File content as of revision 1:46c26c1de51f:

#include "mbed.h"
// Use SPI port to control MAX110/111 Analog to digital converter
// MAX110 is split-supply device, MAX111 single supply.
// Devices require 5v for full performance, may be testable at 3.3v
// 
//
// Conversion is SLOW. 
//
// Data is clocked in on rising edges so SPI 0,0 or SPI 1,1. 

Serial pc(USBTX, USBRX); // tx, rx

SPI spi(p5, p6, p7); // mosi, miso, sclk
DigitalOut max_cs(p22);
DigitalIn  max_busy(p23);

//module libmax110
//
//const
#define      max_12bit 0x9200
#define      max_13bit 0x8600
#define      max_14bit 0x8c00
#define      max_div4  0x0100
#define      max_div2  0x0080
#define      max_chan1 0x0000
#define      max_chan2 0x0010
#define      max_full  0x000c
//#define      max_gain  0b0000000000001000
#define      max_ofs   0x0004
//
//   procedure max_init(dim mode as word, dim byref port as //byte, dim cs,bf as byte)
//
//   mode must be one of max_12bit, max_13bit, max_14bit
//   mode may be modified by "or-ing" with max_div2 or max_div4 to set clock divider
//   mode may be modified by "or-ing" with max_chan1 or //max_chan2 to set input channel
//   mode may be modified by "or-ing" with a calibration type //max_full,max_ofs
//
//   port is the port the busy and cs pins are connected to (doesn't have to be PORTC)
//   cs is the bit number for the chip select pin
//   bf is the bit number for the busy flag pin
//
//   function max_read(dim byref data as integer) as boolean
//
// notes returns true if a value was read, immediately restarts converter
// otherwise returns false
//
// result is integer, valid results are from -16384 through 16383.
// values beyond this are overrange
//
//
// MAX110/111 Control register bits
// 15         !NOOP   Set to 1 for action, 0 for pass-through
// 14         NU, set to 0
// 13         NU, set to 0
//                             CONV 4,3,2,1
// 12         CONV4                 1 0 0 1  20ms
// 11         CONV3                 0 0 1 1  40ms
// 10         CONV2                 0 1 1 0  160ms
//  9         CONV1                 0 0 0 0  200ms SPECIAL
//                    SPECIAL = NO INTERNAL GAIN CALIBRATION, FIX IN SOFTWARE
//  8         DV4           1=DIVIDE XCLK BY 4
//  7         DV2           1=DIVIDE XCLK BY 2
//
//  6         NU, set to 0
//  5         NU, set to 0

//  4         CHS               0:CHANNEL 1   1:CHANNEL2
//
//                                    CAL NUL FUNCTION
//                                     1   1   INTERNAL ZERO (PERFORM FIRST)
//  3         GAIN CAL                 1   0   INTERNAL GAIN (NEXT)
//  2         OFFSET NUL               0   1   INPUT NUL (LAST)
//                                     0   0   NORMAL CONVERT
//  1         PDX POWER DOWN OSC
//  0         PD POWER DOWN ADC
//
//
unsigned int max_mode; 
//
void max_setup(unsigned int mmode)
{
  max_mode=mmode;
      pc.printf("setup %x\n",max_mode);
  max_cs=0;
      wait_us(1);
      spi.write((max_mode & 0xff00) >> 8);
      spi.write(max_mode & 0xff);
  max_cs=1;
}


int max_read(int *data)
{
  if (max_busy)
  {
    if (max_mode & 0x0c)
    {
      max_mode = max_mode - 0x04;
      pc.printf("cal %x\r\n",max_mode);
      
      max_cs=0;
      wait_us(1);
      spi.write((max_mode & 0xff00) >> 8);
      spi.write(max_mode & 0xff);
      max_cs=1;
      wait(0.1);
      return(false);
    }
    else
    {
      short t;
      max_cs=0;
      wait_us(1);
      t    =spi.write((max_mode & 0xff00) >> 8);
      t    =spi.write(max_mode & 0xff) | (t<<8);
      *data= (int) t;
      max_cs=1;
      return(true);
    }
  }
  else
  {
    return(false);
  }
}


int main() {
    spi.format(8,0);
    spi.frequency(100000);
    pc.printf("Start converter\r\n");
    max_setup(max_14bit | max_full);
//    max_busy.mode(PullUp);
    while(1) {
      int val;
      val=0;
      if (max_read(&val))
      {
        pc.printf("Readout: %d \r",val);
//        wait(1);
      }
    }
}