From:    Wolfram Liebchen <liebchen@FFO.FGAN.DE>
Subject: Re: Code for MAX 186 serial A/D

>>> Has anyone written code for the MAXIM 186 8-channel serial A/D
>>
>> (...)  What you really need is just
>>some good I2C routines to talk to the Maxim chips.  If you are
>>interested I can share my code with you, but unfortunately it was

> Why do you need I2C routines to communicate with the Maxim chips? They
> use SPI or Microwire (however you call it) and not I2C ?!?

Oops!  My apologies.  You are absolutely correct.  It has been about
2 years since I've finished this project, and since I also used
some I2C chips on the same project I somehow mistakingly thought that the
Maxim chips were I2C based.  Anyway, since a few people asked me for
the routines, here is the one I used to talk to the MAX 186 and as
Wofram pointed out, it is not I2C:   : )

//////////////////////////////////////////////////////////////////////
//  READ AD //  Clocks 10 bits A/D value in from one of eight
// channels selected by  the paramenter 'chan'.  It return the digital
// value as an integer   to the calling procedure.  Mostly called from
/ / the Main routine.
//////////////////////////////////////////////////////////////////////
/ int Read_AD( byte chan )
{
   int readval=0;
   char cnt;

   SCK = FALSE;                 // Just make sure that SCK is LOW at the start
   SHDN = 1;            // Power the A/D up
   CS0 = FALSE;                 // select ADC
                                                        // Indicate which
 channel to read
   for (cnt=0; cnt<8; cnt++)    // Clock the control byte into DIN
   {
      DIN = chan & 0x80;        // pass only MSB
      SCK = FALSE;                      // Toggle SCK
      SCK = TRUE;
      chan <<= 1;                                  // Rotate one position to the
 left
   }
   SCK = FALSE;                 // Toggle SCK between control and read
   SCK = TRUE;
                                                      //// read ad value
   for (cnt = 0; cnt < 10; cnt++)    // Clock the control byte intoDIN
  {
     readval <<= 1;
     SCK = FALSE;                       // Toggle SCK high
     SCK = TRUE;                        // Toggle SCK low
     DOUT = TRUE;                       // Pull DOUT high
     if (DOUT) readval++;
   }
   SCK=FALSE;                           // leave SCK lo at end
   CS0 = TRUE;                  // unselect ADC
   SHDN = 0;                    // Power down to conserve power.
   return readval;
}