This application uses an MDM-1 as a digital voltmeter reading the ADC but
displaying the result on an external 4 digit, 7 segment multiplexed, common anode
LED display.  Common cathode can also be used by changing the logic.  The choice of
transistor is dependant on what you have available.  The MDM-1 display is not used
although could display something else if required.

Connections are made via the DMX display connector of the MDM-DEV board (RD0-6, RB3,
RB6 & RB7) with the addition of RE2.  The checksum of the code is 7B33.

The attached circuit diagram shows the connections.

Each display is on for approximately 5mS in 20mS.  This ensures no visible flicker.
Digit 1 is on for less time as it has the least number of segments on and this reduces
the brightness to give a more even display.

An ADC reading is taken approximately every 240mS.

Jal is provided free of charge and is regularly updated.  If you wish to
support the continued development of the code a donation, in dollars, can
be made to Wouter via http://www.piclist.com/support.

