Serial Interface 7135 to 8751 Reads Analog
Using a ICL7135 A to D Convertor with a
Microcontroller is easy with the Serial Interface.
The advantage is you could use an Opto Coupler to
protect your Embedded System.
uC Input and Output I/O is Keyboard and LCD when
you build a Calculator or a Text/Morse
Communicator. When you control a motor it is
Drive/Speed and Direction for Motor and Tacho or
Opto Counters for Feedback. In both cases you have
Input and Output which is Logic or Analog which
has to reach the CPU.
Getting the analog into the uC is done here with
ICL7135, with a simple two wire serial interface.
Here a Pair of CD4538 MMV is used to shape the
pulse just right for uC data transfer,
ICL7135 Intersil, 8751-8031-8951, the circuit for uC
chips are not drawn in the circuit below as they are
in other circuits. See datasheets or application
The Busy signal and clock when anded (AND) will give
a burst of pulses. Count them and deduct 10,001 from
the virtual uC counter. This is the reading. See ICL7135 at