per MOSFET up to 40V DC each.
  • Separate VDD rail for MOSFET outputs.
  • Two module ports to expand capabilities via I2C bus.
  • Built in RS-232; either DB-9 or USB UART.
  • Built in RS-485.
  • Wide input voltage range:  9-30V DC.
  • Mode selector switch allows software to be written with many configurations and changed by the flip of a switch.
  • Board Dimensions:  6.76” x 5.26” ,  Max. component height 0.77” top of board
  • Designed and assembled in the U.S.A. 

The 81 control board is a unique platform that bridges the gap between the hobbyist “maker” boards and having a custom designed circuit board. Built around the powerful PIC18F46K22-I/MV microcontroller chip from Microchip, the 81 board offers a host of features that you would expect from an industrial controller board. Some of these features are standard RS-485 communication, RS-232, eight I/O lines that can be set as analog, protected and buffered digital input, or digital output, and four dedicated MOSFET outputs. In addition, two expansion module ports allow various add-on modules to be added to the control board to increase its functionality. Unlike the modules on the hobbyist boards which use valuable I/O lines for communication, the 81 board uses the SPI or I2C bus to communicate with its modules. This setup keeps the I/O lines to being just that; I/O.

The 81 board comes with pluggable headers for the input power, I/O, MOSFET outputs, and RS-485 lines. This feature allows all wiring to be done independently of the board. In addition, in a field service situation, to remove the board, simply unplug the headers. There is no need to unscrew and remove each wire from the terminal block and vice-versa to install a new board.

The RS-232 is an industry standard female DB-9 connector.

One of the greatest features of the 81 board that set it apart from the hobbyist boards or PLCs, is that the software can be written in any language that you wish, using any compiler that you wish, and be programmed using any programmer that you wish. All that is needed is the hex file and a compatible programming cable. 

© Graves Electronics LLC 2020